Lube Oil Predictive Maintenance Handling, And Quality Assurance Guideline

Lube Oil Predictive Maintenance, Handling, and Quality Assurance Guideline

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WARNING: Please read the License Agreement on the back cover before removing the Wrapping Material.

Technical Report

Lube Oil Predictive Maintenance, Handling, and Quality Assurance Guideline 1004384

Final Report, December 2002

EPRI Project Manager R. Chambers

EPRI • 3412 Hillview Avenue, Palo Alto, California 94304 • PO Box 10412, Palo Alto, California 94303 • USA 800.313.3774 • 650.855.2121 • [email protected] • www.epri.com

DISCLAIMER OF WARRANTIES AND LIMITATION OF LIABILITIES THIS DOCUMENT WAS PREPARED BY THE ORGANIZATION(S) NAMED BELOW AS AN ACCOUNT OF WORK SPONSORED OR COSPONSORED BY THE ELECTRIC POWER RESEARCH INSTITUTE, INC. (EPRI). NEITHER EPRI, ANY MEMBER OF EPRI, ANY COSPONSOR, THE ORGANIZATION(S) BELOW, NOR ANY PERSON ACTING ON BEHALF OF ANY OF THEM: (A) MAKES ANY WARRANTY OR REPRESENTATION WHATSOEVER, EXPRESS OR IMPLIED, (I) WITH RESPECT TO THE USE OF ANY INFORMATION, APPARATUS, METHOD, PROCESS, OR SIMILAR ITEM DISCLOSED IN THIS DOCUMENT, INCLUDING MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, OR (II) THAT SUCH USE DOES NOT INFRINGE ON OR INTERFERE WITH PRIVATELY OWNED RIGHTS, INCLUDING ANY PARTY'S INTELLECTUAL PROPERTY, OR (III) THAT THIS DOCUMENT IS SUITABLE TO ANY PARTICULAR USER'S CIRCUMSTANCE; OR (B) ASSUMES RESPONSIBILITY FOR ANY DAMAGES OR OTHER LIABILITY WHATSOEVER (INCLUDING ANY CONSEQUENTIAL DAMAGES, EVEN IF EPRI OR ANY EPRI REPRESENTATIVE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES) RESULTING FROM YOUR SELECTION OR USE OF THIS DOCUMENT OR ANY INFORMATION, APPARATUS, METHOD, PROCESS, OR SIMILAR ITEM DISCLOSED IN THIS DOCUMENT. ORGANIZATION(S) THAT PREPARED THIS DOCUMENT EPRI

ORDERING INFORMATION Requests for copies of this report should be directed to EPRI Orders and Conferences, 1355 Willow Way, Suite 278, Concord, CA 94520, (800) 313-3774, press 2 or internally x5379, (925) 609-9169, (925) 609-1310 (fax). Electric Power Research Institute and EPRI are registered service marks of the Electric Power Research Institute, Inc. EPRI. ELECTRIFY THE WORLD is a service mark of the Electric Power Research Institute, Inc. Copyright © 2002 Electric Power Research Institute, Inc. All rights reserved.

CITATIONS This report was prepared by EPRIsolutions 3412 Hillview Ave. Palo Alto, CA 94304 Principal Investigators G. VanDerHorn, EPRIsolutions R. Wurzbach, Noria Corporation This report describes research sponsored by EPRI. The report is a corporate document that should be cited in the literature in the following manner: Lube Oil Predictive Maintenance, Handling, and Quality Assurance Guideline, EPRI, Palo Alto, CA: 2002. 1004384.

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REPORT SUMMARY

This guideline has been prepared by EPRI to assist member utilities in the improvement of maintenance processes. It presents the key elements that should be included in the conduct of comprehensive lubrication program evaluations and in setting up a well-organized lubrication program. EPRI believes that organizational and procedural improvements can be made by utilities that will yield optimal lubrication programs. This guideline also serves as an excellent reference document because it describes key lubrication tools, processes, and procedures. It defines how these elements can contribute to plant operations when they are incorporated into maintenance strategies and assigned the proper priority. Background EPRI has for many years supported developments in the improvement of maintenance practices to increase equipment reliability and availability and to reduce costs. These maintenance improvement programs started with the development of monitoring and diagnostic instrumentation, which then progressed to the implementation of complete predictive maintenance (PdM) programs. Equipment maintenance guidelines were developed and, finally, the overall optimization of maintenance practices evolved. In the course of these activities, technology has always played an important role in the maintenance improvement process. Vibration, thermography, and oil analyses were identified early on as the fundamental backbones of a good basic machinery condition-monitoring program, which is all-important for the success of any maintenance optimization program. This guideline focuses on describing the elements of a good lubrication program, the valuable information that a good lubrication program produces, how such a program will benefit plant equipment life and operations, and how to set up a meaningful and productive program. Objectives • To provide a comprehensive reference of information gathered from EPRI’s years of knowledge and expertise in the development of lubrication maintenance tools and strategies •

To combine and incorporate the extensive experience of EPRI personnel, lubrication suppliers, testing laboratories, and utilities into a comprehensive and meaningful reference document that will help utilities to realize the benefits of a quality lubrication program

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Approach Extensive industry information, taken from the experience of long-standing EPRI personnel, lubrication suppliers, testing laboratories, and utilities, was gathered and compiled. An extensive literature search for information related to lubrication technology was conducted and included a review of EPRI reports, International Organization for Standardization (ISO) standards, military specifications, Society of Automotive Engineers (SAE) publications, and U.S. Nuclear Regulatory Commission (NRC) notices. To support this experiential data, lubrication audits were initiated at utility sites, and the findings of those assessments are also included in this guideline. Results The activities required to improve maintenance effectiveness are many and varied. This guideline focuses on the area of lubrication maintenance and is designed to provide utilities with the information necessary to improve an existing lubrication program or to develop a new program. It identifies key aspects of a well-run lubrication maintenance program, and it also defines the specific tools necessary to implement a new program. This guideline provides the end user with a comprehensive reference for improving the lubrication maintenance process. EPRI Perspective The preparation of reliable maintenance process improvement guidelines provides a significant advantage for the power industry in the competitive market that it has been facing in recent years. EPRI-member utilities have realized substantial benefits by implementing many of the maintenance processes, condition-monitoring tools, and predictive maintenance programs that have been developed by EPRI. The goals leading to improved oil PdM, handling, and quality assurance have not been met, however, in all cases. This lubrication guideline identifies areas that need improvement in order to achieve best practices goals, and it defines the tools that can be used as part of a utility’s continuous improvement efforts needed to maintain its competitive position. Keywords Lubrication Lube oil Lube oil sampling Oil Oil analysis Predictive maintenance

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EPRI Licensed Material

ABSTRACT Plant maintenance is an important function that produces significant benefits in machinery operation and plant reliability and availability. A good maintenance program comprises many elements, including the application of various technologies to monitor the condition of critical plant machinery. EPRI realizes that most utilities have implemented lubrication controls and analysis programs to varying degrees; however, industry data indicate that a great deal more can be done. Recent experience has shown that applying the technologies associated with lubrication management in power plants provides very good short-term benefits and has significant potential for medium and long-term benefits as well. At host plants or sites, EPRI plans to perform evaluations of what is currently being done in defined areas, such as sampling, testing, filtration and reclamation, health, environment, and safety. Based on the evaluation results, EPRI will make specific recommendations for improvement in the elements deemed essential to an effective and beneficial lubrication management program, from purchasing to the final test and action phases. This guideline focuses on the elements that constitute a good lubrication program and provides detailed descriptions of each element that should be considered when setting up a meaningful program. These key elements are: •

Standards, consolidation, and procurement

•

Storage and handling

•

Sampling techniques

•

Contamination control

•

Training, skill standards, and certification

•

Lubricant analysis

•

Lubrication/relubrication practices

•

Program management

•

Procedures and guidelines

•

Program goals and metrics

•

Safety practices

•

Continuous improvement

An important value of the guideline is to provide utility plants with the tools to evaluate their existing lubrication practices and to compare them with best practices industry standards. Utilities can then determine where their lubrication program can be improved and how to make that happen. vii


ACKNOWLEDGMENTS EPRI would like to thank the following individuals for their contributions to the publication of this guideline: Patrick Abbott, EPRIsolutions Ellie Cherry, EPRIsolutions Jim Fitch, Noria Corporation John Niemkiewicz, EPRIsolutions Drew Troyer, Noria Corporation

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CONTENTS

1 INTRODUCTION AND OVERVIEW .......................................................................................1-1 Program Development ..........................................................................................................1-1 Audit Process ........................................................................................................................1-2 On-Site Audit ....................................................................................................................1-2 Audit Report......................................................................................................................1-3 Implementation Plan..............................................................................................................1-4 Implementation Plan Development...................................................................................1-4 Technical Assistance and Follow-Up Audit ......................................................................1-7 Lube Oil PdM, Handling, and Quality Assurance Guideline Report ......................................1-7 2 STANDARDS, CONSOLIDATION, AND PROCUREMENT ..................................................2-1 Consolidation—Optimizing the Use of Lubricant Products....................................................2-2 Determining the Consolidation Approach .........................................................................2-3 Phase I—Brand Consolidation .........................................................................................2-4 Phase II—Technical Consolidation...................................................................................2-6 Phase III—Generic Specifications ....................................................................................2-8 Using a Database for Continuous Improvement.............................................................2-12 Quality Assurance and Receipt Inspection..........................................................................2-12 Testing............................................................................................................................2-14 Quarantine......................................................................................................................2-15 Q-Class Lubricants for Nuclear Power ...........................................................................2-16 3 STORAGE AND HANDLING .................................................................................................3-1 Health, Safety, and Environmental Issues ............................................................................3-8 Dispensing Systems..............................................................................................................3-9 Lubrication Technicians and the Digital Age .......................................................................3-11 Lubricant Storage and Handling..........................................................................................3-12

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4 SAMPLING TECHNIQUES ....................................................................................................4-1 Sample Points .......................................................................................................................4-1 Sampling Port Location—General Discussion ......................................................................4-2 Case A—Dry Sump, Horizontal Drain Line.......................................................................4-3 Case B—Dry Sump, Vertical Drain-Line...........................................................................4-3 Case C—Pressurized Feed Line ......................................................................................4-4 Case D—Pressurized Return Line ...................................................................................4-6 Case E—Wet Sump, Splash, or Bath Lubrication ............................................................4-7 Case F—Wet Sump, Circulating Lubrication ..................................................................4-10 Power Generation Specific Sampling Locations .................................................................4-11 5 CONTAMINATION CONTROL...............................................................................................5-1 Contaminant Identification.....................................................................................................5-2 Particulate Contamination ................................................................................................5-4 Moisture............................................................................................................................5-7 Coolant .............................................................................................................................5-9 Fuel and Soot .................................................................................................................5-10 Air ...................................................................................................................................5-11 Oxidation Products .........................................................................................................5-13 Contaminant Elimination .....................................................................................................5-15 Particulate.......................................................................................................................5-15 Filter Media.....................................................................................................................5-19 Filter Location Options ...............................................................................................5-20 Water ..............................................................................................................................5-21 Glycol, Fuel, and Soot ....................................................................................................5-23 Air ...................................................................................................................................5-23 Oxidation Products .........................................................................................................5-25 Contaminant Exclusion........................................................................................................5-27 Sealing the Machine .......................................................................................................5-28 Shaft Seals ................................................................................................................5-28 Lids, Access Ports .....................................................................................................5-29 Keeping Out Water ....................................................................................................5-31 Filtering the Vent ............................................................................................................5-32 Breather Filters ..........................................................................................................5-32 Desiccant ...................................................................................................................5-33 Bladders and Expansion Chambers ...............................................................................5-34

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6 TRAINING, SKILL STANDARDS, AND CERTIFICATION ....................................................6-1 Lubrication Training...............................................................................................................6-1 Reliability and PdM Analyst ..............................................................................................6-2 Lubrication Technicians....................................................................................................6-2 Oil Analysts.......................................................................................................................6-3 Mechanics ........................................................................................................................6-3 Operators..........................................................................................................................6-4 Managers and Supervisors...............................................................................................6-4 Knowledge and Skill Certification ..........................................................................................6-4 On-the-Job Training (OJT) ...............................................................................................6-6 7 LUBRICANT ANALYSIS........................................................................................................7-1 Determining the Case for On-Site Versus Outsourced Oil Analysis......................................7-1 Evolving from a Conventional Oil Analysis Program to a Modern One .................................7-4 Setting Up Facilities for On-Site Analysis..............................................................................7-5 Work Area and Health and Safety ....................................................................................7-6 Housekeeping...................................................................................................................7-6 Computers ........................................................................................................................7-7 Lubricant Testing ..............................................................................................................7-7 Wear Condition.................................................................................................................7-8 Lubricant Properties .......................................................................................................7-10 Contaminants .................................................................................................................7-16 Mini-Lab Analysis Testing...............................................................................................7-18 Sensory Tests.................................................................................................................7-21 Analysis Frequency .............................................................................................................7-21 Predictive Versus Proactive............................................................................................7-21 Optimizing with a Sample Frequency Generator............................................................7-23 Economic Penalty of Failure ......................................................................................7-25 Fluid Environment Severity ........................................................................................7-25 Machine Age ..............................................................................................................7-25 Oil Age .......................................................................................................................7-26 Target Tightness ........................................................................................................7-26 Putting Sampling Intervals to Work............................................................................7-26 Test Slates ..........................................................................................................................7-27

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8 LUBRICATION/RELUBRICATION PRACTICES...................................................................8-1 Maintenance Filling of Lubricated Equipment .......................................................................8-1 Level Checking and Top-Off of Oil Lubricated Equipment ....................................................8-5 Greasing................................................................................................................................8-8 Greasing on a Time-Based Interval..................................................................................8-8 Greasing Tools and Equipment ...................................................................................8-8 Avoiding Over-Greasing.............................................................................................8-12 Condition-Based Greasing .............................................................................................8-14 9 PROGRAM MANAGEMENT ..................................................................................................9-1 Dedicated Ownership of the Lubrication Program.................................................................9-2 Roles and Responsibilities ....................................................................................................9-3 Communication .....................................................................................................................9-4 Quantifying the Benefits of a Lubrication Program................................................................9-4 Proactive and Predictive Benefits.....................................................................................9-5 Basic Assumptions ...........................................................................................................9-6 Program Management Summary ..........................................................................................9-7 10 PROCEDURES...................................................................................................................10-1 Lubrication Procedures .......................................................................................................10-1 Importance of Lubrication Procedures............................................................................10-1 Elements of an Effective Lubrication Procedure.............................................................10-2 Procedure Topics ................................................................................................................10-2 Cleaning and Reconditioning Containers .......................................................................10-3 Flushing Systems After Overhaul or Repair ...................................................................10-3 Conducting an Oil Change .............................................................................................10-4 Lubricant Sampling Procedures .....................................................................................10-4 Lubricating Machines......................................................................................................10-4 Procedure Considerations...................................................................................................10-4 Strategy ..........................................................................................................................10-5 Purpose ..........................................................................................................................10-5 Procedure .......................................................................................................................10-6 Right Product .............................................................................................................10-6 Right Place ................................................................................................................10-7 Right Amount .............................................................................................................10-7

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Right Time .................................................................................................................10-8 Right Attitude .............................................................................................................10-8 11 PROGRAM GOALS AND METRICS .................................................................................11-1 Establishment of Specific Program Goals and Metrics .......................................................11-1 Reduce Lubricant Costs .................................................................................................11-2 Improve the Percent Compliance to Scheduled Lubrication PM Tasks..........................11-2 Adjust or Redefine Analysis Alert or Alarm Limits ..........................................................11-2 Improve Equipment Reliability ........................................................................................11-3 Improve Oil Cleanliness Levels ......................................................................................11-3 Lubricant Disposal Costs................................................................................................11-3 12 SAFETY PRACTICES ........................................................................................................12-1 Storage................................................................................................................................12-1 Handling ..............................................................................................................................12-3 In and Around Machines .....................................................................................................12-4 Sampling .............................................................................................................................12-5 Disposal ..............................................................................................................................12-6 13 CONTINUOUS IMPROVEMENT ........................................................................................13-1 Procedures and Guidelines .................................................................................................13-1 Oil Sampling and Analysis...................................................................................................13-1 Work Closeout.....................................................................................................................13-2 Culture Change ...................................................................................................................13-2 Customer Satisfaction .........................................................................................................13-3 Adopting Continuous Improvement Behaviors ....................................................................13-3 Failure Modes Effects Analysis (FMEA)..............................................................................13-3 The FMEA Process ........................................................................................................13-4 The LUBE FMEA ............................................................................................................13-7 Lubrication Functions and Failure Mechanisms ................................................................13-10 The Concept of Continuous Improvement.........................................................................13-13 14 REFERENCES ...................................................................................................................14-1

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A PROCEDURE FOR INSTALLATION OF LUBRICATION OIL SAMPLING VALVE FITTINGS FOR PLANT EQUIPMENT...................................................................................... A-1 B TEST SLATES ...................................................................................................................... B-1 C TRICO MANUFACTURING CORP. TECHNICAL REFERENCE FOR TRICO OILERS...... C-1

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LIST OF FIGURES Figure 1-1 Lube Oil Audit Spider Chart......................................................................................1-3 Figure 1-2 Action Item Matrix.....................................................................................................1-5 Figure 1-3 Microsoft Project Schedule – Implementation Plan ..................................................1-6 Figure 2-1 Suppliers’ Recommendations...................................................................................2-2 Figure 2-2 Typical Lubricant Table ............................................................................................2-5 Figure 2-3 Lubricant Identification..............................................................................................2-6 Figure 2-4 Screen from Access Database .................................................................................2-7 Figure 2-5 Screen from Access Database .................................................................................2-7 Figure 2-6 Screen from Access Database .................................................................................2-8 Figure 2-7 Typical Generic Lubrication Specification...............................................................2-10 Figure 2-8 Typical Generic Lubrication Specification...............................................................2-11 Figure 2-9 Source of Contamination ........................................................................................2-13 Figure 2-10 Appropriate Storage Area.....................................................................................2-13 Figure 2-11 Leaking Container ................................................................................................2-14 Figure 2-12 Establish Quarantine Area....................................................................................2-15 Figure 2-13 Drum Re-Closure Tap and Caps ..........................................................................2-16 Figure 3-1 Potential Contamination from Outdoor Storage........................................................3-1 Figure 3-2 Correct Progression of Usage ..................................................................................3-2 Figure 3-3 Storage of Parts in a “Clean Room” .........................................................................3-3 Figure 3-4 Drum Resealing Tool................................................................................................3-4 Figure 3-5 Central Dedicated Storage Reservoirs .....................................................................3-5 Figure 3-6 Storage Locker .........................................................................................................3-6 Figure 3-7 Transfer Containers..................................................................................................3-7 Figure 3-8 Drum Stacker..........................................................................................................3-10 Figure 3-9 Filter Cart................................................................................................................3-11 Figure 3-10 Gravity Feed Lube Station....................................................................................3-13 Figure 3-11 Seavan Container.................................................................................................3-14 Figure 4-1 Drain Line Sample Points .........................................................................................4-3 Figure 4-2 Vertical Drain Line with Sample Trap .......................................................................4-4 Figure 4-3 Pressurized Feed Line Options ................................................................................4-5 Figure 4-4 High-Pressure Line with Mini-Mess Valve ................................................................4-6 Figure 4-5 Pressurized Hydraulic System..................................................................................4-7

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Figure 4-6 Wet Sump Sampling Options ...................................................................................4-8 Figure 4-7 Two-Way Valve for Sight-Glass Sampling................................................................4-9 Figure 4-8 Sampling with Portable Off-Line Cart .......................................................................4-9 Figure 4-9 Circulating System – Wet Sump.............................................................................4-11 Figure 5-1 Machine with Checkpoints........................................................................................5-1 Figure 5-2 High-Efficiency Filter Breather..................................................................................5-3 Figure 5-3 ISO Standard............................................................................................................5-5 Figure 5-4 Flash Point Indicator...............................................................................................5-10 Figure 5-5 Foaming in Turbine Reservoir ................................................................................5-12 Figure 5-6 Continuous Filtration Machine ................................................................................5-16 Figure 5-7 Filter Operation Checkpoints ..................................................................................5-16 Figure 5-8 Turbine Oil Purifier..................................................................................................5-17 Figure 5-9 Determining Beta Rating ........................................................................................5-19 Figure 5-10 Filtered Machine Fill .............................................................................................5-21 Figure 5-11 Reducing Air Problems in Oil Reservoirs .............................................................5-24 Figure 5-12 Electrostatic Precipitation .....................................................................................5-26 Figure 5-13 Filter Cartridge......................................................................................................5-27 Figure 5-14 Transfer Containers..............................................................................................5-28 Figure 5-15 Labyrinth Seal.......................................................................................................5-29 Figure 5-16 Missing Screws on Sight-Glass ............................................................................5-30 Figure 5-17 Open Hatch ..........................................................................................................5-30 Figure 5-18 Modifications to Hatch ..........................................................................................5-31 Figure 5-19 Turbine Reservoir Hatch.......................................................................................5-31 Figure 5-20 Filter Breather.......................................................................................................5-33 Figure 5-21 Desiccated Filter Breather ....................................................................................5-33 Figure 5-22 Expansion Chambers ...........................................................................................5-34 Figure 6-1 Example of Skill-Based Matrix..................................................................................6-2 Figure 6-2 Skills Evaluation .......................................................................................................6-6 Figure 6-3 Required Certification for Job Functions ..................................................................6-6 Figure 7-1 Ferrous Wear Monitors.............................................................................................7-8 Figure 7-2 Elemental Analysis Methods ....................................................................................7-9 Figure 7-3 Common Wear Modes............................................................................................7-10 Figure 7-4 Device Used to Measure Kinematic Viscosity ........................................................7-12 Figure 7-5 Device Used to Measure Absolute Viscosity ..........................................................7-13 Figure 7-6 Titration...................................................................................................................7-14 Figure 7-7 RULER Device .......................................................................................................7-15 Figure 7-8 Karl Fischer Titrator ................................................................................................7-17 Figure 7-9 FTIR Analyzer.........................................................................................................7-17 Figure 7-10 Entek Mini-Lab......................................................................................................7-18

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Figure 7-11 Computational Systems Inc. (CSI) Mini-Lab.........................................................7-19 Figure 7-12 Approach to Oil Analysis Program........................................................................7-22 Figure 7-13 Sample Frequency Generator ..............................................................................7-24 Figure 7-14 “Bathtub Curve” – Probability of Equipment Failure .............................................7-25 Figure 8-1 Portable Filtration Rig ...............................................................................................8-2 Figure 8-2 Labeling of Oil Disposal Container ...........................................................................8-3 Figure 8-3 Drip-Type and Bottle-Type Oilers .............................................................................8-3 Figure 8-4 Unshielded/Unsealed Bearing ..................................................................................8-5 Figure 8-5 Bull’s-Eye Level Indicator without Placard................................................................8-6 Figure 8-6 Sight-Glass with Information Placard .......................................................................8-6 Figure 8-7 Lever-Style Grease Gun...........................................................................................8-9 Figure 8-8 Air-Powered Grease Gun .........................................................................................8-9 Figure 8-9 Grease Guns with Clear Tubes ..............................................................................8-10 Figure 8-10 Vent Plugs and Relief Fittings ..............................................................................8-11 Figure 8-11 Cleaned Grease Gun Nozzle................................................................................8-12 Figure 8-12 Ultrasonic Condition-Based Greasing Devices.....................................................8-15 Figure 11-1 Cleanliness Goals KPI Display .............................................................................11-3 Figure 12-1 Portable Berms.....................................................................................................12-2 Figure 12-2 Area Lubricant Notification Sign ...........................................................................12-2 Figure 12-3 MSDS Properly Located .......................................................................................12-3 Figure 12-4 Spill-Response Kit ................................................................................................12-4 Figure 12-5 Incorrect Lubricant Disposal .................................................................................12-6 Figure 12-6 Clearly Marked Receptacle ..................................................................................12-7 Figure 13-1 FMEA Process......................................................................................................13-4 Figure 13-2 Lube FMEA System Impact Assessment Worksheet ...........................................13-9

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LIST OF TABLES Table 1-1 Sampling Techniques ................................................................................................1-4 Table 4-1 Power Plant Equipment/Lubrication Systems ..........................................................4-12 Table 5-1 Lubricant Test/Contaminations ..................................................................................5-2 Table 7-1 Lubricant Property Tests..........................................................................................7-11 Table 7-2 Tests Used to Monitor Contaminants ......................................................................7-16 Table 7-3 List of Some Mini-Lab and Equipment Suppliers .....................................................7-20 Table 7-4 Test Slates...............................................................................................................7-27 Table 9-1 Total Life Extension ...................................................................................................9-5 Table 13-1 Severity Rating ......................................................................................................13-6 Table 13-2 Failure Occurrence Frequency Assessment..........................................................13-6 Table 13-3 Warning Period Rating...........................................................................................13-7 Table 13-4 Lubrication Functions Table.................................................................................13-10 Table 13-5 Lubrication Failure Mechanisms ..........................................................................13-11

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1

INTRODUCTION AND OVERVIEW

EPRI realizes that most utilities have implemented lubrication controls and analysis programs to varying degrees; however, industry data indicate that a great deal more can be done. Although recent experience has shown that applying the technologies associated with lubrication management in power plants can provide significant benefits, many plants struggle to define and implement a quality lubrication program. To this end, EPRI has been tasked to define and develop the guidelines for such a program. EPRI has also been tasked to develop a lube oil predictive maintenance (PdM), handling, and quality assurance guideline to support plants that are implementing such a program. To meet these challenges, the EPRI Monitoring and Diagnostics (M&D) Center teamed with lubrication industry experts, such as Noria Corporation, to develop a comprehensive lubrication program that would address both technical and programmatic aspects required for implementation.

Program Development Program development first focused on identifying key elements, or areas that should be included in a comprehensive lubrication program. Each element was then carefully reviewed by the EPRI team to identify required activities or practices that should exist within that element. A literature search was performed to identify the current best practices associated with each element. Previous industry experiences were considered as the key elements were selected. Following is the list of lubrication program key elements that were identified: •

Standards, consolidation, and procurement

•


•

Sampling techniques

•

Contamination control

•

Training, skill standards, and certification

•

Lubricant analysis

•

Lubrication/relubrication practices

•

Program management

•

Procedures and guidelines

•

Program goals and metrics

•

Safety practices

•

Continuous improvement 1-1

EPRI Licensed Material Introduction and Overview

To validate each key element and capture additional industry best practices, EPRI proposed a Tailored Collaborative (TC) project to perform lubrication program audits at member utility sites. Several members have participated in this effort and others are in the process of scheduling the audits.

Audit Process On-Site Audit The TC audit process begins with a two-day site visit by the EPRI team to evaluate the plant’s existing lubrication program. Plant observations are made and personnel interviews are conducted to evaluate and assess existing lube oil practices. Each key element or area is assessed. In practice, the observations are conducted in a manner that mimics the path of a lubricant as it travels through the facility. Typically, the auditors begin in the storeroom receiving area, to observe the manner in which lubricant shipments are received and initially stored. Interviews with storeroom personnel help to provide an overall picture of the plant’s current practices. The oil path is then tracked to its central storage location, plant distribution centers, transfer containers, the machines themselves, and finally, to disposal. Sampling points, the sampling process, and the analysis process are also addressed as part of the audit process. Throughout this cycle, key personnel are surveyed, including those who handle the lubricants or take actions to impact lubricant quality (through storage, transfer, and sampling), and those who are involved with lubricant analysis. Typically, these personnel would include: •

Purchasing agents

•

Storeroom receiving personnel

•

Storeroom issuing personnel

•

Supervisors responsible for central or satellite lubricant storage

•

Individuals involved in transporting lubricants to and from storage locations

•

Machine operators and others involved in topping off lubricants at machines

•

Maintenance personnel involved in filling reservoirs during maintenance

•

Maintenance personnel or operators responsible for filter monitoring and changing

•

Lubricant sampling technicians

•

Oil analysis technicians

•

Oil analysis/lubrication program owner

•

Predictive maintenance program champion—performance level

•

Predictive maintenance program champion—management level (who sponsors the program)

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Typically, each interview takes about 15–30 minutes, depending on the interviewee’s level of involvement in the program. It is requested that a site contact, preferably the Lube Oil Program Owner, be present and participate in the audit process. An exit interview is conducted with the management team prior to the EPRI team’s departure. The audit process evaluates the lubrication program by reviewing the existing activities within each key element. Each element of the lubrication program is rated on a one-to-ten scale. The purpose is to generate a graphic representation of the status of the existing program. A score of 7 or 8 is very good. A score of 4 or less indicates that real improvement is needed. A score of 10 is considered a top decile world-class performer, whose standards require the support and efforts of an engaged management and craft team. However, an 8 or above is referred to as being World Class. The results are graphically depicted in a radar or Spider Chart as shown in Figure 1-1.

Figure 1-1 Lube Oil Audit Spider Chart

Audit Report The next step of the audit process is the development and presentation of a comprehensive audit report containing key audit findings and focused recommendations for improvement. An executive summary is provided with immediate impact and the prioritized next steps that should be taken. Each finding is addressed including focused recommendations and, where applicable, best practice information links. A typical report input of sampling techniques is shown in Table 1-1.

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EPRI Licensed Material Introduction and Overview Table 1-1 Sampling Techniques Equipment/Area/Item

Finding

Recommendation

Note/Image Reference – Sampling Port Location General Discussion.doc

General oil sampling

Very few locations for obtaining representative online samples were seen. An overall assessment of the sampling program should be performed.

Review the examples given of proper sampling point locations and perform an evaluation of all analyzed equipment to determine proper sampling technique and location.

Vertical motors 480V/4kV

No appropriate sampling location currently provided.

Install oil sampling fitting at the location indicated by red arrow by installing into existing thread with a short busing, referencing the oil sampling procedure.

Sampling Procedure – Probe-On Vacuum.doc

Implementation Plan In most cases, best practices are included as part of each recommendation for improvement. An Implementation Plan is then developed that includes action items, areas of responsibility, and an overall program implementation schedule. Implementation Plan Development After the report has been reviewed, a detailed Implementation Plan is developed using an Action Item Matrix as shown in Figure 1-2. The Action Item Matrix captures each action item and responsibility assigned to ensure that each recommendation is properly addressed. As shown in Figure 1-3, the overall Implementation Plan is developed to track the progress of the action items.

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Figure 1-2 Action Item Matrix

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Figure 1-3 Microsoft Project Schedule – Implementation Plan

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Technical Assistance and Follow-Up Audit As part of the audit process, technical assistance is provided to help implement the audit recommendations. A follow-up effectiveness audit is also conducted and a report is produced to evaluate the progress of the lubrication program.

Lube Oil PdM, Handling, and Quality Assurance Guideline Report The experiences gained through the development of this lubrication program, and the information and best practices obtained through the continuing lubrication audits, have been captured in this Lube Oil Predictive Maintenance, Handling, and Quality Assurance Guideline. Lubrication audits are still being performed and additional best practices will be captured for inclusion in an addendum to this guideline. It is also the future intent to capture the process of performing self-audits and to identify true industry standards for rating each key element based on actual industry data. Each of the following sections of this guideline is based on a key element of the lubrication program. Each section discusses specific areas within that element that should be addressed when implementing or improving a comprehensive lubrication management and analysis program. Best practices have also been provided where applicable.

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2

STANDARDS, CONSOLIDATION, AND PROCUREMENT

The first step in the cycle of using lubricants is the specification, purchase, and receipt of new lubricants. The basis of effective lubrication is the right product, in the right location, at the right time, in the right condition, in the right amount. Using the right product starts with its specification and purchase. Often, this function happens independent of those individuals who might be considered as the lubrication experts for the site. As a result, sometimes the sole criterion for the purchase of lubricants becomes cost. Lubricants that are purchased based solely on cost, without consideration given to the technical requirements, the quality implications, or the effects of interchangeability of lubricants, can have a significant adverse effect on the lubrication program. At any given time, the currently stocked lubricants for a facility typically include the products originally specified when the plant or machinery was designed, plus any number of additional products that have been added over time. This population of products may or may not be an efficient allocation of the proper type and number of different lubricants in use. Making the process even more difficult is the fact that many equipment manuals, which are provided as a guideline to installation and maintenance of that equipment, are rather vague in their description of lubrication requirements. For example, it is not uncommon to find an equipment manual that will specify something such as “use a good grade of mineral oil 300 SSU.” Another possible recommendation could be from a manufacturer to use the specially named product that they supply with their equipment or an equivalent. That named product might be merely a repackaging of an existing manufactured lubricant, which is then resold at a greater price to the customer. Although manufacturers are required by law to supply their customers under warranty with either alternate lubricants that they can use or a free supply of their own solely specified lubricant, many times the information given about alternate acceptable products is minimal and leaves much to be desired. Plants that have an efficient system of procuring lubricants typically have performed a lubrication consolidation in the recent past. The consolidation process is most effective when implemented with strict configuration controls in place. These controls are typically in the form of guiding procedures that limit how new lubricant types can be specified and that provide for a periodic review of lubricants in use. The approval process for new lubricants is linked to a set of existing generic specifications that have been created to address all of the equipment lubrication needs for the site. A receipt inspection program has also been implemented that provides for the quality assurance of delivered lubricants, whether packaged or in bulk. Nuclear power plants have also identified all equipment whose lubricants must be purchased Q-class, and have taken steps to ensure that non-Q supplies of the same product cannot mistakenly be used in those applications.

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EPRI Licensed Material Standards, Consolidation, and Procurement

Consolidation—Optimizing the Use of Lubricant Products To understand the need for consolidation present in most facilities, it is important to realize just how lubricants become specified for machinery. In most cases, plants are built around an optimal design for production of the desired product. This can mean that a given facility can have a wide range of components from many different suppliers and equipment manufacturers. Manufacturers supply information about lubrication requirements with their equipment, but the specificity of those recommendations can vary greatly. Although some equipment manuals may include detailed instructions for specifying and selecting a suitable lubricant, others may be extremely brief and vague. Statements such as, “use a good grade of 30 weight mineral oil,” may be the sole direction in choosing the lubricant. It is with this varied and uncoordinated set of guidelines that design and construction engineers select lubricants for plant equipment and stock quantities of the needed types in the facility. Even when efforts are made during this phase to minimize the number of products, changes to the plant over time can lead to additional lubricants being used in new or upgraded equipment. When performance problems are experienced with equipment, it is not uncommon for personnel to arrive at a conclusion that the current lubricant was the cause of failure and to specify a new product to be used in that application. Over time, these changes can lead to a growth in the number of products inventoried and used in plant equipment. Figure 2-1 shows the types of lubricants recommended by various suppliers and the variations that depend on plant-specific requirements.

Figure 2-1 Suppliers’ Recommendations

Business competitiveness and lean manufacturing techniques have, in recent years, led to the scrutiny of many of the costs of operating a facility. Not least among these are costs associated with maintaining an inventory of equipment, parts, and supplies for production machinery. This has inevitably led to the assessment of lubricant types and brands in a facility storeroom and a general acknowledgement of the need to reduce. But unlike discrete parts, which are assigned to 2-2


specific equipment applications and can be addressed through a review of consumption frequencies and just-in-time scheduling techniques, lubricants are more like a commodity. The uses and requirements are not as clearly defined and it takes more care to ensure that, when changing any of the products used in lubricating equipment, the proper product is specified for the equipment type, application, and environment. From this starting point, significant gains can be made through a careful evaluation of the products available and the equipment needs. Even a general review of existing inventories can reveal potential savings merely through the identification of redundant products from different manufacturers. The chart in Figure 2-1 illustrates how a given plant may identify the distribution of lubricant types among a number of different suppliers when first glancing at an existing inventory. When a varied number of suppliers exist, there is probably the potential for making initial gains in consolidation, solely through the evaluation of product data sheets for the lubricants currently in use. A carefully planned approach to lubricant consolidation can translate into big benefits. The keys to success are identifying all lubricants in use, using equipment lubricant requirements to create generic specifications, and adopting an environment of continuous improvement through the use of a current and updateable database. A multi-phase approach can allow a facility to realize real benefits after a minimal investment and allow sufficient support to be generated to sustain the effort. As the program grows, multiple facilities within a given company can be brought together to share data and leverage lubricant buying power. Using existing database resources of commercial lubricant properties, equipment lubrication requirements, and lubricant equivalency tables will result in the lowest cost optimized lubrication program. Determining the Consolidation Approach When taking a first cut at consolidating lubricants, many companies find that the most economical way to proceed is to use the incentive of increased lubricant sales to entice a lubricant supplier to provide the service for reduced cost, or possibly at no cost. Many suppliers, especially the larger companies, use this as a marketing tool to increase their sales. Larger endusers are offered free lubrication engineering service and this opportunity typically results in a consolidation of the existing slate of suppliers to a very few. Optimally, all existing products are cross-referenced to the assisting suppliers’ products. Some will go beyond the simple crossreference and actually tour the facility to look at equipment to help make the determination. This type of consolidation can be very effective, especially for companies with a large existing inventory of lubricants from a large variety of suppliers. Additionally, the out-of-pocket costs can be close to zero, which is always well received by managers trying to get as much as they can out of their budget. Real costs, however, are higher and include the time invested by plant personnel to interface with the supplier lubrication engineer, the cost of replacing the existing lubricants with the new supplier’s products, and the costs associated with revising procedures, labels, and other documentation to indicate the new products. Another positive is that most suppliers offering this service generally furnish lubrication engineers with considerable experience and knowledge, which sometimes exceeds the expertise level of plant personnel. As some have said, “it’s like getting a lubrication expert for free.” 2-3


However, with even the most reputable suppliers, there are trade-offs for this “free” service. For one, it is intrinsic in the fact that these companies are in the business of selling oil, that there may not be an incentive for them to help the plant reduce lubricant consumption. Indeed, the potential to sell more product is the very incentive that has them offering the service. Although the total number of suppliers will invariably be reduced, there is some question whether the total number of different products will be reduced. Again, there is little to drive the supplier to reduce the number of different products. Another byproduct of using a supplier to perform the consolidation is the removal of product price reduction pressure in the absence of competition. Once a company has cleared out its storeroom, brought in the new product, changed out their machines, revised procedures and changed labels; it would be difficult to justify doing it all over again to respond to a different supplier who may offer similar products at a lower cost. The supplier’s knowledge of this may remove some of their incentive to keep product costs competitive. In spite of the concerns listed here, lubricant supplier-provided consolidation services can still be a useful and viable option for companies to consider when approaching a lubricant consolidation project. A general rule of thumb may be that, if less than 50% of the total number of products is provided by any one supplier, then a lubricant consolidation proposal provided by a potential supplier can be a valuable first step in optimizing a facility’s lubrication. A party that holds no interest in the sale of products to the company generally provides an independent evaluation to the organization. This service appears to be more costly because the company now pays the full cost of the engineering service directly to the provider, instead of indirectly through the cost of the lubricants it purchases. There is an obvious and direct impact on the company’s budget and this can serve as a barrier to selecting this path. The exception to this is when plant staff or corporate personnel provide the service. In that case, the costs can be quite high but are hidden because the salaries of those individuals are being paid whether they are working on lubrication or some other function. In an independent optimization, however, the entire approach to lubricant consolidation is changed. Instead of focusing on the existing products in use and finding equivalents, the focus is on optimizing the lubricant inventory based on equipment design, production, and environmental needs. This method is a three-phase process to identify redundant products, define equipment requirements, and develop lubrication specifications. Phase I—Brand Consolidation Somewhat like the efforts undertaken by lubricant suppliers performing consolidation, the first step of independent optimization is an inspection of existing lubricants and a comparison of product design and application. Although some of this consolidation can be done by inspection based on personal knowledge of the products, the majority of the work is accomplished by obtaining the technical data sheets for all of the products on the list. This is not as easy as it sounds. Some manufacturers openly share the physical/chemical property and performance data for their products, but others closely guard this information.

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Many suppliers include these data on their web sites or graciously fax or email the data sheets upon request. Others may present more of a problem. As a customer, it is usually possible to get this information from the manufacturer without too many problems. There are some suppliers, however, who may refuse to release this information. It is necessary at that point to determine if the product is sufficiently unique or of such superior performance to warrant its continued use, because it will be impossible to include it in the consolidation effort. Figure 2-2 shows a typical table used to compile a list of currently used lubricants, including identification of each product by application and type. Designations include Extreme Pressure (EP) Gear Oil, Turbine Oil, R&O Oil, Worm Gear Oil, and Anti-Wear (AW) Grease. Within the greases, thickener type is also used to identify the product, because some applications require specific thickener types. Once this has been done, products are grouped together by type to indicate where there may be redundant product types from different manufacturers. The total number of groupings is the total number of different lubricant types currently in use. Many times this first step, although requiring minimal work, can identify significant opportunity for elimination of redundant products. As much as 40% of a given plant’s inventory may be eliminated in this manner.

Figure 2-2 Typical Lubricant Table

A table similar to that shown in Figure 2-3 can be developed to identify the functional properties of the lubricants and the overlaps. Once the lubricants have been grouped together, the decision to reduce certain products can be based on operating experience with the products, ease of storage or purchase, or, most likely, unit cost. Once the surviving product is identified in each group, the others can be phased out by not restocking the redundant products. It is important to confirm compatibility between manufacturers within a group. If an incompatibility exists, processes must be put in place to ensure that one product is not topped off with another when the product being replaced runs out. In that case, a reservoir flush must preceed the changeover.

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Figure 2-3 Lubricant Identification

Phase II—Technical Consolidation Although the brand consolidation can be very effective, it doesn’t ensure that the products being used presently are right for the job. Somewhere along the line, an improper product may have been specified or equipment may have been modified without addressing the changed requirements of the lubricant. To ensure that lubrication is optimized (that is, that all equipment has the proper type and amount of lubricant specified), it is necessary to go further. The next step of the process expands the investigation to the equipment and component level. By reviewing the population of lubricated equipment in the facility and identifying the make and model, vendor specifications can be obtained. It is important to remember that lubrication is a fundamental design property and the machine designer makes certain assumptions and design decisions based on the lubricant to be used. It is, therefore, important to begin any technical evaluation by looking at the recommendations made by the equipment designer, captured in the vendor manual for the equipment. Assembling the list of all lubricated equipment in the facility is the first step. This is often accomplished by using existing databases, such as the Computerized Maintenance Management System (CMMS), the lubrication route, or a predictive maintenance database. Using a versatile program like Access® or Excel® allows flexibility in the design and output of the database. Figures 2-4, 2-5, and 2-6 show typical screens from a database developed in Access. After converting the raw data to the database format, fields are established for equipment ID, reservoir ID (for multiple sump equipment), manufacturer, model number, and current lubricant. For equipment that is assembled from separate manufacturer’s components (such as a Roots blower driven by a Siemens motor) and provided with separate vendor manuals, it is necessary to treat them as separate database entries.

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Figure 2-4 Screen from Access Database


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The next step usually takes place in the plant library or at another location where most of the vendor manuals can be found. Not all facilities have done a good job at cataloging equipment vendor manuals, so some extra work is usually required in researching the manufacturers to obtain the lubrication design data. When using outside service providers, there may be some advantages at this stage because they may already have a catalog of equipment lubrication design data from previous consolidation efforts. Other fields in the database are used to identify the key physical/chemical properties and performance characteristics. Figure 2-3 showed how the lubricants can be characterized by these properties. A similar table is used to identify the equipment requirements. A project can be brought to completion in this step by using these tables to find the overlap between available products and equipment requirements. The most significant gains are made, however, when proceeding to the final step and creating the blueprint for lubricant optimization: generic specifications. Phase III—Generic Specifications Once the lubrication requirements have been determined for the facility, that information can be reduced to generic purchase specifications. This optimized configuration can be used to meet the lubrication requirements for the facility, and then these specifications can be taken to the potential lubricant suppliers to obtain the benefits of leveraged purchasing power. This allows the plant to obtain the best deal on those products whose characteristics and performance meet or exceed the minimum standards outlined in the specifications. This also provides for the flexibility of using multiple suppliers or changing a particular supplier from time to time as product prices, quality, or availability vary. Of course, to ensure the compatibility of products from different suppliers, care must be taken when changing suppliers and products. A list of lubricant application types can be developed for the facility using the tables or databases that have been constructed for equipment lubricant requirements, operating conditions, and 2-8


environmental conditions. Examples include EP Gear Oil, Turbine Oil, Anti-Wear Hydraulic Oil, Worm Gear Oil, and Hi-Temp Grease. Within each of these application types, the viscosity grades necessary to address machine requirements can be identified. The process generally proceeds by choosing some obvious category classifications within the population of identified required product types, and then by creating generic specifications for those types. Plant equipment is identified in the database as belonging to a generic specification. As generic specifications are assigned to the database, those machines are filtered out of the population requiring specifications. Before creating new specifications, the existing set of specifications is reviewed to see if any of them meet the requirements of the next machine. In those cases where the difference in requirements is minor, consideration is given to expanding an existing specification to include this next piece of equipment, or possibly going to a multi-purpose lubricant or taking advantage of the properties of some superior performance product types (such as synthetics). The goal is to determine the minimum number of unique lube application types that will address all equipment needs within the plant. The specification must be sufficiently generic to be able to receive competitive bids for products that will meet the specification. In efforts to minimize the number of application types, care must be taken to avoid overlooking any critical performance characteristics of the lubricants. There is such a thing as “over-consolidation,” where too much focus is placed on limiting the number of different products being stocked, at the expense of lubricant performance. It must be stressed that just a few or perhaps one lubricant-induced equipment failure can wipe out all of the potential monetary savings of a consolidation project. Wherever possible, the specification reference must recognize standards such as those of the American Society for Testing and Materials (ASTM) and the American Gear Manufacturer’s Association (AGMA) when developing the chemical/physical and performance characteristics. A simple and standard format presents both the acceptable testing result limits, and a discussion of general application usage and lubricant properties. Figures 2-7 and 2-8, located on the following pages, show the front and back of a typical generic lube specification. The generic specification consists of two pages of information that can be printed back-to-back to have a single sheet. This is intended to serve as a reference document, which a purchasing agent can use to properly solicit bids for required products based on the facility’s consumption of that type of lubricant. The first page consists of a product description, a description of the applications for this product, and an overview of the specifications. The specification description includes packaging and labeling requirements, cleanliness considerations, and equipment- and environment-specific considerations. The second page of the specification is a tabular compilation of the physical/chemical and performance characteristic requirements. Values are given for the required range of viscosity grades for oils, base oil viscosity, NLGI grade, and thickener type (for greases).

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Figure 2-7 Typical Generic Lubrication Specification

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Figure 2-8 Typical Generic Lubrication Specification

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Using a Database for Continuous Improvement In the same way that the addition of new equipment or changes to the facility were originally described as one of the needs for consolidation, the work is still not considered complete just because the consolidation is finished. Procedures and processes must be in place to control and update the inventory of lubricants and their assigned equipment to take changes into account. The most efficient way to accomplish this is to produce a database that will serve as a living document of lubricant inventory and application. The construction of the database is not a large amount of additional work because all of the information needed was compiled during the brand and technical consolidations. The database can serve as an ultimate reference source for equipment lubricant requirements, and can be integrated with an electronic lubrication manual to provide a single source of equipment-specific lubricant information for the facility. The previously illustrated Figure 2-4 shows a typical start screen for a database (such as the one described) that could be developed for a multi-plant company. By making the database accessible to the company intranet, further efficiencies could be developed in the use of lubricants at different sites. This start screen provides selections for each of the individual plants, thus allowing users to narrow the information search to their facility. Reports can also be generated that query from the larger database and allow information to be extracted from across the sites. Once a site has been selected, options can include editing and recording data (as seen in Figure 2-5). To minimize the occurrence of data corruption, the add/edit function can be limited to only authorized personnel. Various reports can be generated, or customized queries can be made based on the information desired by the user. The data entry mode screens, such as that seen in Figure 2-6, allow the user to enter new records or modify existing records to reflect changes. These changes could include the addition of new equipment, a replacement part from a different component that requires a different lubricant, or feedback from Proactive Maintenance (PAM) investigations that result in design changes to the equipment lubrication. Once this resource, used to track the development of the optimized lubrication configuration for the facility, has been created, a functional database exists and can be used as a living program to incorporate feedback from operational and maintenance experiences and the changes in lubrication management that it prompts. It is also possible to scale up and apply corporate-wide what has been done on a facility level. The single greatest pitfall to the successful implementation of a lubrication consolidation is a lack of configuration control after the original project is complete. Adopting the living program, through the creation and maintenance of a database and the development of policies and procedures that define responsibilities for program improvement, will enable an environment of continued lubrication excellence.

Quality Assurance and Receipt Inspection Procedures should be in place that provide for the immediate acceptance of delivered drums, totes, and containers, and their movement to a designated storage location for processing. Without such controls in place, there is a risk that containers are left exposed to contaminants for some period of time before being processed (Figure 2-9). Oil drums exposed to the elements are subject to temperature extremes, direct sun, and rain that will compromise lubricant quality.

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Figure 2-9 Source of Contamination

A designated room or enclosed structure is needed to store lubricants. The room or structure must be climate controlled, have limited access, and have appropriate fire suppression and spill response equipment. They should be stored neatly to minimize confusion and the possibility of taking the wrong product. The acceptance storage area should be clean, dry, and provided with necessary fire-protection measures (Figure 2-10).

Figure 2-10 Appropriate Storage Area

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A documented procedure is necessary for receiving and inspecting new lubricant deliveries, including acceptance criteria. This should include an agreement with local lubricant distributors regarding their role in optimizing lubricant storage and handling practices. Their responsibilities should include the occasional reconditioning of containers. All lube containers should be date-stamped with the following information: date of blending, date of receipt by the plant, and date opened and put into service. The date-opened information recorded on the drum will allow the proper shelf life limitations to be applied. Packaging materials should protect the oil from handling and shipping hazards, including ingression of contaminants, moisture, and debris. Packaging material should be inert to the product oil and conform to all applicable shipping rules and regulations. Packages should be plainly marked with the manufacturer’s name, oil brand name, product code, lot number, type of material, volume content, and any other information required by law. The condition of the containers should be checked, including any damage, signs of neglect, signs of outdoor storage (faded labels, etc.), or any leaks. Any container leaks will also be subject to contaminant ingression and will compromise the lubricant supply quality. Leaking containers (Figure 2-11) should be immediately returned to the supplier.

Figure 2-11 Leaking Container

Testing Sampling and analysis of newly delivered containers and bulk shipments should be part of a commodity quality assurance program. In particular, the cleanliness of delivered lubricants varies greatly and can contribute significantly to the level of contaminants that end up in lubricated equipment. By testing lubricants on a batch basis at the time of delivery, the integrity of the lubricant supply can be improved.

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Sampling methods employed should be consistent with sampling best practices as detailed in Section 4 (Sampling Techniques). Sampling lubricants in new containers or from bulk shipments can be challenging but it is important that the samples obtained are representative of the entire container. Batch testing for items that are purchased in lots is a cost-effective way of minimizing the amount of samples required. A testing slate should be developed that reflects the key characteristics of the lubricant and the likely contaminants that should be screened. Greases should be tested for their specific key properties as well, including consistency and dropping point. In some cases, supplier-provided documentation can take the place of required receipt testing, provided that the supplier’s manufacturing and testing programs have been audited to ensure that sufficient Quality Assurance (QA) programs are in place. Examples of this include the acceptance of supplier lubricant testing data for those manufacturers that have undergone Nuclear Procurement Issues Committee (NUPIC) audits for the nuclear power industry. Quarantine When certain lubricants have been identified as requiring acceptance testing prior to deployment to the plant, there should be an established quarantine area for holding those containers until the testing can be completed. Access to this area should be limited to prevent the inadvertent use of lubricants that have not been cleared for use (Figure 2-12).

Figure 2-12 Establish Quarantine Area

An additional step that should be taken following the sampling for acceptance testing is the positive re-closure of the container. Some lubrication audits have shown that drums that have been opened for the purpose of sampling and analysis have subsequently had their quality compromised by their opened bungs. By resealing drum bungs and ensuring positive re-closing 2-15


of other containers, the results of such acceptance testing will be truly representative of the condition of the lubricant in that container. Figure 2-13 shows a drum re-closer tool and caps. These caps can even be customized to indicate that a drum has been sampled and is awaiting testing, or has been sampled and approved for use. Self-gasketing cap seals crimp over drum plugs. Once crimped in place, they indicate unauthorized entry into the drum because the cap seal must be destroyed to be removed.

Figure 2-13 Drum Re-Closure Tap and Caps

Q-Class Lubricants for Nuclear Power In the late 1980s, Mobil Oil instituted a program to produce a product line of lubricants that could be purchased as Safety-Class with the necessary provided documentation. The increased cost of these lubricants caused many plants to adopt a strategy of performing commercial-grade dedication of off-the-shelf lubricants that met the design criteria for their safety-class lubricated components. This was deemed to be an acceptable practice, and soon Mobil discontinued the production of the MobilRad products. It is important for nuclear power plants to commit to providing Q purchase-class lubricants through a commercial-grade dedication process wherever necessary in their facility. Commercial-grade dedication packages must exist for these products, and a clear plan should be in place to prevent a non-Q lubricant from being used in a Q application. Most facilities have accomplished this by commercially dedicating all stocks of a given product that have at least one Q-class application on-site. Others maintain both Q and non-Q stocks of a given product but assign separate stock codes for use in the different machines. This is a riskier approach and must be accompanied by strict adherence to procedures, which ensures that lubricant technicians are obtaining lubricants for Q equipment directly from a clearly labeled, dedicated Q-class product.

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3

STORAGE AND HANDLING

The bulk storage and dispensing of lubricants, and the topping off and filling of machine reservoirs, are areas fraught with opportunities for mixing of lubricants and lubricant contamination. Great care and consideration must be given in assigning areas for the storage of lubricants, and to the containers that are used to transfer lubricants to machine reservoirs. As an example, even though the drums (shown in Figure 3-1) have been properly blocked, the longterm outdoor storage has rusted the containers and likely compromised the quality of the lubricant.

Figure 3-1 Potential Contamination from Outdoor Storage

Generally speaking, there will be an assigned storage area for all new drums, totes, pails, canisters, tubes, and other units of purchased lubricants that will typically be found in a storeroom area. When assessing the storeroom storage areas for lubricants, it is necessary to look at a couple of things. First, have storeroom personnel established shelf lives for the lubricants and, secondly, do they practice FIFO (First In First Out) rotation of lubricants? The manner in which the lubricants are stored may or may not be conducive to FIFO inventory rotation. One good practice, which ensures the FIFO process, is to have an area where incoming lubricants are issued in and stored, and another area or the other side where outgoing lubricants are issued. This creates a natural FIFO progression of optimum usage as illustrated in Figure 3-2. The lubricants should always be stored indoors, segregated from other chemicals and storage materials, and in a lay down area that is kept clean and free of debris, dust, and dirt. 3-1

EPRI Licensed Material Storage and Handling

Figure 3-2 Correct Progression of Usage

Because lubricants are combustible, this area should also be provided with appropriate fire safety equipment, such as a sprinkler system and easily accessible fire extinguishers of the right type for fighting a liquid petroleum fire. The possibility of puncturing containers during handling, and the resulting leakage, makes it a good practice to have spill clean-up materials in the area where lubricants are stored and, where possible, an erected berm to prevent a loss of spilled materials into surrounding storm grates and other unacceptable areas. Drums and pails should not be stacked on top of each other because of the likelihood of floor dirt from the bottom of one container being transferred to the top, or pouring surface, of the other container. Also, the likelihood of damage to the containers is greater when they are stacked. All containers in such a storage area should be clearly labeled with the product name, lot number, shelf life expiration date, and any chemical control handling information that is necessary. Like lubricants should be grouped and these areas should be labeled to minimize the possibility of the incorrect product being issued from the storeroom. Under the topic of storage and handling is also the treatment of bearings, seals, and gears. Although they are not lubricants themselves, the ultimate reliability of the lubricated machinery is dependent upon the cleanliness practices throughout machine life, including storage of its constituent parts as shown in Figure 3-3. Dirty or damaged bearings, seals, and gears will still contribute to premature failure even when all other lubrication practices are sound. Therefore, bearings, bearing housing seals, pump seals, and gearboxes must be carefully stored to avoid unnecessary and unacceptable contamination while in the storeroom. Machines that are stored for long periods of time must be stored with the reservoirs filled, and they should be periodically rotated to fully coat the parts, thus providing corrosion protection. Rotating element bearings, whether they are stored singly in their box or are installed in a machine assembly, must be cared for so that ambient vibration does not introduce False Brinnell marks that would lead to a rapid and premature failure of the bearing. In a best practice scenario, bearings are stored in a segregated area in a cabinet that protects them from ambient dirt and dust. The cabinet is positioned on rubber mats to absorb any ambient vibrations that may be transmitted to the bearings.

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Figure 3-3 Storage of Parts in a “Clean Room”

In the storeroom, education plays a role as well. It is important to determine if the individuals who are charged with dispensing lubricant containers, storing them for extended periods of time, and for handling and distributing bearings, gears, and seals are educated about the importance and impact of improper handling on lubricants and lubricating components. Storeroom employees need to realize their impact on machinery life. If an individual drops a bearing on the way from the storage shelf to the issue counter, yet doesn’t recognize the fact that they have just damaged the bearing by Brinnelling, they are likely to issue a part that is ultimately doomed to premature failure. Receipt inspection by storeroom personnel is a significant quality step in ensuring that proper lubricants are being supplied to the plant. The receipt inspection process includes analysis of the containers for product integrity, proper labeling of the containers to ensure that the product that has been purchased does meet the intended properties and qualities, and acceptance testing through sampling and analysis of a portion of the population of incoming lubricants. For the lubricants that are sampled for acceptance testing, it is also imperative that the integrity of the container be maintained after it has been opened to obtain the sample. There must be appropriate procedures in place and tools available to obtain a representative sample from the drum, tote, pail, or other container that is being sampled. There must be a clear methodology in place that controls the opened containers to prevent any change in the cleanliness or make-up of the container after the seal has been broken, and some mechanism or tools must be available to adequately reseal the container and ensure its integrity. A typical drum-sealing tool is pictured in Figure 3-4.

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Figure 3-4 Drum Resealing Tool

Once lubricants have been distributed from the storeroom issue point, they are then typically taken to a central or satellite lubricant dispensing location. This area, or areas, is generally centrally located within the plant to enable ease of access for those individuals involved in the lubrication/relubrication process. The number of satellite storage locations should be minimized to make it more practical to control the access to, the use of, and the maintenance of these areas. Wherever possible, a single central lubricant storage and dispensing site should be established. This area will be accessible only to those individuals who are routinely involved in the distribution and transfer of lubricants, and who have been properly trained in the handling and care of lubricants and lubrication equipment. Most lubrication dispensing facilities will use either a drum dispensing station or dedicated lubricant storage containers that are filled from drums, bulk storage, or totes (Figure 3-5). Whether using the drum dispensing racks or the dedicated lubricant reservoirs, there must be provisions for properly ventilating the containers. Other provisions include filtering the fluid upon filling or dispensing, proper and clear labeling of the product in the containers, the ability to dispense lubricants without the possibility of cross-contaminating fluids, and other measures to prevent spillage, static discharge explosions, and other safety concerns. The room itself should be fitted with fire suppression sprinklers and fire extinguishers, which are maintained and are of the proper type for fighting liquid petroleum fires. When drum racks are used, it is necessary to have a lifting mechanism in place so that the drums can be safely placed in the proper orientation (whether horizontal or vertical) and raised to the proper height in the rack. If drums are to remain on the floor in a vertical position, they should have clearly marked lay-down areas that are labeled and easily accessible without cluttering the area or impeding access. 3-4


Figure 3-5 Central Dedicated Storage Reservoirs

Lubricant storage areas must be assigned to a responsible individual or owner. This individual is not only responsible for the housekeeping of this area, but is also tasked with maintaining necessary lubricant inventory. They should verify that spill clean-up kits are stocked, Material Safety Data Sheets (MSDSs) are available, and that any disposable drums are emptied as needed. All fire and other safety protection equipment should be verified to be in proper operating condition. To minimize the opportunity for contamination or the use of improper products in place of the lubricants, storage areas should not be used for dual purposes, such as for the storage of other chemicals or flammable materials. Within the lubricant storage and dispensing area, there should be a cabinet or shelf dedicated to holding transfer containers such as is shown in Figure 3-6.

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Figure 3-6 Storage Locker

The transfer containers should be specifically designed for the purpose of transferring lubricants from bulk storage drums or totes to the machinery. The design should include such features as an easy pouring spout that eliminates the need for the use of funnels, a spout closure or dust cap to prevent contaminants from entering, and a covered fill opening or vent area to prevent dirt from entering the container (Figure 3-7). Transfer containers should also be part of a routine sampling program to prevent and identify instances of mixing lubricants, contamination of lubricants, or aging of lubricants in the transfer container. This analysis program can be initiated simply by adding identification designations to each transfer container, and including these in the list of equipment that is subject to periodic sampling. When oil sampling schedules are generated, they will include, on a periodic basis, the transfer containers stored in the lube oil storage and dispensing area. A preventive maintenance (PM) activity should also be developed for periodic cleaning and/or replacement of oil transfer containers to address any accumulation of contaminants or aged oil in the transfer containers.

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Figure 3-7 Transfer Containers

An alternative best practice to the use of oil transfer containers is the use of sealed batch containers, which are smaller quantity, single-use, one-shot containers. These one-shot containers are pre-filtered, filled, and sealed with the proper lubricant and labeled as such. They are created in quantities that will closely match the needed top-off quantities for a given route. This gives the lubrication technician the ability to pull a single one-shot container for a given route, use it, and dispose of it. This greatly minimizes the opportunity for the mixing of lubricants and/or contamination, which can sometimes occur in the use of reusable transfer containers. The trade-off in this case is that, generally speaking, it is difficult to match the exact quantity in the one-shot container to the quantities needed for a given route or activity. There is typically some lubricant left over that ends up being disposed. The use of inadequate transfer containers is perhaps the most common problem discovered in the audit of lubrication programs. Anything from leftover chemical storage containers to old coffee cans have been discovered as the primary method for topping off costly and critical plant equipment. In many cases, major improvement can be made to equipment performance and reliability just by gaining control over the types of transfer containers used, and the practices used in re-lubricating equipment. Another area of concern in lube oil storage and dispensing is the disposal of oil soaked rags and used lubricants. Oil soaked rags should be stored in appropriate combustible containers that address the fire safety concerns present in the plant regarding accumulation of oily rags. They should be disposed of in a systematic and procedurally defined manner that ensures their safe disposition. The disposal of lubricants oftentimes involves using containers that are stored in the lube oil dispensing and storage room. Although this in itself is not necessarily a poor practice, it raises concerns about the possibility of used lubricants being mistakenly used as new lubricants. To avoid this, any disposal drum must be clearly and accurately identified as for the disposal of used lubricants only.

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When a used lube oil disposal container has been filled, there must be clear responsibility for monitoring the level as it approaches the fill point on the container. The container must be sealed and clearly marked to prevent it from being mistakenly used as a new lubricant. It must be promptly removed from the area and disposed of in accordance with all safety and environmental requirements. In the storeroom, it is also important to consider the amount of space needed, the furniture and benches, provisions for storage, lighting, power, and ventilation, and, above all, to ensure the ergonomics of it all. Making the work area and procedures as simple and as painless as possible will encourage ownership and enthusiasm in the room, which ensures that proper lubrication is achieved. Because several people may be involved in the storeroom, consistency in the procedures and housekeeping is critical to good management. Each person is essential to the overall success of the storeroom’s design. It is, therefore, imperative that the work area be laid out properly and, to avoid unwittingly contaminating stock, that good housekeeping is practiced at all times. The storeroom will be a showcase, the hub of an efficient operation, if successful, and should look presentable at all times. An adequate storage area for lubricants, lubrication equipment, and supplies is necessary. For some, this may simply be an appropriate cabinet or locker; for others, it may be bulk storage with pumped dispensing systems. What is common to both is the need to ensure the basics of avoiding outdoor storage, providing adequate racking for the containers, providing suitable handling and dispensing systems, as well as disposal arrangements. More important is the need to comply with Health and Safety regulations and ensure that all members of the staff are trained in fire-fighting and spillage procedures.

Health, Safety, and Environmental Issues The work area is critical to the smooth operation of the service. The comfort of the lubrication technician is important because of the somewhat hazardous nature of the room and the job. Giving ownership to the individual will help develop interest in the job at hand. This may involve having the individual play an active role in the design and functionality of the area. Apart from the comfort of the lubrication technician, it is also important that the storeroom is maintained at a constant room temperature with adequate ventilation. Ventilation is important to avoid the build-up of dangerous fumes that pose a fire and health risk. Ensuring maximum shelf life of the lubricants is equally as important. The room should be dry to avoid contaminating the oil with the ingress of moisture. It is necessary to request an MSDS for each lubricant to keep in the storeroom for quick reference and, more importantly, for the lubrication technician to check before handling the lubricant. The ergonomics of the physical layout should be considered. Because each operation has unique circumstances with respect to lubricant types and consumption, ergonomics will be achieved over time and improvements can be made along the way. In addition to the obvious shelving or racking for the storage of containers, there should be a workbench with sufficient surface to

3-8


allow for dispensing and handling tools. Power points should be provided for any power tools or filter carts and, in some instances, an air supply line might be required. Obviously, warning signs are necessary to communicate the danger of the fluids in these containers; smoking and eating should be prohibited in this area. Non-slip flooring should be installed for safety reasons. This will allow for easy clean up and is impenetrable to oil spillage. A concrete floor looks unsightly after a short period, is difficult to keep clean, and could contribute to airborne contaminant. Likewise, the walls should be painted or tiled to minimize cleaning and dust release. Space for the disposal of used oils must be considered, whether storing them for removal by a contractor or for reclamation or burning on-site. It is also important to consider any drains that may run under or near the oil room because a spill could possibly contaminate local water sources. This may require special drainage within the room. Special containment sacks should be available at all times to prevent a spillage from seeping into drains and should be placed not just in the storeroom but around the site. Signs, labels, and tags on the containers and piping used to dispense oil should be adequately descriptive and well placed. Any individual working with lubricant storage and distribution systems should be familiar with such conventions. Training, work instruction sheets, and signage are crucial.

Dispensing Systems A storage cabinet for flammables may suffice for the storage of the small transfer containers. Even in this small area, it is important to ensure that it is indoors and protected against airborne contaminants such as dust and moisture. Stock rotation is just as crucial for small container storage as is inventory control. Too little stock on hand means that the machines may operate with too little lubrication. Too much stock means that the lubricant may degrade beyond its useful life before it reaches the machine. Next, some sort of dispensing container is required to get the lubricant into the system as previously shown in Figure 3-7. Proper oilcans are designed to exclude extraneous contaminant. They have spouts that dispense oil inside the machine and not outside. Although the human eye may not see any contaminant and thus assume that new oil is clean oil, particles of silica from the dust in the atmosphere or from production activities can have a serious impact on the wear rates of the equipment. In larger operations, the use of 55-gallon drums is often the norm. Indoor storage is crucial for this arrangement. The shelving should allow the drums to be stored on their sides with the bungs at three and nine o’clock to ensure an airtight seal. Outdoor storage is not recommended because water can accumulate on top of the drum, as shown in Figure 3-1. This can lead to corrosion and water ingression, causing lubricant damage. Carts should be available for moving the drums from the delivery point to the racks.

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When several tiers of shelving are used, appropriate equipment such as a drum stacker should be readily available for lifting to higher levels as shown in Figure 3-8. Some lubrication technicians prefer to dispense manageable amounts from drums into smaller 1/2-gallon containers.

Figure 3-8 Drum Stacker

Although the most common method of dispensing oil from the drum is to use a hand crank pump, this allows contamination in the drum to be dispensed into the system. More proactive organizations now use a filter cart, which may be capable of carrying the drum, drum-pumping, and filtering the oil, as needed. A typical filter cart is included in Figure 3-9.

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Figure 3-9 Filter Cart

These are recommended where it is necessary to dispense from the drum directly into either a smaller container or into the machine. Use caution when standing up a drum at any time because it is possible for a sharp object, such as a nut or stone, to pierce the bottom of the drum, causing spillage. Containers may need quality desiccant breathers to avoid dust and moisture ingression. Sight glasses or level gages will help technicians know when to reorder lubricants. Sampling points on stored containers allow analysis to be performed at regular intervals, thus ensuring the quality of the stored lubricant. Provisions should be made for cleaning the containers at regular intervals. The area will require adequate drainage for catching spillage or leakage, and environmental concerns must be considered. Ideally, the pumping station and dispensing points should include filtration units to ensure clean delivery of the oil to the system. They may include flow meters for the management of lubricant consumption in each area.

Lubrication Technicians and the Digital Age Most organizations now operate CMMS systems to which the oil room should be linked. Whether it is the issuing of daily Work Orders, the logging of top-up volumes for each system, or the stock and inventory control of the lubricants, there is a definite need for the oil room to link to the network. Although the location of a computer may not be essential in the oil room, the use of hand-held Personal Data Assistants (PDAs) would assist the lubrication technician in synchronizing data between the unit and the network.

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Lubricant Storage and Handling Modern best practices involve the use of well-designed lube stations and oil houses for the protection and management of lubricants. These need to be located at strategic points in the plant to minimize unnecessary handling and transport. Below are general guidelines for achieving best practices in lubricant storage and handling: •

There needs to be a documented procedure for receiving and inspecting new lubricant deliveries, including acceptance criteria.

•

Agreement with the local lubricant distributor regarding its role in optimizing lubricant storage and handling practices. This needs to include the occasional reconditioning of containers.

•

For all containers as large as a drum, a means of dispensing including pump/gravity, filter, and breather needs to be readily available.

•

There needs to be a safe and efficient means of transporting lubricant products to storage areas, and from storage areas to the machines. In the case of transporting lubricants to the machine there needs to be a procedure for using top-up containers for make-up oil and totes/drums for oil changes.

•

There needs to be a procedure for rotating stock, inspecting, and condemning stored lubricants.

•

Storage areas need to be bright and well ventilated with proper access to lubricants by forklifts or other transport equipment.

•

Horizontal racking (Figure 3-8) is recommended for storage of drums and small totes.

•

Shelving of top-up oil cans and small lubricant containers should be in explosion-proof cabinets.

•

Storage areas should have protection against leakage including the use of berms for containment. It is generally advised that the storage area be cleaned on a weekly basis. All spills should be cleaned up immediately.

•

All containers should have sealed, tight connections including drum pumps, fill pipes, taps, and vents.

•

All oil dispensed to top-up containers should be pre-filtered whenever possible. These containers should be capped and closed to the atmosphere. They should be cleaned routinely. Open-mouth top-up containers are not acceptable. All top-up containers should be dedicated to particular lubricants and marked accordingly.

Figure 3-10 shows an example of a gravity feed lube station and the proper method of venting the drums (or totes if used) to reduce moisture and particle ingression.

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Figure 3-10 Gravity Feed Lube Station

Depending on fluid viscosity and head, spin-on filters should be mounted on the discharge lines leading to the nozzles, one per tote. Considering that dispensing is accomplished by gravity, it may be necessary to use large-can spin-ons for higher viscosity fluids. The spin-on heads can be mounted directly onto the rack. Figure 3-11 shows another alternative method where space is at a premium. It uses a Seavan container and a vertical drum arrangement. Note that spin-on filters are used in conjunction with the hand-pumps to provide filtration of the dispensed lubricant. The red plastic bags hanging from each drum contain peel-off labels that are used to label the secondary container. Note that the tips of each tube downstream of the hand-pumps are sealed to keep contaminants out. Breather vents are installed in the small bung of each drum to protect the drum from contamination as it breathes.

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Figure 3-11 Seavan Container

The storage and dispensing area is really the bottleneck of the entire lubrication process. Failure to adequately design and maintain the equipment, process, and vicinity can result in the chronic introduction of contamination into the lubricant supply. Every machine in the plant is going to be affected by the lubricants flowing through this area and the care and attention they receive. Focusing resources to ensure quality preservation in the storage and dispensing of lubricants will significantly improve lubricant-driven machinery reliability.

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4

SAMPLING TECHNIQUES

The single most important activity with regard to oil analysis is the practice of obtaining a representative oil sample. An oil sample that is not representative of the condition of the oil in the reservoir, or the quantities of wear particles or contaminants, will give false and misleading information to oil analysts and those charged with implementing recommendations from the oil analysis results. The total equipment needed for good sampling varies according to the type of sampling required, the machinery and the lubrication systems, designs of the oil sumps, reservoirs, housing, line arrangements, and so on. Because there are many different sampling procedures, they are not addressed in detail in this section; however, detailed sampling procedures can be obtained from various suppliers. Included in this section are detailed presentations of the various types of sample points.

Sample Points The key to obtaining adequate and representative oil samples is the requirement that the machines are in service, in operation, and at or near typical loading conditions. The selection of the oil sampling points should not be driven by ease of sample procurement, but rather should be optimized to that location in the system that is most representative of the data desired. Typically, a single primary sample point that ensures maximum data density for analysis will be designated. This means that the critical monitored parameters for a system should be at their peak within the confines of the normal lubricant cycle so that the analysis trends can be significant. As an example, systems for which wear particle concentration is an important monitored parameter will have a specific sample point selection strategy. The primary sample point will be located at a point in the oil flow where the oil has passed through the lubricated contacts, but before any point at which the concentration of wear will be diluted or diminished through filtration, mixing, or settling in the reservoir. Often, machines, as supplied by the manufacturer, do not have easily accessible sampling points for obtaining this required information. Therefore, it could be necessary to retrofit this equipment with sampling valves or fittings that enable personnel to obtain the needed representative sample. In other instances, operating conditions may prevent obtaining an optimal sample. For instance, in a splash bath arrangement where there is no defined oil return, it might be necessary to take the oil sample from the reservoir itself, to establish the first accessible point in the lifecycle of oil circulation that includes the information desired. In this case, the area within the reservoir should be carefully selected to maximize the concentration (data density) as much as possible within the machinery limitations. In other instances, more than one oil sample may need to be defined for a 4-1

EPRI Licensed Material Sampling Techniques

given piece of equipment. As mentioned previously, a primary sampling point might be defined by the need to obtain information about wear particle concentration. Secondary sample points may be defined to provide other information, such as post-filter condition, condition after an oil supply pump, condition of the tank bottom, and so on. These secondary oil-sampling points are typically defined for the purpose of follow-up samples. They are performed on an infrequent basis or to better define the condition of a system’s lubricant after initial indications are provided by the primary sample point analysis. In a complex circulating oil system, it is not uncommon to have a single primary sample point, and as many as a dozen secondary sample points. In main turbines, for example, the primary sample point may be defined as the sample taken from the common bearing return header prior to its mixing with the reservoir contents. The secondary points may be defined as the drain valve at each of the bearings, the tank bottom condition, the condition on the discharge of the oil supply pump, and a sample taken from the discharge of the on-line lube oil conditioner. There are a number of commercially available oil sampling valves or fittings that can be used to retrofit equipment with inadequate sampling options. The cost associated with such retrofit projects can be minimized through a carefully orchestrated engineering plan that seeks to define a limited number of installation options (which are generically evaluated for impact on equipment and systems). Once approved for installation, the individual equipment can then be modified through the use of approved installation scenarios by using defined plant procedures to ensure proper installation and consideration of all engineering criteria.

Sampling Port Location—General Discussion In general, the best sampling methods involve some sort of sampling hardware retrofit. This can be both time consuming and costly depending on the exact hardware chosen and the number of machines involved. However, this investment is a wise choice if a serious oil analysis program is envisioned. For many utilities, the traditional methods of sampling large lubrication and hydraulic systems consist mostly of reservoir sampling. In the case of reservoir sampling, samples are drawn either by drop-tube vacuum sampling from a fill port, or off the bottom of the reservoir from the drain port. However, advanced oil analysis programs locate all sampling taps, where possible, on the drain line of circulating lubrication systems and on the return line of hydraulic systems. This permits access to wear debris and ingested contaminants before these materials are removed by filters, separators, or by settling action. Likewise, moisture levels are precisely represented from entry points such as steam impingement, process fluids, and coolant leaks. Many of the recommended sampling points follow a consistent pattern. Presented here are six general cases for installing sampling fittings. These different cases describe the general procedure for installing the sampling hardware. Refer to this information when instructing maintenance technicians on how to install sampling valves and fittings. An example of sampling port installation is found in Appendix A.

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Case A—Dry Sump, Horizontal Drain Line Figure 4-1 illustrates how a single sample is to be taken to assess wear metals and fluid condition coming down a large return header to a fluid reservoir. Sampling ports on this vented drain line should be on the underside of horizontal tubing where there is reasonable certainty that there will be a uniform body of fluid. To ensure turbulence and good mixing of the fluid prior to sampling, it is recommended that the sample location be near or just after an elbow. The use of a mini-mess type sampling installed at this point can be interfaced with a vacuum pump sampler in order to draw fluid from the unpressurized zone (drain line). Alternately, a ball valve can be attached to the underside of a horizontal drain line allowing fluid to flow by gravity into a sample bottle. A male quick-connect valve is yet another option, allowing the mini-mess valve or ball valve to be carried from point to point. The connection, regardless of the port hardware, can be drilled and tapped or hot-tapped, depending on various factors. Figure 4-1 shows examples of various options for drain-line sampling taps.

Figure 4-1 Drain Line Sample Points

Case B—Dry Sump, Vertical Drain-Line Figure 4-2 shows how diagnostic sampling ports can be installed on each of the drain lines coming from the individual bearings toward the header. This will enable troubleshooting of problem bearings in the event of non-conforming readings of wear metals from the main header sample. There is considerable added expense and effort to add these additional bearing drain-line ports and, in some cases, it may be best to delay this until a convenient time in the future.

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If horizontal sections of these dry sump-bearing drains are available, then the ports can be installed in any of the ways briefly described in Case A. However, in the event of the typical case that these lines are vertical down-comers, a trap will need to be installed to collect the oil in front of the sample valve.

Figure 4-2 Vertical Drain Line with Sample Trap

The most convenient way to access the fluid adjacent to the trap is to use a mini-mess valve as shown in Figure 4-2. Because the fluid will not be under pressure, the use of a common vacuum pump will be required to pull the oil into the sample bottle. Another alternative is to use a ball valve or a quick-connect coupling as mentioned in Case A. Naturally, the mini-mess with the vacuum pump has its advantages because the pump facilitates the flow of oil into the bottle and the bottle can be protected from atmospheric contamination using a simple zip-lock type of sandwich bag. Case C—Pressurized Feed Line It is often desirable to sample the oil as it is being supplied to the bearings and other lubricated components. This should always be done after filters or other contaminant removal 4-4


devices/separators. It should also be done after heat exchangers, if used. The use of this sampling location is best combined with a drain or return line sample. The drain/return line sample is used for predictive purposes for the detection of abnormal wear conditions. However, the pressure line sample serves to ensure that oil being delivered to bearings and lubricated components meets important criteria of cleanliness, dryness, and a host of other important physical properties. Because the fluid is under pressure at this location, sampling can be more easily accomplished. The use of a mini-mess type valve enables simple probe-on sampling to be accomplished. Alternatively, ball valves and quick-connect couplings can be employed as well. Figure 4-3 shows the common options for installing a sample valve on a pressurized line. Figure 4-4 shows the use of a mini-mess on a high-pressure line.

Figure 4-3 Pressurized Feed Line Options

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Figure 4-4 High-Pressure Line with Mini-Mess Valve

Case D—Pressurized Return Line Most hydraulic systems, as shown in Figure 4-5, return fluid to the tank under pressure, as opposed to gravity drain flow. These pressurized return flows are a continuous body of fluid without air zones occupying the lines (as in the case of vented bearing drains). It is also common for the fluid to pass through a filter on its way back to the tank). Here, a pressurized return line exists; therefore, the oil should be sampled just prior to the filter. If an upstream filter pressuregage port is available, then this is an ideal location for installing the sample valve; simply remove the port plug and install the valve at that point (point P in Figure in 4-5). If a pressure gage is already occupying the gage port, then a T-fitting can be installed to enable the port to be shared. Because this is a low-pressure zone, the ideal sample valve is a standard mini-mess.

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Figure 4-5 Pressurized Hydraulic System

Fluid flowing straight back to the tank (no filter) should be sampled on elbows, if possible. They can often by drilled and tapped or hot-tapped. If a pipe or header leads straight back to the tank vertically, sufficient turbulence for a uniform (well-blended) sample may not exist. In this case, it is recommended that the line be followed back to the machine to see if an elbow can be found, or an otherwise more turbulent location (such as where fluid is just exiting the machine). If process debris on the return line is found to be excessively high and interferes with the monitoring and management of oil cleanliness (cleanliness targets are routinely not achieved), then another sampling port needs to be installed on the pressure line downstream of the pressureline filter, leading to bearings or actuators (refer to Case C for sample ports on pressure lines). Here, the cleanliness, dryness, and other physical properties of the oil can be monitored, leaving the return line sample for wear debris analysis only. Case E—Wet Sump, Splash, or Bath Lubrication There are numerous instances where bearings or gear units are lubricated without the benefit of oil circulation. Too often these systems are either not sampled or they are sampled improperly, for example, using the drop-tube vacuum pump method or directly from a drain port. With the proper hardware, these deficiencies can easily be rectified. The objective is to obtain a sample “on-the-run” from a consistent location at a hot, active fluid zone. The best way to do this is to use a pre-existing drain port. Often, it is easiest to weld a short tube onto a bushing. The bushing 4-7


is threaded into the port. A mini-mess valve would be installed into the bushing, on the outside of the casing, to access the fluid for sampling. In many systems, two drain ports exist. If an available drain port exists that is not otherwise needed for purging oil from the bearing or gear compartment, it can be fitted with oil sampling hardware similar to that shown in Figure 4-6.

Figure 4-6 Wet Sump Sampling Options

If there is not an available port for sampling because a level gage is occupying one of the ports, this port can also serve as a sample port. There are various possible configurations, one such configuration is a common two-way ball valve (preferably with a Teflon seat), as shown in Figure 4-7. The valve connects the fluid to the gage during normal operation. When a sample is to be taken, the valve is rotated, thus restricting access to the level gage (which is a dead zone) and allowing fluid to flow freely into the sample bottle after an adequate flush. It is highly desirable to weld an inward static sampling (SS) tube, as shown, allowing the fluid to not be pulled off the bottom of the casing but instead from an active (moving) zone of the system away from the wall or floor of the casing.

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Figure 4-7 Two-Way Valve for Sight-Glass Sampling

In situations where there is only one drain port, an SS tube should be welded to the end of a bushing, which threads into the port cavity. A ball valve or mini-mess valve can then be threaded into the bushing for sampling. If a mini-mess valve is to be used, a vacuum pump will be needed during the sampling process. To use the port for the purpose of draining the gear case or bearing housing, the bushing is completely threaded out. If desired, these systems can be fitted with male quick-connects on the drain and fill ports to facilitate attachment of an off-line circulating filtration cart (Figure 4-8). The circulating flow enables sampling from the filter cart, from the pressurized flow line, as shown in Figure 4-8. Upon completion of sampling, the filters can be valved-in to clean the oil. This method achieves sampling objectives, improves contamination control, and eliminates the need for scheduled oil changes designed to remove contaminants. Likewise, all of this can be accomplished while the machine is running, avoiding the need to schedule machine downtime for this PM service.

Figure 4-8 Sampling with Portable Off-Line Cart

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Here are some general guidelines for applying this procedure: •

Select a flow rate that is appropriate for the fluid’s viscosity, considering the temperature at which the oil will be sampled.

•

Outfit the filtration cart with dirt and water removal capabilities.

•

Outfit the cart with a bypass around the filters so that oil can be sampled before engaging the filters.

•

Run the cart in the bypass mode for several minutes to homogenize the fluid.

•

It is sensible to dedicate a cart to a particular fluid type to avoid the burden of constant flushing.

•

Avoid changing sump volume upon engagement of flow by leaving the plumbing of the cart and filters full of oil of the type used in the system.

Once a sample is drawn, engage the filters for a period of time sufficient to turn the sump volume over seven times for single-pass filtration. Turning the volume over seven times equals the equivalent of a single pass from one container to another. If two-pass filtration is desired, turn the volume over 14 times. If desired, a second sample can be taken to ensure that target cleanliness objectives are met, and to provide a reference of comparison for the next sampling and filtering process. Case F—Wet Sump, Circulating Lubrication In those instances where the wet sump has on-board circulation to feed components, and the lubricant drains back to the sump, it is preferred to sample from the circulating system after the pump and before the filter (if applicable). During operation, the oil in the sump and the circulating oil are homogenous before the filter. The pressure provided by the pump improves the convenience of sampling. Install the sampling valve or mini-mess on an elbow opposite the direction of the flow to avoid particle flyby and so that the particles don’t need to change direction to exit the valve. If this sampling location serves as the primary sampling location for assessing the lubricant’s condition and contamination level and the machine’s condition, then install the sampling valve or mini-mess before the filter, if one exists (Figure 4-9 at arrow). When a filter is present, sample after the filter to assess its performance or to ensure that the components receive clean, dry oil. The after-the-filter location is typically reserved for troubleshooting when an over-limit particle count is observed at the primary location.

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Figure 4-9 Circulating System – Wet Sump

Power Generation Specific Sampling Locations After having given a number of general sampling scenarios, Table 4-1 illustrates the proper approach for a number of common types of power generation facility equipment. These examples can serve to illustrate the appropriate installation method through the use of drawings and by noting the specific locations on actual machinery pictures. In every case, purge volumes must be calculated or measured and the needed purge amount included in the sampling procedures. In some cases, the needed purge volume can be determined by monitoring the temperature of the oil as it exits the sampling fitting or valve. As the oil is first drained, deadleg oil will be at or near room temperature. As the deadleg volume is eliminated, the temperature will gradually rise until it reaches the reservoir internal bulk oil temperature. Internal reservoir temperatures can be high, so be sure to take precautions to prevent injury while sampling. In some cases, the required hardware installation can be a significant cost or work scheduling issue. Where the installation of sampling fittings is so sufficiently slow as to hamper the progress of the program, temporary measures should be taken to obtain the best possible sample in the given configuration. Oftentimes, this involves using a standoff rod and inserting it through the fill cap. A metal rod with 1/4-20 washers tack-welded to it and cut on an angle can make an adequate standoff rod. Whenever placing anything inside the reservoir, be sure that there is no risk of leaving any foreign materials behind.

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EPRI Licensed Material Sampling Techniques Table 4-1 Power Plant Equipment/Lubrication Systems Equipment

4-12

Procedure/Notes

Main Turbine Reservoir Oil Return Line

Indicated by the letter “E” in the drawing, the return line to the main turbine is the primary sample point for obtaining a composite of the turbine bearing drains. By using a long-handled scoop with a restraining lanyard, oil can be scooped from the area below the pipe where it is free-falling back to the reservoir. Getting the oil at this point maximizes the data density.

Diesel-Driven Generator Without a Return Line

There is no direct way to sample the oil to maximize particulate concentration; therefore, take a sample from the dipstick to ensure repeatability.

Cooling Water Pump

Installing a sampling minimess on the bottom drain with a pitot tube standpipe is the best sampling option.

Large Falk Gear Box (numerous applications)

Removing the drain line and installing a reducing bushing and sampling fitting ensures consistent samples.

Picture

Drawing

Optimal installation for mounting a mini-mess

EPRI Licensed Material Sampling Techniques Table 4-1 (cont.) Power Plant Equipment/Lubrication Systems Equipment

Procedure/Notes

Medium Vertical Motor

These motors can be sampled through the fill cap with a standoff rod, or preferably from a reducing bushing and sampling fitting installed at the drain plug.

Electro-Hydraulic Control (EHC) System

Power plant EHC systems are best sampled on the return line before the return line filters.

Mechanical Draft Cooling Tower Fan Gearbox

With the filter on the re-circulation rig in bypass, the oil in the gearbox is circulated and sampled from a valve on the rig.

Picture

Drawing

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EPRI Licensed Material Sampling Techniques Table 4-1 (cont.) Power Plant Equipment/Lubrication Systems Equipment

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Procedure/Notes

Large Vertical Motors

Many large vertical motors in power plants only provide access to an inner bearing reservoir through long pipes that penetrate the motor casing. Use of a mini-mess sampling fitting with a long, small-diameter pilot extension allows live zone samples to be obtained.

Large Horizontal Motors

By simply replacing the side drain plug with a small reducing fitting and minimess, a reliable, repeatable sample can be easily obtained.

Pulverizer Gear Boxes

Pulverizer gearboxes should be installed with a recirculatory filtration system because of the significant damage posed by the abrasive particles. This loop can then be used to obtain a reliable sample.

Feedpump and Turbine Bearings

By placing a vertical trap and mini-mess, primary samples can be established at the individual bearings. Cost and scheduling may dictate that the sample come from the drain of the dry-tank reservoir.

Picture

Drawing

EPRI Licensed Material Sampling Techniques Table 4-1 (cont.) Power Plant Equipment/Lubrication Systems Equipment Induced Draft (ID) and Forced Draft (FD) Fans

Procedure/Notes

Picture

Drawing

Fan bearings with an oil inlet and outlet line in a recirculation configuration should be sampled on the return line, as shown in the drawing.

Non re-circulating fan bearings should be sampled by installing a mini-mess fitting at the bearing housing.

Boiler Circulating Pumps

The top picture shows the bottom of the boiler circulating pump reservoir, and a possible sampling location at the “T”. However, a safer and probably more consistent sample can be taken by installing a sampling fitting at the location shown by the red arrow in the lower picture. By sampling after the pump and before the filter, an optimal sample can be obtained.

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5

CONTAMINATION CONTROL

Contamination control falls under the category of proactive maintenance, whereby the strategy is to minimize the ingression of particulate liquid and other undesirable contaminants from the lubricants, thus maximizing both lubricant and machinery life. The most commonly addressed contaminants in power plant lubricants are particulate contamination from dust, dirt, wear, etc., and moisture. It is important for the plant to recognize the impact that contaminants can have on machinery life, and some level-of-awareness training is typically required to communicate this knowledge throughout the plant. The control and prevention of lubricant contamination is a process that touches nearly every workgroup in the plant. From the handling of new lubricants by storeroom personnel to the maintenance practices during overhauls, the opportunities to introduce contaminants are numerous. Figure 5-1 shows a typical machine and the various checkpoints that are evaluated for potential contaminant ingression. Contamination control is a three-step process of identification, elimination, and exclusion. By adopting a program that addresses the most important contamination scenarios threatening a plant, effective protection from contaminants can become a basic part of the work practices of the utility.

Figure 5-1 Machine with Checkpoints

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EPRI Licensed Material Contamination Control

Contaminant Identification The identification process involves establishing the proper sampling and analysis practices that ensure routine evaluation of lubricants for the presence and quantity of important contaminants. The tests that are chosen and their frequency of performance are functions of the types of predominant contaminants and the degree of opportunity for their insertion into the lubrication process. Typical and opportune contaminants for each system must be defined in order to establish the required testing that would be needed to detect their presence. For example, in the coal handling sections of a coal-fired plant, the presence of abrasive coal particles is dominant and universal. The reliable operation of machinery in these areas is almost a direct correlation to the ability to provide adequate protection from coal dust ingression. In these areas, it would be desired to establish oil analysis test slates and sampling frequencies that provide maximum sensitivity to the presence of these particles. In pulverizer ball mills, some plants do not perform particulate count, because of the typically high levels of coal dust present. In fact, this is just a case of hiding from the problem. Just because testing is not done for something does not mean that it is going to go away. Instead, focus is needed on the analysis to highlight the presence and trends in the quantity of destructive contaminants present. Only by doing so can corrective and protective strategies to minimize the negative effects of contaminants be adopted. Table 5-1 shows typical lubricant tests and their applicability in detecting lubricant contamination. Table 5-1 Lubricant Test/Contaminations

Once the appropriate testing regimen has been established, acceptance criteria must then be set (both alarm and alert levels), which will indicate when action must be taken to prevent damage, either to the lubricant itself or to the machine that it lubricates. These limits should have a clearly prescribed course of action that seeks to either minimize the ingression of the contaminant or 5-2


actively works to remove its presence in the reservoir. In addition to condemning limits and warning levels, targets can also be set to try to achieve, proactively, an even lower level of contamination, which would further result in the extended life of the lubricant and the machine. Ultimately, when the source is discovered it must be possible to evaluate the opportunity to correct it, or to possibly recommend or employ counter measures in the short term that will allow the machinery to achieve its needed function until the work evolution required to correct the problem can be scheduled. If it is found that the designed defensive measures against contamination are functioning as they should, and yet are inadequate in reducing the sources of contamination to acceptable levels, it may require investigating design changes to improve the ability of the machine to keep out these contaminants. Examples of this include the use of desiccated and high-efficiency filter breathers on many types of older oil reservoirs as shown in Figure 5-2. These help to minimize ingression through natural breathing of the reservoir through an open or coarse-meshed screen. The high efficiency filtration of the breather minimizes the ability of particulates to enter the reservoir through the headspace. The use of desiccants in areas prone to moisture allows the breathing process to continue without the ingression and condensation of an unacceptable level of moisture.

Figure 5-2 High-Efficiency Filter Breather

When there are indications of the excessive presence of contaminants, a first look should be directed to the machine itself and any design features that are typically employed to exclude these contaminants. Their operation should be checked to determine if the increased presence in contaminants is an indication of the failure of these preventive measures. For example, when it is noted that there is an increase in the level of particulates in an oil reservoir, any installed on-line 5-3


filtration systems should be checked to see if they are operating properly, or if hatch or penetration seals have failed. These conditions can be indicated through monitoring analyzed particulate concentrations in the oil, visual inspections of hatches and openings, and the use of pressure differential gages on filters. Following are some of the key areas of contamination concern in a power plant, and a discussion of appropriate monitoring strategies. Particulate Contamination Particulate is the enemy of bearings. SKF, a manufacturer of rolling element bearings, states that, “bearings can have an infinite life when particles larger than the lubricant film are removed.” Of course, there are many factors that bring bearings to premature demise, but contamination of the lubricant can account for as much as 70% of all bearing failures. Once the impact that these unwanted particles can have on the reliability of the machinery is recognized, every effort must be made to minimize their presence in the lubrication oil. Some of these strategies have been discussed in the specific sections of this document where they apply, such as Section 3, “Storage and Handling,” and Section 8, “Lubrication/Relubrication Practices.” The most common unit of reporting fluid cleanliness is the International Organization for Standardization (ISO) Code System. This convention is covered under ISO Standard 4406:99 (Figure 5-3). In this standard, the number of particles in three different size categories, >4 µm, >6 µm and >14 µm, are determined in a one-milliliter sample. However, the ISO standard is not the only method by which the cleanliness of an oil sample can be reported. Other standards include NAS 1638 and MIL-STD 1246C, as well as outdated standards such as the Society of Automotive Engineers (SAE) fluid cleanliness rating system. Whichever method of reporting is selected, the first step is to count the number of particles in a volume of fluid.

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Figure 5-3 ISO Standard

As outlined below, there are three basic methods that can be used to determine the absolute number of particles in any given sample: Optical Microscopy (ISO 4407) The original method for determining fluid cleanliness levels was to take a representative portion of the sample and examine it under an optical microscope. In this procedure, the particles are manually counted, which can then be used to determine the fluid cleanliness of the bulk sample. Although this method may seem outdated, slow, and cumbersome, it is still in use today and considered by many to be the most reliable and accurate method of particle counting, because it is unaffected by some of the limitations of the more modern, automated methods. Automatic Optical Particle Counting (ISO 11500) Perhaps the most widely employed method today for determining fluid cleanliness is to use an automatic optical particle counter. There are a variety of instruments commercially available to optically count particles, from portable units for on-site use that cost as little as $15,000, to large, sophisticated lab-based instruments that may cost in excess of $40,000. There is even a low-cost, on-line optical particle counter available for under $1,000. However, all instruments, whether they are a hand-held unit or a full lab instrument, use one of two methods, either a white light source or, more commonly today, a laser. In a white light instrument, particles pass through the capillary detection zone and create a shadow on a photocell detector. The drop in voltage produced by the photocell is directly proportional to the size of the shadow and, hence, the size of the particle passing through. 5-5


In a laser-based instrument, due to the near-parallel nature of the laser beam, light scattering from the unimpeded laser beam is minimal because it is focused into a beam stop until a particle passes through the instrument. As the laser strikes the particle, light scatters and hits the photocell. Just like a white light instrument, the change in voltage across the photocell is directly related to the size of the particle. In the laser-based instrument, one looks at an increased signal against what should be a zero background (in theory). Laser optical particle counters are generally considered to be slightly more accurate and sensitive than white light instruments. There are several subtleties that must be considered with the automatic optical particle counters. First, for the most part, particles from used oil samples are not perfectly spherical. This can create problems for optical counters because of the one-dimensional ISO 4406:99 coding scheme, which classifies particles that are 5 microns across the minor axis, but 40 microns across the major axis. To resolve this issue, developers of automatic optical particle counters have devised a compromise known as the equivalent spherical diameter. With the equivalent spherical diameter method, a particle is counted in the size-range under which the shadow, or scattering effect observed, would have appeared if the particle had been a perfect sphere. This allows the average fluid cleanliness to be estimated, permitting the ISO code to be trended over subsequent samples. Another concern is the effect of false positives. For example, both air bubbles and free and emulsified water appear as if they are a particle using the optical particle counting method. Although the effect of air and water can be negated by using an ultrasonic bath and vacuum degassing to remove air, and solvent extraction to dissolve free and emulsified water, other false positives are possible with multiple particle coincidences and additive floc. For this reason, care and attention to procedural details must be exercised when performing optical particle counts. Pore Blockage Particle Counting (BS3406) The pore blockage method is a widely used method of obtaining an automatic particle count. In this method, a volume of fluid is passed through a mesh screen with a clearly defined pore size, commonly 10 microns. There are two instrument types that use this method. One instrument measures the flow decay across the membrane as it becomes plugged while pressure is held constant, first with particles greater than 10 microns and, later, by smaller particles as the larger particles plug the screen. The second measures the rise in differential pressure across the screen while the flow rate is held constant. Both instruments are tied to a software algorithm, which turns the time-dependent flow decay or pressure rise into an ISO cleanliness rating according to ISO 4406:99. Although pore block particle counters do not suffer the same problems as optical particle counters with respect to false positives caused by air, water, dark fluid, etc., they do not have the same dynamic range as an optical particle counter. Because the particle size distribution is roughly estimated, they are dependent on the accuracy of the algorithm to accurately report ISO fluid cleanliness codes according to ISO 4406:99. Nevertheless, they accurately report the aggregate concentration of particulates in the oil and, in certain situations (particularly for dark fluids such as diesel engine oils and other heavily contaminated oils), pore block particle counting does offer advantages.

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There can be little doubt that the ability to quantify an oil’s fluid cleanliness using particle counting is the most valuable tool in any proactive maintenance program. Therefore, this makes consistent and accurate particle counting one of the most important tasks in oil analysis. By adopting a valid particle counting method, and obtaining representative samples, the proper actions for addressing oil cleanliness issues can be directed by the oil analysis results. Moisture Water is perhaps the most harmful of all contaminants, with the exception of solid particles. Although the presence of water is often overlooked as the primary root cause of machine problems, excess moisture contamination can lead to premature oil degradation, increased corrosion, and increased wear. Proper sampling to determine the quantities of water present requires evaluation of the lubrication system for each machine. To determine the moisture levels that can potentially affect the formation of the lubricating film and the corrosion of bearing surfaces, the oil in the live-zone should be observed. In circulating systems, samples taken from the supply lines indicate the quality of the oil supplied for the lubricated components. Samples taken on the return lines include the same information, plus any additional water being introduced to the system at the lubricated components. The primary sampling location for a return line sample, taken to show the maximum amount of moisture present in the live-zone path, would typically be a position after any in-line cooler. This is different, however, than for the maximum concentration of moisture in the system. This would typically be found in the bottom drain of the reservoir, where moisture can accumulate by design. That sample is also important, however, to indicate excessive accumulation of moisture in the sump, the need to investigate sources, and possibly to clean the tank. When unacceptable levels of moisture are indicated from the primary sampling point, additional follow-up samples are typically taken to help pinpoint the source. All too often, plant staff will dismiss a low, but higher than normal, moisture level in a sample as condensation. Although condensation of ambient moisture is a feasible route of ingression, normal system design should prevent it from adding significantly to the moisture levels in the oil. Even low levels of moisture in a large reservoir, when showing a clear increasing trend, can be valuable indicators of emerging moisture problems such as leaky coolers, leaky pump seals, or other continuous ingression. When discovered and rectified in the early stages, such problems can be headed off before leading to reliability threatening conditions. The following tests can be used to determine the presence of water. Visual Crackle Test The simplest way to determine the presence of water in oil is to use the Visual Crackle test. Although this is an effective test for identifying free and emulsified water, down to approximately 500 ppm, its biggest limitation is that the test is non-quantitative and fairly subjective. False positives are possible with entrained volatile solvents and gases. Nevertheless, as a screening tool in the lab and the field, the Crackle test will always have a role to play where a quick yes or no answer is required for free and emulsified water.

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Fourier Transform Infrared Spectroscopy (FTIR) Analysis FTIR can be an effective method for screening samples containing in excess of 1,000 ppm of water, provided a correct new oil baseline is available for spectral subtraction. However, due to its limited precision and comparatively high detection limits, FTIR is not adequate in many situations where precise water concentrations below 1,000 ppm, or 0.1%, are required. Dean and Stark Method The classic method for determining the presence of water in oil is the Dean and Stark distillation method (ASTM D95). This test method is fairly cumbersome and requires a comparatively large sample to ensure accuracy, which is why it is rarely used in production-style oil analysis labs today. The method involves the direct co-distillation of the oil sample. As the oil is heated, any water present vaporizes. The water vapors are then condensed and collected in a graduated collection tube, such that the volume of water produced by distillation can be measured as a function of the total volume of oil used. Karl Fischer Moisture Test The Karl Fischer Moisture test is the method of choice when accuracy and precision are required in determining the amount of free, dissolved, and emulsified water in an oil sample. All Karl Fischer procedures work in essentially the same way. The oil sample is titrated with a standard Karl Fischer reagent until an end-point is reached. The difference in test methods is based on the amount of sample used for the test and the method used to determine the titration end-point. The results can be reported as parts per million, or as a percent of water in the sample. Calcium Hydride Test Kits One of the simplest and most convenient ways to determine water concentrations in the field is by using a Calcium Hydride test kit. This method employs the known reaction of water with solid calcium hydride to produce hydrogen gas. The amount of hydrogen gas liberated is directly proportional to the amount of water present in the sample. Therefore, the water content of the sample can be determined by measuring the rise in pressure in a sealed container due to the liberation of hydrogen gas as any water in the sample reacts with the calcium hydride. Used correctly, these test kits are reported to be accurate down to 50 ppm free or emulsified water. Saturation Meters When the amount of water present in an oil sample is below the saturation point, saturation (dew-point) meters can be used to indirectly quantify water content. The saturation point of an oil is simply the point at which the oil contains as much water in the dissolved state as possible, at a given temperature. At this point, the oil is saturated or has a relative humidity of 100%. Most saturation meters use a thin film capacitive device, whose capacitance changes depending on the relative humidity of the fluid in which it is submerged. Saturation meters have proven to be accurate and reliable at determining the percent saturation of used oils. The biggest drawback with saturation meters is the fact that the saturation point is strongly dependent on temperature, 5-8


as well as on the presence (or absence) of polar species (including additives, contaminants, and wear particles). In addition, with water levels in excess of the saturation point, typically 200 to 600 ppm for most industrial oils, saturation meters are unable to quantify water content accurately. Despite these limitations, saturation meters can be useful trending tools to determine moisture on-site, provided that they are used frequently and routinely. Monitoring and controlling water levels in any lubricating system is important. Whether it is a large diesel engine, a steam turbine, a hydraulic system, or an electrical transformer, water can have a significant impact on equipment reliability and longevity. Regular water monitoring, whether it be a simple on-site Crackle test or a lab-based Karl Fischer moisture test, should become a standard condition-monitoring tool. When moisture is the culprit contaminant, look for indications of a possible ingression source, including pump seals, coolers, steam or water leaks, condensation, and other sources. Any of the features of the machine that are designed to prevent these sources should be checked to determine the reason for the increasing values of the water contaminant. Shaft seal checks, cooler pressure tests, sealing surfaces on reservoirs where water or steam may be getting in are examples of a functional review in establishing the ingression path for water contamination. Coolant The most common example of non-water coolant used in power plants is ethylene glycol, also known as automotive anti-freeze. Glycol can have a destructive effect on the oil itself and will diminish its ability to maintain the lubricating film. Glycol is sufficiently different chemically from oil to make its detection rather simple. One of the existing analysis methods to look for the markers for increasing glycol levels in the oil sample is typically used. The two most commonly used methods are FTIR and elemental spectroscopy. FTIR Spectroscopy FTIR spectroscopy is effective for indicating the presence of the hydroxyl group in a sample. Typical lubricating oils do not have any hydroxyl present, so the appearance of a peak in this area is notable. Both water and glycol are significant contributors to hydroxyl concentration in an oil sample. If a sample does not indicate the presence of water by other tests, but the hydroxyl is confirmed, it is a good indicator of the presence of glycol. There are other peaks in the FTIR spectrum that point to glycol as well, but the accuracy of the FTIR method is quite limited. It should only be used as a screening tool to detect glycol presence. Elemental Spectroscopy Atomic emission and inductively coupled plasma (ICP) spectroscopy are commonly used tests for the analysis of used oil. In systems where the potential exists for glycol to contaminate the oil, the chemical make-up of the glycol should be baselined to determine elemental ratios. The key elements of Boron, Sodium, and Potassium should be measured as a way to confirm the presence of glycol in the oil. Elemental spectroscopy is preferred to FTIR and other available methods because it can detect the reaction byproducts of glycol contamination where the other methods cannot. 5-9


Diesel engines are a common location for glycol to show up in oil samples, and there are other uses of glycol in power plant cooling applications as well. In the case of glycol in engine oil, the interfaces between these two products should be observed to establish possible ingression routes. Gasketed or cooler interface locations that have been compromised and have led to increased levels of these contaminants should also be checked. Fuel and Soot In internal combustion engines, the presence of soot and fuel are contaminants to consider. Soot is a solid byproduct of combustion and is normally present in diesel engines in some quantity. As the level of soot increases, it can lead to clogging of filters and passages. Soot is typically monitored quite effectively by infrared (IR) methods, including both FTIR baseline increases, and specially designed IR soot meters. Excessive levels of soot require an oil change. Fuel leakage into the crankcase oil can be an indication of significant mechanical problems. Fuel can be detected by a number of methods, including viscosity and FTIR. However, these tests are not considered reliable ways to track fuel concentration. Viscosity reductions by fuel dilution can be offset by soot accumulation, and FTIR can be less than effective and can certainly be a poor quantitative indicator. The preferred method is trending of the flash point of the oil, as shown in Figure 5-4. As the fuel concentration in the sample increases, the flash point value will trend downward from the new oil value.

Figure 5-4 Flash Point Indicator

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Air Air may not immediately be thought of as a contaminant, but the presence of air in its various forms may have an impact on the ability of the lubricant to perform its design function. Almost all lubricating oil systems contain some air. Air is found in four phases: free air, dissolved air, entrained air, and foam. Free air is trapped in a system, such as an air pocket in a hydraulic line, and may have minimal contact with the fluid. It can be a contributing factor to other air problems when lines are not bled properly during equipment startup and free air is drawn into circulating oils. Dissolved air is not readily drawn out of solution. It becomes a problem when temperatures rise rapidly or pressures drop. Petroleum oils contain as much as 12% dissolved air. When a system starts up or when it overheats, this air changes from a dissolved phase into small bubbles. If the bubbles are less than 1 mm in diameter, they remain suspended in the liquid phase of the oil, particularly in high viscosity oils. This can cause air entrainment, which is characterized as a small amount of air in the form of extremely small bubbles dispersed throughout the bulk of the oil. Air entrainment is treated differently than foam and is most often a completely separate problem. Some of the potential effects of air entrainment include: pump cavitation, spongy and erratic operation of hydraulics, loss of precision control, vibrations, oil oxidation, component wear due to reduced lubricant viscosity, equipment shutdown when low oil pressure switches trip, micro-dieseling due to the ignition of the bubble sheath at the high temperatures generated by compressed air bubbles, safety problems in turbines (if over-speed devices do not react quickly enough), and loss of head in centrifugal pumps. Foam, on the other hand, is a collection of closely packed bubbles surrounded by thin films of oil that float on the surface of the oil. Figure 5-5 illustrates foaming in a turbine reservoir. It is generally cosmetic, but it must be treated if it makes oil level control impossible, if it spills onto the floor to create a safety or housekeeping hazard, causes air locks at high points, or is so extreme that equipment is lubricated with foam. Small amounts of foam do not necessarily need to be treated unless the system suffers from the air entrainment conditions listed above, although the presence of the foam may be symptomatic of a more serious problem.

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Figure 5-5 Foaming in Turbine Reservoir

Depending on the application, lubricating oils are susceptible to contamination from grease, particulates, sealing materials, other lubricants, process fluids, rust preventives, cleaning compounds, and airborne contaminants. Lithium and calcium grease have a significant effect on foam stability. Particulates act as seeds or nucleation points on which bubbles grow. Anti-foam additives may also be attracted to their surface, reducing their effectiveness in the bulk oil. In practice, dirty oil can foam more than clean oil, although a review of more than 100 used turbine oil samples showed no correlation between ISO cleanliness and foam tendency, indicating that the affects of particulate contamination are much less pronounced in these systems. Water has a destabilizing effect on foam. In practical applications, this means that more foam may be generated by the presence of water, but it will dissipate faster. The net effect may be a slight increase in unstable foam. Oxidation byproducts have been shown in the laboratory to produce very stable foam. It is common practice to coat turbine components with a viscous prelube to provide initial lubrication during startup. Pre-lubes, particularly ones that contain polybutenes, can react with acrylate anti-foam additives. To prevent this, petrolatum (petroleum jelly) or ISO 460 turbine lubricant should be used as a pre-lube to avoid contamination of the working fluid. To evaluate the fluid as the root cause, take a sample and shake it well or observe the condition of the lubricant when the machinery shuts down. Does the foam dissipate rapidly? Are relatively large bubbles floating on top of the fluid or is air dispersed throughout the fluid? A visual examination of this kind is usually sufficient to tell the condition of the oil and, oftentimes, it is not necessary to perform the ASTM D892 foam test. If the foam dissipates rapidly, the oil is doing its job and it is likely a mechanical problem that is the cause. If the foam does not dissipate, the oil is probably contaminated.

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Oxidation Products The products formed from the oxidation of oil include weak carboxylic acids, sludges, and varnishes. The weak acids can be titrated by Total Acid Number (TAN) testing and, when quantified, give an indication of the degree of oxidation of the oil. The approach of detecting and analyzing sludge and varnish problems in machinery is not the same as that used in oil analysis. In many instances this is because the evidence is not always in the oil. The sludge and varnish should be analyzed directly, using a completely different set of tests and evaluation parameters. Still, used oil analysis plays an important diagnostic role in helping to reveal candidate causes, as well as to rule out others. The conditions that commonly lead to sludge and varnish problems vary, which complicates the process of identifying the root cause analytically. There are at least 25 unique lubricant degradation mechanisms leading to sludge or varnish formation. A few of these include: •

Aeration of the fluid

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Sparking from static electricity

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Bulk thermal degradation

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Anti-freeze contamination

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Soot coagulation

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Bulk oil oxidation

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Hydrolysis

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Prolonged cold storage

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Grease-contaminated oil

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Caustic detergent contamination

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Nitration

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Coking on hot surfaces

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Radiological contamination

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Poor engine combustion efficiency and blow-by

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Highly aromatic fuels

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Sulfation (fuel, H2S, and so on)

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Lead corrosion reactions

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Reactive compressor gases

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Additive incompatibilities

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Base oil incompatibilities

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Upon reviewing the previous list, it is obvious that the prescribed corrective action relies on the accurate discovery of the specific, and often elusive, root cause. Without this, correcting the problem is reduced to the costly and lengthy process of trial-and-error. It is always good advice to keep an accurate history of the conditions and observations that lead up to the occurrence of sludge and varnish. The troubleshooting process depends on building a case file containing each little piece of information and a timeline. Lubricants degrade in different ways and the products of this degradation are essentially referred to as sludge and varnish. These products are generally unstable in the oil and, as such, are looking for a place to land (that is, to deposit themselves). In certain instances, the deposits form on machine surfaces at the exact location where the oil has degraded, for example, hot surface coking. In other cases, the oil degrades in one location but deposits condense on a surface elsewhere. Over time, some deposits can thermally cure (become baked on) to a tough enamel-like coating. Other types of deposits, generally in cooler zones, remain soft or gummy. Sludge is not always black or even dark. It may appear clear and grease-like, similar to petroleum jelly. The following are examples of where and how sludge and varnish might occur: •

Black crusty deposits on mechanical seals

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Gold adherent films on spool valves in electro-hydraulic control (EHC) systems

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Charcoal-like deposits on babbitt sleeve bearings

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Gooey-brown mayonnaise-like gunk on diesel engine oil filters

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Black scabby deposits on thrust-bearing pads

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Lumpy, tar-like globs in dryer bearing drain lines (paper machine)

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Grayish gummy deposits on natural gas engine discharge ports

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Carbonaceous residue of servo strainers

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Hard black enamel on piston crown and ring lands

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Cottage cheese-like gunk clinging to engine valve covers

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Drab-color slime on compressor oil filters

The deposits that form on machine surfaces interfere with the reliable performance of the fluid and the machine’s mechanical movements. They can also contribute to wear and corrosion or simply cling to surfaces. For example, deposits on the spool of a servo control valve can tighten the interference fit between the spool and the bore. Compounding this are the adherence properties of varnish, which can stick particles from the oil to silt lands, thus leading to common silt-lock valve failure. Other types of sludge and varnish-type failures include plugged orifices, damaged mechanical seals, plugged discharged ports on compressors, journal-bearing failure, premature plugging of oil filters, and diesel engine combustion-zone wear.

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Contaminant Elimination Eliminating contaminants typically involves some kind of mechanical separation of the contaminant from the oil. Filters are the most commonly thought of tool to remove contaminants. The effectiveness of particular filtration or other separation techniques are dependent on accurately identifying the source, nature, and cause of the offending contaminant. For each of the identified contaminant types, the strategies and tools for eliminating them from the lubrication system are discussed. Particulate In addressing particulate removal, it is first necessary to review each machine to determine the design features that remove particulate. Nearly every lubricated machine includes a sump of some sort that serves to hold the lubricant until it is provided to the lubricated parts. Due to its design, the sump (with regard to its volume and flow rate) is often inherently a particulate removal location. As the velocity of the lubricant diminishes in the sump, the particulate returning from the lubricated parts is able to come out of suspension and settle on the sump floor. Over time, this settled particulate can accumulate and reach a level where it is reintroduced to the oil flow. It is important that sumps be kept from accumulating excessive particulate by periodic cleaning where needed. Many reservoirs will also include a continuous filtration system as part of the design. This can either be in-line to the lubricant flow, at the supply or return lines, or in a kidney-loop arrangement off to the side of the reservoir (as shown in Figure 5-6). In either case, it is important that these original design features be properly maintained. Figure 5-7 shows a typical filter and housing and illustrates the checkpoint areas. Always compare the replaced element with the one removed. Many manufacturers make interchange elements or purchase elements from each other and, in some instances, vendors may cross-reference part numbers. Errors can be made when the wrong element is provided for replacement.

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Figure 5-6 Continuous Filtration Machine

Figure 5-7 Filter Operation Checkpoints

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Always replace the filter seals with the new seals that come with the element. If replacement seals are not available, visually check to make sure the existing seals are in good shape. Seals are there for a reason—to make sure the oil goes through the filter and not around it. In multielement assemblies there is usually a seal between the elements as well. Bypass assemblies should be visually inspected and periodically cleaned and resealed. Indicators should be checked at intervals to make sure they are functioning properly. Reviews of the systems being filtered should be conducted annually to verify components and to ensure a proper level of filtration for any new or modified components. Other methods of particulate removal include electrostatic precipitation and centrifuging. Most power plants were built with centrifuges in place to clean particulate and moisture from turbine oils. These units are notorious for high maintenance costs and are frequently found in a state of disrepair. More modern filtration technologies have eclipsed the use of centrifuges, and most power plants have converted to high-efficiency filtration and coalescing technologies for treating turbine oils. A best practice that has received widespread use in the power generation industry is the upgrading of original centrifuge systems for turbine oil filtration. Many plants have seen significant quality increases in their turbine oil supplies by incorporating high-efficiency filtration and coalescing technology to maintain a constant turbine oil purification loop. An example of these units is seen in Figure 5-8.

Figure 5-8 Turbine Oil Purifier

Supplemental filtration is another example of contaminant reduction options. Often, the installed particulate removal methods, or water removal methods, are inadequate to either keep up with non-design environmental factors, or are of a vintage or quality that did not provide adequate barriers in initial design. The use of supplemental filtration systems can be extremely effective when deployed in response to increasing contaminant trends. 5-17


Numerous different filter media and separation mechanisms are available for removing particles. The performance of these devices is typically evaluated according to the following performance criteria: •

Filter stability How stable is the filter’s performance over time? Unstable filter performance equates to unreliable contamination control. Many factors influence filter stability including temperature variation, cold-starts, pressure surges, and mechanical vibration. The filter’s size, design, and construction influence its stability.

•

Filter capacity This describes the amount of test contaminant a filter can remove, typically in grams.

•

Beta Ratio/Filter efficiency How effectively does a filter remove particles of a given size? This is important information in assessing a filter’s ability to meet the machine’s cleanliness requirements. It is also important to assess the total cost to filter the oil.

The Beta Ratio is the result of the ISO 16889, Multipass Test Procedure. This procedure calls for the release of contaminant upstream of the filter. As the contaminant is circulated through the element, pressure drop and particle counts are monitored in a controlled manner. This test will not only determine the size of the particle that the element will remove, but also its dirt-holding capability and efficiency at different pressure drops. The Beta Ratio is nothing more than a number of particles of a specific size counted prior to the filter, divided by the number after the filter (as shown in Figure 5-9). This gives an indication of the element’s efficiency. An element with a Beta Ratio of 2.0 at 10 microns would only be 50% efficient; a Beta Ratio of 20 is 95.0% effective. A Beta 10 of 75 will remove 98.7% of the 10-micron particles, while Beta 200 is only 99.5%. As the number gets higher, the effect is not as great and will depend on the measuring equipment used. Except in return-line applications, a jump from Beta 75 to 200 may not be worth the expense of the element. Any number greater than 100 adds less than 1% to the overall efficiency. The system’s needs are the best determining factor. Do not forget to evaluate the dirtholding capacity of the element. One manufacturer’s element may have the same Beta value as another, and be equal in price, but will hold more debris.

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Figure 5-9 Determining Beta Rating

Filter Media •

Cellulose fiber media filters Available in cartridge or spin-on configurations, these filters are equipped with a paper-based (from wood pulp) pleated media. These filters are generally effective at removing larger particles but often lack performance in the removal of silt-sized particles. Paper media is subject to damage caused by water and high temperature.

•

Micro-fiberglass media filters Also available in cartridge or spin-on configurations, the performance of micro-glass media filters is typically superior to cellulose fiber filters due to small fiber strand diameter, higher pore density, and smaller average pore size. These filters can remove most large particles and many smaller, silt-sized particles from the oil. They offer superior thermal stability and are generally unaffected by the presence of water.

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Filter Location Options Suction filters are designed to protect the lubricant/hydraulic pump from fluid contamination. This style of filter has lost acceptance as systems have become more and more involved. They tend to be the least effective of all filters because they depend on the suction generated by the pump. If installed incorrectly, this filter can lead to pump cavitation (starving the pump of fluid) and can actually contribute to the wear chain. Inlet strainers (usually of wire mesh construction) are located in the oil reservoir and catch primarily the rocks and rags that can get left in tanks during filling and overhaul. It is a better idea to keep the reservoir as much of a closed system as possible. Use efficient air breathers and always filter new oil into the reservoir. Never leave this portion of the system open to the environment. Pressure filters are located after the pump and are designed to handle full system pressure. There can be a number of these filters located throughout a hydraulic system and each can be specific to a particular component in the system. This is a good idea and is inexpensive insurance against the failure of very expensive components. Return-line filters tend to be the most common filters in use on hydraulic systems. Easy to apply and lower in cost than pressure filters, they capture all of the system debris before the oil is returned to the reservoir. Currently, a great deal more in-tank return filters are being used. This approach can further reduce overall system size and eliminate piping. Off-line filtration is an auxiliary form of filtration. This tends to be a stand-alone system separate from the other filters. It may meter a portion of the fluid flow through elements to increase the level of filtration, or it may have its own pump to transfer oil from the reservoir, through the element(s), and back into the system. This is the style of filtration that is the most flexible. It can be used to “polish” the fluids (that is, to clean them finer than the system filter is able). These filters can be used to quickly remove gross contamination after a catastrophic failure or to transfer replacement lubricant into the reservoir. Because equipment does not need to be shut down to use these filters, they allow a large amount of flexibility in choice of elements. The same system can be used for water removal, compressor lube filtration, gearbox filtration, even coolant conditioning just by changing the elements. A best practice is to dedicate such units to a particular service or lubricant type to avoid the risk of cross-contamination. An off-line filtration system, properly engineered, can meet all of the following requirements: •

It can be used to filter the first full tank of fluid to the desired cleanliness level before the main system pump is started. This is shown in Figure 5-10.

•

The off-line system is not only capable of achieving a low level of contamination but, by using this system for topping-up, it can eliminate the dangers inherent to the normal methods of adding fluid.

•

Changes of element do not involve touching the main system, so the very minimum of service skill is acceptable.

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•

Being independent of the main system, filters can be placed where they are most convenient for servicing.

•

The effect of filter change indication during high-pressure surges at cold start can be greatly reduced.

•

Maintenance can be carried out at any time without stopping or introducing air into the main system.

•

By optimizing flow through the element, the maximum debris-holding capacity of the particular element can be fully utilized.

Figure 5-10 Filtered Machine Fill

In addition to meeting these requirements, an off-line system can be used for initial filling and partial flushing of the main system. If the system is left running continuously, it provides a complete tank of super clean fluid ready for every startup. The system will continue to clean up the fluid when variable delivery pumps are running at minimum displacement, and it could be used to supply cool, clean oil to their casing under this condition. Water In addition to filtration, other options exist for contaminant elimination, including water coalescence, centrifuging, tank settling, and vacuum dehydration. Each of these methods must be evaluated based on its own merit, to provide the most efficient and effective method of removal at the most reasonable cost of purchase, maintenance, and operation.

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•

Gravity Separation Because water generally has a higher specific gravity than hydraulic fluid (exceptions do exist), water tends to settle at the bottom of the reservoir if given sufficient resident time in a still environment. Increasing the temperature of the fluid and employing a cone-shaped separating tank, improves the effectiveness of gravity separation. High fluid viscosity, oxidation byproducts, and polar additives and impurities inhibit the effective separation of oil and water. Gravity separation alone does not remove tightly emulsified or dissolved water.

•

Centrifugal Separation By spinning the fluid, the difference in specific gravity between the fluid and the water is magnified. Centrifugal separators remove free water faster than gravity separators. They also remove some emulsified water depending upon the relative strength of the emulsion versus the centrifugal force of the separator. Centrifugal separators do not remove dissolved water. They are an excellent option for continuous decontamination of fluids, with excellent demulsibility (water separating characteristics).

•

Coalescing Separation Coalescing separators help small droplets of water combine to form large ones so they will drop out of the oil more easily. This is achieved because large droplets have less surface contact with the fluid than an equal volume of water dispersed as tiny droplets. Coalescing separators are more effective when the viscosity of the oil is low, making them an ideal solution for removing water from fuel and turbine oils. Coalescing separators are not effective at removing dissolved water.

•

Absorbent Polymer Separation Free and emulsified water is collected by super-absorbent polymers impregnated in the media of certain filters. These look like conventional spin-on or cartridge-type filters. The water causes the polymer to swell and remain trapped in the filter’s media. Super-absorbent filters can remove only a limited volume of water before causing the filter to go into pressure-dropinduced bypass. They are not well suited for removing large volumes of water but they are a convenient way to maintain dry conditions in systems that do not normally ingest a lot of water. These filters do not remove dissolved water.

•

Vacuum Distillation This technique effectively removes free, emulsified, and dissolved water. Vacuum distillation units operate by distributing oil over a large surface area and by, effectively, boiling the water by increasing the temperature to approximately 150°F to 160°F (66°C to 71°C) and creating a vacuum of about 28 in. (71 cm) Hg. At 25 in. (63.5 cm) Hg, water boils at approximately 133°F (56°C). These devices effectively remove water at a temperature that does not cause much damage to the base oil or additives. Vacuum distillation will also remove other high vapor pressure contaminants such as refrigerants, solvents, and fuels. There is some risk of additive vaporization with this technique.

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•

Headspace Dehumidification These units operate by removing air from the headspace of a sump, dehumidifying it, then sending an equal volume (or a boosted volume, in some cases) of air back to the reservoir to maintain pressure. If the oil contains water contamination, it will migrate to the dry air, which is eventually sent to the dehumidifier for removal. The great advantage of this technique is that it never contacts the oil. This technique will remove free, emulsified, and dissolved water.

Glycol, Fuel, and Soot These contaminants cannot be effectively removed by mechanical means and their presence at unacceptable levels requires an oil change to be performed. Their presence is typically only seen in internal combustion engine systems, which require periodic oil changes anyway. However, if their concentration is seen in values that are unexpected, and early in the cycle of regular oil changes, then the root causes of their presence must be determined to prevent recurrence of contamination. Also, their presence is generally indicative of other mechanical problems with the engine and a thorough investigation of the operation of the engine should be performed. In particular, the presence of glycol should prompt investigators to focus on the areas of interface between the coolant and the oil, such as gasket areas and heat exchange interfaces. Fuel contamination points toward fuel injector problems and cylinder wall or ring issues. Excessive soot may raise questions about fuel quality or ignition conditions. All of these contaminants should be addressed by investigating the fundamental sound operation of the engine and should be accompanied by available engine diagnostic testing. Air When reviewing a system to determine causes of foaming and air entrainment, start at one end of the circulating system and follow the fluid flow around the circuit, watching for areas where bubbles could be generated. In particular, look for air leaks on the suction side of a high-pressure oil pump, or for working elements that may churn the air into tiny bubbles. Reservoir design plays a significant role in controlling foam and air entrainment. Keeping the reservoir inlet below the surface of the fluid to prevent splashing is an obvious way to prevent foaming. If this is not possible, install an angled plate so that the oil gently slides into the reservoir. Also effective is a wire screen (60 mesh) that acts as a nucleation site for bubbles and prevents foam from entering the outlet (suction line). Scavenger pumps often mix large amounts of air into the fluid. Instead of keeping the inlet below the level of the fluid in the reservoir, raise the inlet so that air has time to dissipate before it reaches the bulk oil. Figure 5-11 shows a number of options to minimize the formation of air bubbles in a reservoir return. If the inlet is too close to the outlet, install baffles or wires to increase residence time. Maximize the surface area and residence time in the reservoir, and make sure that the oil level is high enough to prevent the exiting oil from creating a vortex and sucking air. Make-up oil should be added to a sump through a hose extended below the surface of the fluid to minimize splashing. 5-23


Figure 5-11 Reducing Air Problems in Oil Reservoirs

Loose fittings on the suction side of a pump can be a common source of air. It is easy to check for leaks by coating the fittings with foamy shaving cream and watching for dimples. Very often there will be a number of leaks, so it is important to perform this test over all of the points where air may enter the system. Filters generally do not contribute to foam, although one study showed that synthetic fiber filters could remove anti-foam additives (although this is generally not an issue). Filters that are plugged and in a bypass can allow particulates to pass through the system, which can exacerbate foam formation. Watch for and avoid silicone impregnated filter media when foaming is an issue. Entrained air may explain a filter that appears to be plugged when there is no sign of physical contamination. Bubbles are surrounded by a sheath that has relatively high surface tension. These bubbles can block a filter and then disappear when the filter is dismantled for inspection. Sharp bends in piping can cause a pressure drop that pulls dissolved air out of solution. The same phenomenon can occur if there is a dramatic increase in the diameter of a pipe. Make sure that fluid conductors are properly bled and evacuated prior to startup. Also, check for leaks around valves and sharp bends or areas of turbulent flow. One field problem with foam was caused by oil flow through a bearing. The oil was forced to make a 90degree change in direction as it exited the bearing. Chamfering the internal edges solved the problem.

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The working elements can beat air into the bulk of the oil if the level is too high, and they can churn foam onto the surface if the level is too low. Check sight gages regularly and adjust flow rates to ensure optimum oil levels. Lower the outlet if it is too close to the surface. Turbine thrust bearing wear can be caused by dissolved air coming out of solution. One guide recommends using a positive pressure of 0.7 bar for turbine thrust bearings to avoid this problem. Some equipment inherently foams. Electric motors may foam if they are mounted vertically but not if they are mounted horizontally. The equipment manufacturers can usually indicate if their equipment has a tendency to induce foaming more if mounted in one configuration or another. When diagnosing foam problems, it is important to use a systematic approach to discover the root cause of foam and air entrainment problems. First, determine whether the air-in-oil problem is foam or if it is actually air entrainment. After that, look at the overall system, the fluid, and the components to eliminate the sources of air problems. Avoid treating the symptoms rather than the cause. If it is necessary, however, the use of aftermarket anti-foam additives can, in some circumstances, resolve the problem, provided that all other influencing conditions have been addressed. Oxidation Products It is a good maintenance strategy to remove oxidation products as they are produced, before they build up within the system. One option for removing insoluble soft contaminants is electrostatic separators. This process is being used more as a solution for varnish- and sludge-related reliability problems. Electrostatic separators work on the condition that mineral, synthetic, and vegetable oils have low electric conductivity and dielectric constant. Also, most insoluble contaminants suspended in oil have polarity or electric charge, regardless of their size or composition. By passing an electrical current through the oil, these contaminants can be removed by electrostatic precipitation onto collection plates or other suitable media as shown in Figure 5-12. The process has been reported to remove single contaminants less than 0.05 microns but, more importantly, it allows the oxidation products to agglomerate. This method of separating contaminants has been shown to effectively remove oxidation byproducts, silt-sized particles, and used additive floc. Tests suggest that it does not remove active, dissolved additives.

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Figure 5-12 Electrostatic Precipitation

Ion-exchange media have been used successfully to remove the oxidation products in phosphate esters, the product used in EHC systems. Because phosphate ester degradation products are water-soluble, ion-exchange resins are able to remove these types of products. Reductions in TAN values, and increased conductivity values, have been experienced by power plants using an ion-exchange technology filter skid in the treatment of aged EHC fluid. Specially designed cartridges of the type shown in Figure 5-13 have been designed to hold the resin material and enable it to be retrofitted into standard turbine EHC filtration housings. A number of power plants have reported significant savings in EHC fluid costs and EHC system performance increases with the use of ion-exchange technology.

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Figure 5-13 Filter Cartridge

Contaminant Exclusion The proactive aspect of contamination control is in taking steps to eliminate the ingression of contaminants in the first place. Many of these strategies have been mentioned throughout this guideline (in Section 2, “Standards, Consolidation, and Procurement,” Section 3, “Storage and Handling,” and Section 8, “Lubrication/Relubrication Practices”). These include: •

Resealing new drums after sampling for receipt inspection.

•

Maintaining the cleanliness of bearings, seals, and gears during storage.

•

Storing drums/totes out of the weather, and identifying and removing leaky containers.

•

Properly venting storage containers to exclude particulates and moisture.

•

Minimizing funnels and maintaining cleanliness of grease guns and other lube tools.

•

Using transfer carts to pre-filter oil charges.

•

Observing shelf life and stock rotation principles.

•

Using appropriate top-off and transfer containers. Appropriate and inappropriate containers are included in Figure 5-14.

•

Testing and reconditioning top-off and transfer containers.

•

Employing proper procedures for draining and flushing sumps and reservoirs. 5-27


Figure 5-14 Transfer Containers

A critical strategy in excluding contaminant from lubricants takes place at the machine itself during operation. Every machine breathes during operation, and particularly during startup and shutdown. To prevent ambient dust, dirt, and moisture from entering the lubrication reservoir, machines should be designed to provide limited access to the surroundings. The idea is to seal the reservoir and the lubrication path from the environment, and to provide a filtered pathway for the machine to breathe. Sealing the Machine Shaft Seals At the locations where shafts exit the reservoirs and are exposed to the ambient environment, there can be a significant opportunity to take in contamination. From water that is introduced by leaks and pump seal failures, to general area dirt and coal dust, every effort must be made to seal these openings. Many machines in use in power plants are provided with lip seals that ride in contact on the shaft. Although these types of seals generally do a good job at keeping the lubricant in, they can degrade with time and compromise protection from external contaminants. In extended service, lip seals have a tendency to wear grooves on the shaft, which opens pathways for contamination. Another option is the use of rotating labyrinth seals as shown in Figure 5-15. Although more expensive initially (and they must be carefully designed for each application), these seals provide better protection and are more economical in the long run.

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Figure 5-15 Labyrinth Seal

Lids, Access Ports There are many joints and interfaces in a bearing housing or reservoir. Routine equipment inspections should include the identification of damaged components that can allow contaminants to enter as shown in Figure 5-16. In larger reservoirs, there are man-ways and access ports. By design, most equipment should include gaskets and seals for these openings. In practice, it is not uncommon to find such hatches poorly sealed with degraded gaskets, slightly open to accommodate tubing or hoses, or even left open deliberately in a misguided attempt to cool the oil. In the image shown in Figure 5-17, the personnel in this plant purchased and installed a new filtration skid to address their contamination problems. However, they tied the skid in by opening the hatch and dropping the return hose in. The top was littered with debris and absorbent clay, which was continually dropping into the open hatch and no doubt overwhelming anything that the new skid could filter out.

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Figure 5-16 Missing Screws on Sight-Glass

Figure 5-17 Open Hatch

One should not rely on a filter to be a catch all. For any cleanup effort to be successful, the source of ingression must be found and halted at the same time, or prior to, installing supplemental filtration. Figure 5-18 shows how modifications made to this reservoir hatch have compromised its ability to exclude contaminants, which can now freely fall into the reservoir.

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Figure 5-18 Modifications to Hatch

Keeping Out Water Water has several pathways by which to enter oil reservoirs. Leaks of internal coolers are a common condition that can introduce a major amount of water in a short period. Blown pump seals, in certain designs, can dump the water directly into the bearing and back to the reservoir. Also, unattended steam leaks on turbine reservoirs can turn a hatch into a “rainmaker,” as illustrated in Figure 5-19. In these cases, careful monitoring of the moisture levels must be accompanied by proper preventive and corrective maintenance of the interfaces, including cooler pressure testing and seal condition checks during overhauls. Even small increases above an otherwise low, steady moisture level can be indicative of early stage failure of seals or coolers.

Figure 5-19 Turbine Reservoir Hatch

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External pathways include ingestion from local leaks, normal machine breathing, temperature differential condensation, and steam or process fluid intrusion. Water should never be used to cool overheating machinery by running a hose over a bearing or reservoir. Direct impingement of water on surfaces not designed for such exposure will inevitably result in water ingression to the lubricant. Whenever a steam or process leak is noted in the vicinity of an oil reservoir or lubricated bearing, it should be corrected at the earliest convenience and temporary shielding measures should be taken in the meantime. In situations where chronic moisture levels are experienced, or corrective measures are challenging or not forthcoming, special efforts to minimize moisture concentration must be taken. They can include the establishment of an on-line vacuum dehydration unit, air stripping of moisture, or blanketing the headspace of the reservoir with a dry gas. Filtering the Vent Breather Filters Breather filters are a simple and extremely cost-effective way to minimize the ingestion of contaminants, once the reservoir or bearing housing has been sealed to a single vent. If multiple paths of air exchange exist, placing a breather filter on one opening will not be effective—the air will simply find the path of least resistance. Breather filters must be maintained and changed out periodically to ensure that they continue to provide a low-resistance pathway for clean incoming air. Figure 5-20 shows the installation of a breather filter on a large gearbox that is also fitted for supplemental filtration with a portable cart. Where needed, such a reservoir can be fitted with a fill/drain device at the vent to allow constant filtered ventilation when using a single access point for oil circulation return. In cases where no vent is available, or the fill cap has holes to serve as a vent, a filter breather can be fitted for the fill cap thread and placed at that position. This arrangement is shown in Figure 5-21. When access through the fill hole is needed, the filter breather can be spun out to provide that access.

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Figure 5-20 Filter Breather

Figure 5-21 Desiccated Filter Breather

Desiccant In areas where ambient moisture is a problem, desiccated breather filters should be used. They can be purchased with color-indicating media to simplify the scheduling of change-out. Understanding the construction and design of the breather can also help in the troubleshooting of 5-33


quickly depleting desiccants. If the color change progresses from the outside pathway in, then there is an excessive source of moisture contamination in the machine ambient. If the color change progresses from the inside out, then there is reason to expect that the moisture is being internally generated, perhaps from a seal failure, cooler leak, or other internal source. Desiccants must be monitored and serviced. Some plants that have implemented a program of desiccated filter breather use have also dedicated an oven for reclaiming the desiccants. Although this can save on new purchase expenses, be sure to recognize when the desiccant capacity has diminished and requires replacement. Bladders and Expansion Chambers In extreme cases of very high ambient moisture or particulate levels, it may be necessary to totally seal the reservoir from the ambient environment. In this case, it is still necessary to allow the machine to breathe and this is done with the use of expansion chambers. Figure 5-22 shows how these devices function. In selecting this option, it is important to know the design parameters of the area being sealed, so that acceptable pressures will not be exceeded with the use of the expansion chambers. When properly designed, these devices can provide protection to equipment in the most aggressive contamination environments, and help to extend lubricant and machine life.

Figure 5-22 Expansion Chambers

Every machine needs to be assessed for the possible pathways of contamination. If there is an unprotected opening, it can be assured that contaminants will eventually find their way in. Even when aggressive filtration is in place, the level of ingested contaminants must be kept as low as possible to gain maximum life and reliability from the lubricated machinery. 5-34


6

TRAINING, SKILL STANDARDS, AND CERTIFICATION

A world-class lubrication and lubricant analysis program requires individuals with world-class skills. Although it is true to say that those directly responsible for lubrication must be properly trained, other individuals in the organization also require knowledge, or at least an awareness, of the program’s goals, primary benefits, and fundamental tenets. In order for the organization as a whole to succeed in lubrication excellence, it is vital that a lubrication and lubricant analysis skill development program be put in place and be tailored to meet the needs of all individuals who have responsibility for lubrication tasks, or that may have input into the lube program.

Lubrication Training Almost everyone in a plant needs some lubrication awareness training. The lubrication topics selected and the degree to which they should be covered depend upon the individual’s job responsibility. For example, it doesn’t make sense to put the plant manager through a detailed training program on the use of a grease gun. That is simply not a skill the plant manager is going to use. Although this is a good example, which is generally applicable, each plant or company needs to develop its own specific lubrication training objectives based on its different staff categories. As another example, it is not necessary for the vibration specialist to attend a detailed lube oil training program; however, that person should be sufficiently aware of the plant lubricant program to determine interactions between the two technologies. The skill inventory and training program will vary from organization to organization. As an illustration, consider a plant with the lubrication-related job descriptions shown in the skill-based matrix of Figure 6-1.

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EPRI Licensed Material Training, Skill Standards, and Certification

Figure 6-1 Example of Skill-Based Matrix

Reliability and PdM Analyst This skilled individual is responsible for ensuring the reliability of the plant and is the primary technical resource to the plant on maintenance and reliability issues. His or her role is to run on-site oil analysis tests, assimilate and evaluate data from both on-site and off-site oil sample analysis, and to interface with the other reliability team members from the vibration and thermography groups. To provide this support, the analyst requires a thorough understanding of all of the functional skill areas of lubrication and oil analysis. To achieve the desired level of knowledge for this position, the individual typically needs several weeks of training on the basics of lubrication and lubricant analysis. It may also require extensive training on various procedures for which that person will be responsible (sampling for example). In addition, extensive specialized training is required on the correct use, maintenance, and calibration of on-site test equipment. This individual also requires frequent training to keep knowledge and skills up to date and should be actively involved with appropriate conferences and meetings to hone skills, make contacts, and benchmark best practices. Lubrication Technicians These individuals are primarily responsible for lubricating the machines. They manage the storeroom, grease bearings, top-up machines, perform oil changes, make or support decisions to upgrade or change a lubricant specification, and/or reengineer or upgrade lubricant application hardware. They work with lubricant suppliers and lubrication consultants daily to keep things going smoothly. They also manage contamination control efforts by maintaining breathers and filters, using filter carts and other periodic decontamination technologies, and so on. Lube technicians work closely with mechanics to troubleshoot machine problems that might be lubrication-related. Lube technicians require a thorough understanding of lube storage and handling, lubrication fundamentals, and contamination control.

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Lube technicians require several weeks of training to develop a sturdy knowledge base. Additional time is required to train the individuals on various procedures with which they will be working. It is not sufficient to rely solely on hands-on training from experienced technicians because a small procedural mistake, often made as a perceived timesaving exercise, can perpetuate and grow into a major flaw in lubrication best practices. As with the reliability technician, these individuals will also require frequent booster shots to keep their skills fine-tuned and current. Oil Analysts Whether they are tasked to perform the analysis function with a mini-lab, or are part of a fullscale oil analysis laboratory, the lab analysts must have specific lubricant analysis knowledge and a general understanding of how their results and findings will affect decisions at the plant level. There are a few on-site full-scale oil labs at U.S. power plants; however, the majority uses a central corporate lab, a mini-lab, or sends their samples to a contract laboratory. Unfortunately, in some settings, the analysts performing oil analysis are viewed as just performing another chemistry function and may operate wholly within a more comprehensive wet chemistry laboratory. Unless the analysts and lab managers learn about the specific challenges and the unique use of oil analysis data in making machinery prognostics, the opportunity to provide effective and insightful recommendations from the analyst level may be lost. When a full-scale laboratory is in place at the plant, or at a corporate central facility, it is advisable to adopt training certifications such as the Society of Tribologists and Lubrication Engineers (STLE) Oil Monitoring Analyst II (OMA-2) or the International Council for Machinery Lubrication (ICML) Laboratory Lubricant Analyst (LLA) programs. For on-site mini-labs, Oil Monitoring Analyst I (OMA-1) or Machinery Lubricant Analyst (MLA) certifications are likewise appropriate. Ensuring the appropriate skill levels at the analyst level will result in increased confidence in the quality of the analyses performed, and will typically result in much more meaningful and insightful recommendations for action in the sample analysis reports. Mechanics Mechanics are most intimately familiar with the internal workings and condition of the plant’s machinery. They need sufficient technical knowledge about lubrication fundamentals to spot and accurately diagnose lubrication-induced abnormalities and opportunities to reduce wear through changes in the lubricant type, delivery mechanism, or maintenance. If they fail to provide feedback about the effectiveness of the lubrication process, the same problems will recur. They also need to understand the importance of maintaining or restoring cleanliness during repair, and to be proficient in procedures for doing so. Because the mechanics are sometimes asked to perform oil changes, they must be trained on those procedures.

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Operators Operators see more of the equipment than anyone in the plant and are typically required to walkdown the equipment every shift. This is a great opportunity to collect simple, inspection-based lubrication information. Beyond the level gages, the operators should regularly inspect for filter and desiccant condition, evidence of water contamination, foaming and air entrainment, leaks, darkening of the oil, sludge, smoke or fumes exuded from vents, and a host of other easy-toobserve conditions. Operators should be set up with a clipboard, or preferably a digital personal data assistant (PDA), which allows them to input inspection information using questions to which they can simply answer yes, no, or not applicable. This information must be fed back to the lube technician and reliability analyst so that appropriate corrective action can be taken. The operators must also be trained to perform these functions, with an occasional refresher course to bring their skills and knowledge back up to speed. Managers and Supervisors Although they need only awareness training, management training is typically the most important, but most commonly overlooked, training in the program. Managers make resources available, provide visibility for the program, and must defend it when it comes under fire. Managers require very little skill-oriented training (sampling procedures for example), but they need some technical knowledge about the various aspects of the program (such as why a representative sample is important to oil analysis effectiveness), and they should have a general knowledge about how good lubrication management creates value (like high particle count in the fluid increases wear and clean oil reduces costs). The emphasis for management is on the financial benefits that the program provides, on the aspects of managing the lubrication team, and on providing the resources required. Managers and supervisors need up to one day of intensive awareness training, along with periodic information updates to keep them fresh and current with regard to new information. Conferences serve as a good maintenance knowledge mechanism for managers. At these events, they can discuss lubrication program management issues with their peers, attend benchmarking sessions, and become exposed to new products, technologies, services, procedures, and best practices.

Knowledge and Skill Certification Having selected the appropriate training modules, the question that must be addressed is, “How does management know that an individual can perform a particular job?” The answer to this is certification. Certification ensures that an individual possesses the knowledge and skills to perform the required tasks. Knowledge certification is fundamental to success and is best performed by a third-party entity. A third-party entity is truly objective in that it has no stake in the success of the organization or the individual. Another advantage of third-party certification is its transferability. An 6-4


organization can hire a person pre-certified and individuals can take their certifications with them. If a non-pre-certified individual is available for a position, certification within a certain timeframe can be made a condition of employment. Third-party certification relieves managers from the requirement of possessing expert knowledge on the topic in order to evaluate an individual’s capabilities. In today’s plants, managers are spread very thin. They can’t be experts on everything. As long as the managers know who the experts are and where they can be found, they don’t have to be experts themselves. In the lubrication industry, the STLE and the ICML, both non-profit organizations, serve in this capacity. STLE has certification programs for Certified Lubrication Specialist (CLS) and Oil Monitoring Analyst (OMA-1 and OMA-2). ICML offers multi-level skill certifications for the Machinery Lubrication Technician (MLT), Machinery Lubricant Analyst (MLA), and the Laboratory Lubricant Analyst (LLA). In the STLE, the Oil Monitoring Analyst I (OMA I) exam is designed to test and document the knowledge of an individual who conducts first echelon oil monitoring and analysis, as it applies to lubrication analysis and machine condition monitoring. The emphasis of this exam is the routine operation of an oil analysis program. The areas covered include Basic Mechanical Systems, Oil Sampling, Basic Lubricant Properties, Basic Analytical Methods, Basic Data Analysis, and Basic Corrective Actions. The Oil Monitoring Analyst II (OMA II) exam is designed to test and document the knowledge of an individual who conducts second echelon oil monitoring and analysis. The emphasis of this exam is the design, implementation, control and management of an oil analysis program. The areas covered include Program Design, Implementation, and Control. The ICML certification programs break the lubrication training function down into three distinct areas of practice. Generally speaking, these are meant to reflect the different types of job positions requiring skill certification. They include the lubrication technician, a machinery lubricant analyst (generally a plant-based individual responsible for the lubricant analysis program), and the laboratory analyst (typically responsible for analysis of delivered samples at a remote laboratory location). Figure 6-2 summarizes the skill evaluation objectives for each of ICML’s certifications at two levels. In keeping with the concept of establishing a training matrix of required certifications for given plant tasks, the required certification for each lubricant job function is outlined in Figure 6-3.

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Figure 6-2 Skills Evaluation

Figure 6-3 Required Certification for Job Functions

On-the-Job Training (OJT) On-the-job training is a required and traditional aspect of many areas of skill development. In the maintenance area, most of the skilled trades are traditionally dependent upon a system where seasoned mechanics are partnered with novices to ensure that the newly trained and relatively inexperienced technicians are given the chance to observe an experienced staff member under many circumstances of work performance. These apprentice positions are traditionally designated to last for significant periods of time before the technician becomes certified to be able to perform those tasks independently. In lubrication activities and oil analysis, much of the same approach is necessary to ensure that machines are being properly lubricated and that oil sampling and analysis is performed to the high standards necessary to ensure meaningful and accurate analysis data. The training requirements for lubricant technicians should include a set time of apprenticeship. This time 6-6


would allow for observed and graded performance under field conditions before the individual is able to independently perform the tasks of lubricating equipment, taking oil samples, or performing analysis. Developing machinery lubrication and lubricant analysis skills with occupation-oriented training to build knowledge, skills, and attitudes can go a long way toward ensuring that lubrication best practices are implemented and effective. By certifying individuals, the level of knowledge and skills attained is not only ensured, but also a sense of pride and commitment permeates the organization.

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7

LUBRICANT ANALYSIS

Oil analysis is commonly used as a diagnostic tool in most power generation facilities. However, the oil analysis programs at these sites frequently lack the proper setup and use of data that are needed to gain maximum benefit. All too often, oil analysis results are provided to the customer in a hard-copy format that promptly gets filed, never to be looked at again. In these situations, oil analysis provides little or no value and, therefore, becomes an exercise in futility. The interval between which samples are obtained and analyzed must be properly selected to allow analysis results to have the maximum impact on maintenance decisions. The selection of the various tests to be performed on a given oil sample must be customized to the equipment being analyzed, and must take into account environmental factors, equipment service, types of lubricant, parts lubricated, and so on. These concerns are addressed in the selection of equipment-specific test slates that assign the right tests to the right machines. Also key to the success of oil analysis is the action taken based on the analysis results; the focus on reporting and action is discussed in Section 9, “Program Management.” The first decision to be made is the determination of what type of analysis program will be used. There are essentially three options: an on-site full-service lab, an off-site contract or central corporate lab, or an on-site mini-lab, augmented by off-site analysis. Each of the options has its strengths and can be a good fit for the right company and plant. It is necessary for each plant, therefore, to make a determination based on their corporate goals and support, available resources, and specific analysis needs.

Determining the Case for On-Site Versus Outsourced Oil Analysis The benefits of on-site oil analysis include: timeliness of data, the ability to quickly verify abnormally high or low readings, control over calibration and accuracy, and the ability to screen samples prior to submitting them to a laboratory for more detailed analysis. There is a more important benefit of on-site oil analysis, which is its positive impact upon the maintenance organization. In a conventional contract-lab oil analysis program, samples are periodically drawn, packaged, and sent to the lab for analysis. Results from the lab are then mailed, faxed, or e-mailed to the technician. Upon review, the technician, perhaps lacking an understanding of the actual data on the report, immediately goes to the report’s summarized recommendations. These comments often advise the oil to be changed or to continue sampling as usual. The report is then filed, never to be viewed again. This type of oil analysis program sadly leaves a tremendous amount of value on the table.

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EPRI Licensed Material Lubricant Analysis

In contrast, a modern oil analysis program is much different. Technicians who are skilled in the area of oil analysis routinely sample machines in a meticulous manner to ensure that the samples are representative and uncorrupted. The data produced by the oil analysis is understood, thus resulting in targeted maintenance actions. The modern oil analysis technician realizes that oil analysis not only provides information about the health of the lubricant, but it also holds information about the health of the machine and its interaction with the environment. Oil analysis data are combined with knowledge about oil analysis technology, to arrive at targeted maintenance actions that ensure proper lubrication. This process proactively builds machine reliability, and combines with vibration analysis, thermography, and other technologies to paint a clear picture about the health of the machine. In the optimum oil analysis program, the data are managed in such a way that they can serve future decisions with the benefit of histories and trends. In the establishment of an oil analysis program, there are some fundamental issues that must be addressed in deciding what type of program is the best fit for a given facility. For example, some plants have chosen to invest in the manpower, equipment, and training necessary to establish a fully functional oil analysis lab at their power plant site. To do this, it is necessary to justify the significant initial outlay in capital and the sizeable ongoing budgeting requirements to support a fully functioning lab. Typically, such a facility will require the commitment of at least one or two full-time staff members to properly run the lab. These staff members are necessary to ensure such things as daily calibration checks, reagent preparation, shelf-life checks, and the routine analysis of any and all oil samples performed by the facility. The total number of samples analyzed must typically be large enough to justify this cost outlay for an on-site laboratory. Motivations for an on-site lab may include the desire for extremely quick turn-around times on analysis. Although many major contract labs will provide rush analysis, logistically, the quickest results obtained in common use are 24 to 48 hours from the time of sampling. For an in-house laboratory, the time from when the sample is taken to the results being provided can be as short as 2 to 3 hours, depending on the tests that are required to be performed and the availability of trained analysis personnel. Other advantages of having an in-house oil analysis laboratory include the ability of the analyst to incorporate other information about the equipment, the environment, and the particulars of that machine when providing analysis results. In a nuclear power plant, for example, the ability to turn around an oil analysis result in a number of hours may have applications that can be sufficient to justify the investment in on-site analysis capability. Some equipment operability determinations must be made in decisions that are on the order of hours or days. Oil analysis results can help in that determination and prevent a plant shutdown or other significant action, helping to justify the investment and operational costs of the on-site lab. When the sizeable investment required for establishing an on-site laboratory is not justified, an interim step may be more appropriate. Establishing selected analysis capabilities, or a mini-lab, may bridge the gap between the decision to fully outsource the oil analysis function to a contractor laboratory, and the in-house laboratory scenario. Such mini-labs are available in an integrated package from commercial providers. Many of these are compatible with other predictive maintenance tools and software packages. They can be used either as a screening tool 7-2


to determine the need to perform more advanced analysis by an off-site laboratory, or to prioritize the turn-around times required for analysis. In other cases, selected analysis capability may be chosen to support specific plant evolutions. An example of this may be the use of on-line, or portable on-line, particle counters to support oil purification or oil flushing activities. In power plants, oil flushes of the main turbine and other large equipment can often consume a significant portion of outage time. By making the oil flushing and oil purification processes condition-based as opposed to time-based, it is possible to optimize the amount of time spent and ensure that the clean-up process is progressing at an acceptable rate. This will be determined when filters are operating at diminished capacity or have been improperly installed and are ineffective at cleaning particulate. Ultimately, one can set the duration of oil flushes or oil purification evolutions to the amount of time it takes to achieve the preset required value of cleanliness. In other words, if two shifts had historically been dedicated to performing an oil flush of a main turbine system, perhaps as little as five or six hours can be spent, if that is indeed the time it takes to achieve the target cleanliness levels. Using the portable on-line particle counter also provides the additional benefit of being assured of the as-left values of cleanliness. Other tests commonly employed in selective on-site testing include moisture monitoring, viscosity checks, and even additive concentration monitoring. Some of these tests are relatively simple to use, require modest initial capital outlay, and lower the cost of ongoing maintenance. Examples include rolling ball viscosity comparators, and the use of simple tests such as hot-plate crackle tests for moisture, or small portable mini-chem kits. In addition to the portable particle counter, devices such as the Remaining Useful Life Evaluation (RULER) are used to monitor additive levels, both of incoming oils and in-service oils. When a plant has made a decision to fully outsource the oil analysis function, there are still significant technical decisions that need to be made to ensure maximum value for the process. Oil analysis is sometimes treated as a commodity and, as a result, the lowest achievable packageprice for a given set of basic tests is sometimes employed across the board to provide oil analysis capability with minimum outlay. Unfortunately, if these tests are not carefully selected to reflect the required monitoring characteristics for the oils and machines in question, the value of such a program may be questionable. However, in a facility where oil samples can be efficiently gathered, labeled, and shipped to a designated contract laboratory, and where care has been taken to establish appropriate frequencies, test slates, and reporting mechanisms, outsourced oil analysis can be an efficient and cost-effective method. Ultimately, costs and corporate commitment will be vital in making the decision to adopt inhouse capabilities or to outsource the analysis function. For companies with a centralized corporate laboratory, the decision may be a clear one. If the centralized lab is well staffed and has solid oil analysis capabilities, the opportunity to utilize their skills and exploit the economies of scale afforded by the central lab offering the service to multiple sites may be a logical costbenefit proposition. Admittedly, a full-service on-site laboratory almost never has full utilization of analysis capacity, and having such a lab service for multiple sites increases the efficiency of 7-3


the resource. The economic justification for a single-site on-site lab must typically include valuation of the benefits afforded by quick turn-around of samples and the increased analysis detail afforded by the proximity to the machines and processes. Mini-labs have become a more popular approach to gain some of the on-site benefits, without the more significant capital and ongoing operational costs associated with a full-service lab. Even with the use of a mini-lab, however, additional laboratory capabilities will be necessary to provide follow-up analysis and more detailed testing. The combination of a mini-lab, or a few selected on-site analysis tests, and an established supporting laboratory with clear procedures for use of those services, can be a cost-effective and capable analysis strategy.

Evolving from a Conventional Oil Analysis Program to a Modern One Education is one important aspect of success, as are skill competency assurance and certification. Management support is another critical element to success; without it, the program never gets off the ground. Institutionalizing oil analysis best practices, so that the program becomes a permanent part of the organization, is an important element of, and helps to ensure, continued success. On-site oil analysis plays a critical, but sometimes hard-to-define role; it catalyzes passion within the organization. Passion is driven by involvement and ownership, which are the things that make people want to go to work every day. When individuals are truly satisfied in their job, a breeding ground for passion is created, which may be the most important ingredient to success. On-site oil analysis produces a sense of ownership, which enhances job satisfaction and creates passion. Here are some reasons why: •

Reduced Seclusion Being an oil analyst is often a lonely job. Few organizations have more than one individual assigned to oil analysis in any given location. Because of its technical nature, few of the analyst’s co-workers really understand the job of the analyst. Sometimes the analyst’s contribution to the organization is questioned because of co-workers’ (or managers’) lack of knowledge about the subject. Unless the analyst is a natural teacher, it is difficult to explain why evaluating a few complicated reports is important to the organization. On-site oil analysis, however, is active and tangible. People are interested in seeing new gadgets with which their co-worker is working. The tangible nature of on-site oil analysis equipment facilitates and simplifies the explanation of oil analysis to co-workers. The more that others understand about oil analysis, the less secluded the analyst feels; therefore, knowledge increases confidence.

•

Knowledge Creep As previously stated, people are naturally curious about instruments and gadgets. When they ask questions about the on-site oil analysis program, the technician educates them about the process and the reason why it is being done. Almost by accident, they learn about the importance of getting the right oil into the right machine, what contamination does to the

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machine, and that the lubricant carries information about machine wear, and so on. They learn about the relationship between proper lubrication and machine reliability. Often for the first time, they become aware that someone is watching. Collectively, this changes behavior, causing them to replace poor lubrication practices with good ones. The gadgets create the interest; the ensuing informal education process produces the change. •

Tangibility On-site testing is tangible and makes oil analysis seem real. As a result, a change occurs in the way that data from an external laboratory are viewed. Because oil analysis takes on a real and tangible persona, the information provided from the laboratory is used in the manner that was intended, increasing its value to the organization. In fact, organizations that use on-site oil analysis usually choose to partner with high-quality external laboratories because they recognize the real importance of laboratory oil analysis for periodic analytical testing and exception-based troubleshooting.

•

Perceived Commitment Lubrication-related activities have never enjoyed great esteem or prestige at most plants. When management commits resources to buy and run equipment for on-site oil analysis, it sends a message that the activity is valued and considered important. This is a fundamental requirement for job satisfaction, passion, and success.

Setting Up Facilities for On-Site Analysis There are numerous ways in which on-site oil analysis can be accomplished with varying degrees of financial commitment. Several companies have product offerings ranging in sophistication from simple, one-dimensional tests to fully equipped mini-labs. Whether the plant is committing to performing a couple of specific tests, or an entire full-capability lab, the requirement for adequate preparation and facilities is necessary. Typically, the space allocated for a test area is often in some dark and unused area of the plant that nobody else wants. Therefore, it is important to plan from the beginning the amount of space required, what furniture and benches are necessary, and to make provisions for storage, lighting, power, and ventilation. In designing the workspace, ergonomics is the key, so that the tests may be conducted quickly, simply, accurately, and safely. Making the work area efficient and the procedures as simple and painless as possible, will encourage ownership and enthusiasm in the program, and will ensure that the job is done properly. Keeping in mind that several people may be involved in the program, procedural consistency and good housekeeping are critical to obtaining accurate, trendable data. By keeping the workspace, neat, tidy, and efficient, both employees and visitors will walk away with the impression that oil analysis is as desirable and critical as any other technology, further enhancing the perceived value of the program.

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Work Area and Health and Safety The work area is critical to the smooth operation of the program. The comfort of the analyst is a prime concern, given the sometimes-tedious nature of the testing. As with any job, giving ownership to the individual responsible will create a strong interest in the program, which may mean that the individual is given an active role in the design of the area. It is also important to ensure that the work area is maintained at a constant room temperature and is adequately ventilated. This will minimize inaccuracies, particularly when conducting tests that are sensitive to temperature fluctuations such as viscosity and water saturation. There should be a workbench at the appropriate height with sufficient work surface in the testing area to allow for instrumentation (typically allow space for double the footprint area of the instrument), and preferably allowing for expansion with further units. Electrical outlets should be provided for the instruments and, in some instances, an air supply line might be required, as well as ventilation where noxious (or flammable) samples or solvent vapors are anticipated. A storage area is also needed for incoming samples. It is recommended that tested samples be held for three months in case of subsequent questions or the need to perform exception testing. Other storage will be required for the portable instruments, consumable materials (such as bottles, and tubing), solvents and reagents, and, if relevant, space for the cart and waste containers. Fluid disposal should be carried out in accordance with local safety and environmental regulations. It is worth requesting a Materials Safety Data Sheet (MSDS) for each lubricant to keep in the office in case questions arise. This serves as a reference for the analyst to check before handling the sample. The MSDS also applies to the chemicals, solvents, or reagents used in some tests, which must be handled and disposed of according to standards. It also goes without saying that smoking should be prohibited in this area. A first-aid kit (with eye-wash solution) and a fire extinguisher should be easily accessible. It is recommended that a small sink unit with hot and cold water be installed, along with providing a good hand soap. In addition to company policy on wearing hard hats and safety shoes when collecting samples, safety gloves and eye protection should be worn at all times. This is especially important when working with on-line test units on high-pressure systems, and when performing tests such as the hot plate crackle test or AN/BN titration. Install a non-slip flooring that is impervious to oil spillage and allows for easy clean up. A concrete floor will look unsightly after a period of time and is difficult to keep clean, which could contribute to airborne contaminant and inaccurate data. For similar reasons, the walls should be painted or tiled to minimize cleaning and dust release. Housekeeping In the interest of good housekeeping, keep paper towels on hand. Place instruments in a stainless steel drip tray to contain any spillage. A special disposal canister should be used for disposal of the paper towel. Paper towels should be high-quality and lint-free to avoid contaminating the samples. 7-6


To avoid creating problems in the future, routine flushing of the instruments after testing should be standard practice by following manufacturers’ guidelines. Build a small recirculating rig to minimize the cost of certain flushing fluids. This is of particular relevance to on-site particle counters. The rig should consist of a tank, a pump, a small 1-micron or 3-micron filter, and a tapping point for dispensing into bottles. For some fluids, an earth strap or grounding line is required to prevent static build-up and the risk of fire. The back flush or drain line from the instruments should be directed to a waste container to avoid contaminating the flushing fluid tank. A supply of environmentally friendly solvents should be kept handy for cleaning the instruments, spillage clean up, or diluting heavy samples. Be sure to wear appropriate surgical safety gloves to avoid skin contact with solvents. When diluting high viscosity samples, dispense the solvent from the canister through a small 0.8µm membrane filter to avoid adding contaminants to the sample. The best canisters for this are stainless steel, which can be pressurized to allow for easy dispensing. Plastic dispensing units tend to shed particles and should be avoided if possible. If extreme levels of fluid cleanliness are measured, then consider using a clean-room cabinet. These have a positive pressure displacement to prevent airborne contaminants from entering the work area, and should be fitted with suitable air filters. Adequate lighting and good ventilation are also important. In all instances where samples are tested for contamination and wear debris, a paint bottle shaker should be used to ensure proper agitation of samples and re-suspension of particles prior to testing. Computers Because many on-site labs are an extension of an existing condition-monitoring program, the data should be used in conjunction with other technologies. As such, it is important to provide a computer to trend the data with other technologies. To facilitate this, network provision is essential to link with other groups and perhaps other sites. Many of the newer instruments now incorporate connectivity via RS232 or similar systems for the upload of data to the computer, so this must be considered when designing the workspace layout. Ideally, a suitable desk should be provided, along with shelving for the storage of files, manuals, and textbooks. Space should be planned for wall charts, which are useful in displaying proper sampling techniques, the shapes of common wear particles, and so on. Lubricant Testing Sorting through the hundreds of different tests that can be performed on petroleum products can be challenging. The goal is to select those tests that should be performed on a regular basis to track and trend the overall lubrication condition. This includes assessing three different areas: wear condition, lubricant properties, and contaminants. Each of these areas is important for monitoring to ensure long life of the machine and the lubricant. An effective oil analysis program provides the testing required to monitor these three areas. It also includes the necessary analysis equipment and techniques that provide the capabilities needed to fulfill the designated test slates for the plant’s machinery. Described here are some of the key tests in each of the three areas used in performing analysis for power plant equipment.

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Wear Condition There are two basic types of wear particle condition analysis, ferrous analysis and elemental analysis. In each case, it is necessary to review the concentrations of debris from the wearing parts of the machine in the lubricated areas, including bearings, gears, journals, oil pump internals, valves, and so on. It is possible to analyze both greases and oils for wear, although the difficulty in obtaining representative and quantitative grease samples has limited its use as a regular diagnostic tool. In oil analysis, the sample is prepared in accordance with the procedures for using the particular wear debris device, as shown in Figure 7-1. Results are reported in quantitative units of ppm or are dimensionless, trendable numbers. By reviewing the wear concentration trends, the equipment can be monitored for changes as an indication of increased wear. Ferrous wear methods are most effective on systems where the primary wear components are steel or iron-based metals.

Figure 7-1 Ferrous Wear Monitors

Both ferrous debris analyses and elemental analyses are used extensively in the power generation industry. However, some early predictive maintenance oil analysis efforts at power plants were based solely on ferrographic analysis, before branching out into the other analysis technologies. Although not all programs include ferrographic analysis, most do include some form of elemental analysis, such as ICP (Figure 7-2, Plasma), or rotating disc spectroscopy (Figure 7-2, Spark). These methods are all limited to the detection of particles less than 10 microns in size, which means that they are not effective at trending the increase of particles characteristic of abnormal wear. Recognition of the particle size limitation of the elemental methods has led some programs to adopt ferrographic analysis, filter patch analysis, particle counting, or rotrode filter spectroscopy.

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Figure 7-2 Elemental Analysis Methods

There are also qualitative methods available to help determine the nature of the wear once it has been identified as being abnormal. These methods include filter patch inspection, analytical ferrography, and optical identification. These techniques separate the solid particles from the oil, and identify the nature of wear by evaluating the shape, size, color, and surface characteristics of the particle. The images in Figure 7-3 show some of the common wear modes and the appearance of the particles they generate. When the quantitative methods (particle counting, ferrous wear debris, etc.) indicate an increasing trend in wear debris, a patch or slide is typically made for microscopic analysis. By determining the nature of the particles in question, wear severity, mode, and possibly the source, can be determined.

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Figure 7-3 Common Wear Modes

At least one recently developed device allows this analysis to take place in the oil stream. LaserNet Fines technology combines laser imaging and artificial intelligence to characterize wear debris in batch oil samples. Its laser-imaging device identifies objects greater than 5 microns and identifies, by wear type, objects that are greater than 20 microns. A neural-net classifier uses object shape and size features to sort particles into various categories such as cutting wear, fatigue wear, sliding wear, and oxides. Particles are then sorted into several bins, including NAS categories of 5–15 microns, 15–25 microns, 25–50 microns, and greater than 50 microns. Lubricant Properties A number of tests are available to monitor the condition of the oil’s physical properties. For the lubricant to continue to provide its intended function, it must maintain certain critical properties, including viscosity, oxidation stability, demulsibility, and foaming characteristics, and the presence of certain additives. Table 7-1 shows a list of the most common lubricant property tests. Not every test needs to be performed on each lubricant, but the decision to perform property testing is dependent on the oil’s intended service conditions and environmental factors. The individual property tests required for given power plant equipment are identified in the Test Slates in Appendix B.

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EPRI Licensed Material Lubricant Analysis Table 7-1 Lubricant Property Tests Viscosity (ASTM D445) at 40ºC and/or 100ºC

Viscosity Index (ASTM D2270) Evaluates viscosity and temperature characteristics of oil

Neutralization (ASTM D974 et al.) Acidity (TAN) and alkalinity (TBN)

Resistivity/Conductivity (ASTM D1169) Evaluates electric current carrying tendency of oil (similar to dielectric property)

Flash Point (ASTM D92) Presence of light oil fractions that vaporize easily

Dielectric Properties Evaluates insulating property of oil as influenced by oxides and other polar molecules

Elemental Analysis (ASTM D5165) Presence of ash-producing inorganic elements, typically additives

Demulsibility (ASTM D1401 and ASTM D2711) Separating efficiency of water from oil

FTIR for Additives Infrared assessment of anti-oxidants and anti-wear additives (molecules)

Foam Tendency (ASTM D892) The tendency of an oil to foam plus stability of foam

Oxidation Stability (ASTM D2272) Stressing conditions determines the remaining oxidative life of oil

Varnish Tendency Various tests that identify abnormal levels of carbon insolubles (for example, fine patch, pentane insolubles, ultracentrifuge, nitration)

FTIR for Oxidation Infrared determines various oxidation components in oil

Color (ASTM D1500) Oil color influenced by oxidative, thermal, and contaminant degradation

Blotter Spot Simple blotter test for dispersancy and oxidation insolubles

One of the most critical property tests, which is performed for every sample, is viscosity. Viscosity is the measure of the primary function of a lubricant to provide separation between moving metal surfaces. Monitoring viscosity also gives indications of changes such as oil oxidation, contamination with products like glycol and diesel fuel, and the addition of oil with the wrong viscosity. Viscosity is measured by absolute or kinematic methods, and is typically reported as kinematic viscosity in centistokes at 40ºC. Figure 7-4 shows the type of tube used to measure kinematic viscosity. Kinematic methods are commonly used in laboratories to measure and report viscosity. In comparison, viscosity measurements in mini-lab kits are typically absolute viscosity devices (Figure 7-5). It is important to distinguish the methods used and to account for specific gravity differences in the used oil before trying to compare results from absolute and kinematic methods.

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Figure 7-4 Device Used to Measure Kinematic Viscosity

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Figure 7-5 Device Used to Measure Absolute Viscosity

Other important property tests include Total Acid Number (TAN) and Total Base Number (TBN) determinations (Figure 7-6). Total Base Number is used to measure the remaining detergency reserve in internal combustion engine crankcase oil. The key role of the detergent additive is to neutralize acidic byproducts of combustion. This basic reserve is typically titrated with hydrochloric acid, and the resulting amount is converted to mg KOH/ml oil to be consistent and comparable to the TAN results. The higher the number, the more basic reserve is present. Therefore, the TBN is an estimate of the remaining life of the oil’s additive package.

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Figure 7-6 Titration

Total Acid Number testing evaluates the increase in total acidic compounds present in the sample over the original amount present in new oil. This is accomplished by preparing the oil and titrating it with a base. The result is expressed in mg KOH/ml oil. As this number increases over the life of the oil, it indicates the accumulation of oxidation byproducts (and possibly other acidic components such as contaminants). When the TAN value is 0.3 greater than the original value of new oil, it is flagged for excessive oxidation and action is taken to correct the situation. A method used to more directly measure the concentration of the anti-oxidation additives present in most of the oils used in the power plant is cyclic voltammetry. The acronym RULER, as mentioned previously, is used to describe the test. By preparing the sample with a reagent based on the oil type, the device measures the concentration of additives such as ZDDP, hindered phenols, and aromatic amines, all used to protect the oil against oxidative stresses. The quantity of the particular additive is compared with the concentration present in new oil, and a trend is indicated for the rate of anti-oxidant depletion. The RULER device is shown in Figure 7-7.

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Figure 7-7 RULER Device

A property test that is rarely performed, but is of particular interest to the power generation industry, is the Rotating Pressure Vessel Oxidation Test (RPVOT). This test performs a simulated aging of the oil by introducing the oxidative stressors of oxygen, water, temperature, catalyst (copper), and agitation. The consumption of oxygen by the vessel, as an indication of the progression of oxidation, is monitored. The result is expressed in minutes of time to reach a certain oxygen pressure drop. The test is used to characterize the oxidation resistance of new turbine oils. It is important for power plants to periodically evaluate the trends in the used oil RPVOT to be aware of the need to address turbine oil condition. If RPVOT trends are caught soon enough, remedial efforts short of complete oil change-out may be possible. Additive level monitoring is also accomplished with elemental analysis, which was discussed earlier. Table 7-2 shows some of the tests used to monitor contaminants and their effectiveness.

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EPRI Licensed Material Lubricant Analysis Table 7-2 Tests Used to Monitor Contaminants Additive

Monitoring Method

Effectiveness

ZDDP (antioxidant, antiwear and corrosion inhibitor)

FTIR – (@ ≈950 wavenumbers) FTIR – oxidation (1750 wn) RPVOT TAN (downward trend) TAN (upward trend) Voltammetry Elemental Spectroscopy

Fair (early detection) Good (later detection) Excellent (early detection) Fair (early detection) Good (later detection) Excellent (early detection) Excellent (early detection)

Rust Inhibitors

Elemental Spectroscopy

Fair (early detection)

Foam Inhibitors


Fair (interferences from dirt)

Sulfur Phosphorus – EP


Excellent

Molybdenum Disulfide – EP


Good

Borate – EP


Excellent

Viscosity Index Improver

Viscosity at 40ºC and 100ºC

Excellent

Dispersants

Blotter Spot Test

Good

Detergents

TBN Elemental Spectroscopy

Excellent Excellent

Hindered Phenol (antioxidant)

FTIR Voltammetry

Fair Excellent (early detection)

Contaminants Contaminants in lubricating oil can be solid, liquid, or gas. Solid contaminants include wear particles (which have already been discussed) and particulates such as dirt. These are typically monitored with particle counters. Particle counters use either light-extinction, laser scatter, or pore-blocking methods. Each instrument is calibrated against a reference fluid and reports the particulate population of the oil sample in given particle-size ranges. These methods don’t actually count particles, but their measurements give a general idea of the cleanliness of the oil sample. This is extremely important in certain systems such as the EHC system and other hydraulic systems that are hypersensitive to particle contamination. In general, turbine oils should also be evaluated with particle counting after outages, at a minimum, to meet manufacturer’s criteria for cleanliness. An aggressive proactive maintenance program that focuses on oil cleanliness to improve equipment life is dependent on routine and accurate particulate counting. Moisture is one of the most damaging contaminants in lube oil. It is a source of oxidation of both the machine metal parts and the oil itself. It can be emulsified with the oil, and can affect the ability of the oil to form its part-separating function even at low levels. It is generally monitored either by using a hotplate or “crackle” test, or by coulometric or potentiometric methods. The Karl Fisher test is the most commonly used laboratory method for determining precise moisture

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levels in oil. The method requires the use of reagents and frequent unit calibration checks. The results are typically expressed in either ppm or percent. Figure 7-8 shows a Karl Fisher titrator.

Figure 7-8 Karl Fischer Titrator

Glycol, diesel fuel, and other process contaminants are typically monitored by Fourier Transform Infrared spectroscopy (FTIR). This device evaluates the absorbance of infrared energy by the oil sample at key frequencies that indicate chemical functional groups. For example, -OH, which represents a single hydrogen and single oxygen atom bonded together, has a characteristic peak in the IR spectrum. Strong absorbance at that frequency could indicate contamination with water, glycol, or other similar products. The FTIR also has the capability to measure oxidation, sulfur and nitrogen products, and even additives. It is one of the most versatile tools in the oil analysis lab, and is frequently used as a catch all screening method to determine when other more complicated tests should be performed. Figure 7-9 shows an FTIR analyzer.

Figure 7-9 FTIR Analyzer

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Mini-Lab Analysis Testing A number of manufacturers offer multi-capable mini-labs for performing on-site analysis. In some cases, these products are integrated with vibration or other software to provide overall predictive maintenance capabilities. These mini-labs can perform analysis of particulate, ferrous wear, moisture, and oxidation. Although they can be a very effective part of an overall oil analysis program, they are not a substitute for the analysis capabilities listed previously. The optimal employment of a mini-lab includes a clear procedure that indicates the proper testing regimen and has direction for follow-up actions to be taken based on the mini-lab results. These follow-up actions should indicate the necessity to increase sampling frequency, to send samples to a full-service lab, and which tests that lab should perform. By using a mini-lab, the plant can have the capability to screen its oil samples before needing to send them off for analysis, and can have early indication of any samples that may be posing a problem. Figures 7-10 and 7-11 show two commonly used mini-labs, and Table 7-3 lists some of the mini-lab and portable equipment suppliers.

Figure 7-10 Entek Mini-Lab

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Figure 7-11 Computational Systems Inc. (CSI) Mini-Lab

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EPRI Licensed Material Lubricant Analysis Table 7-3 List of Some Mini-Lab and Equipment Suppliers Supplier

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Web Site

Description

ARTI

www.artinstruments.com

Particle counter

Cambridge Applied Systems

www.cambridgeapplied.com

Compact electronic viscometer

Computational Systems Inc. (CSI)

www.compsys.com

Fully integrated mini-lab encompassing fluid health, contamination, wear detection/analysis and software

Dexsil Corporation

www.dexsil.com

Acid number (AN) kits, base number (BN), and moisture meter

Entek Division of Rockwell Automation

www.entek.com

Mix and match selection of particle counter, ferrous particle counter, viscometer, percent saturation (moisture meter and software)

Herguth

www.herguth.com

Radial planar chromatography used to separate the components of lubricating oil

Kochler

www.kochlerinstruments.com

Oxidation stability meter that estimates remaining useful life (RUL), acid number equivalent, and base number equivalent. Integrated offering of viscometry and on-site chemical test, including acid number, base number, moisture level, and so on.

Louis C. Eitzen Co.

www.visgage.com

Falling ball comparative viscometer

Pacific Scientific Instruments

www.particle.com

On-line particle counter

Pall Corporation

www.pall.com

Particle counters (optical and pore blockage) and percent saturation meter (moisture)

Predict/DLI

www.predictdli.com

Dielectric screening device reporting abnormal oil health, contamination, and wear debris

OilPro

www.oilpro.com

Portable unit that monitors and trends fluids, contaminants, chemical degradation, and wear

Onboard Technologies Inc.

www.onboardtechnologies.com

Benchtop unit that measures the concentration of soot in engine oil

Schematic Approach

www.schemata.com

Integrated offering of patch test, viscometry, and on-site chemical test, including acid number, base number, moisture level, and so on.

Wilks Enterprise

www.wilksir.com

Compact infrared soot meter


Sensory Tests Not to be overlooked is the importance and impact of including sensory tests during the sampling and analysis processes. The observations of the sampling technician are the first indication of a potential problem. A sample that is cloudy indicates a likely water contamination and should be moved to the front of the queue for analysis. Discoloration or an off-smell can indicate oxidation or contaminants, and the presence of shiny metallic particles is a clear sign of a major problem. In all of these cases, it is important that the sampling technicians have been trained to distinguish generally good used oil from oils that give sensory clues to an abnormal condition. This takes some guidance, as some conditions may be difficult to pick up or distinguish. For example, if a sample is highly agitated when drawn, there may be entrained air that will make the sample appear to have water-induced cloudiness to the untrained eye. The technician would need to know that it is necessary to give the sample some settling time before making an assessment. The amount of time it takes to settle may also give an indication of abnormal condition. These sensory tests should be captured in the procedure for sampling. Expectations should be communicated regarding the sensory tests to be regularly performed and the actions to be taken by the technician when abnormal conditions are noted. Certain indications require immediate action, such as very high water levels or visible metallic debris. Rather than waiting for the detailed analysis from the laboratory, remedial actions or follow-up inspections can be performed to determine if an urgent problem is present. By properly training sampling technicians, a first line of defense can be established for the oil analysis process.

Analysis Frequency One of the most prominent questions in a person’s mind when discussing an oil analysis program design is, “How often should I sample this machine?” Although it may not be the simple answer they are seeking, the correct response is, “How reliable a system do you require?” One simply cannot offer an opinion without understanding a number of factors, such as the age of the oil or the machine, the specific targets for each parameter, the environment and duty, and, more importantly, the value of the machine to the plant and the safety risks associated with failure. Predictive Versus Proactive When selecting sampling frequencies, it is important to consider whether a predictive or proactive strategy is to be used. With a predictive approach, the program is geared toward looking for signs of impending failure. As such, no warning sign is too soon, suggesting that a predictive oil analysis strategy may mean more frequent sampling. With a proactive approach, the key focus should be monitoring root cause parameters, such as contamination or lubricant degradation. In this case, the sampling frequency will depend on the criticality of the unit, the application and environment severity, the age of the lubricant and machine, and the aggressiveness of the goal-based proactive targets. The upside to a proactive strategy is that the occurrence of abnormal conditions will be far less frequent than under a predictive maintenance regime, because the proactive approach essentially equates to healthier machines plant-wide. Although proactive oil analysis usually means higher cost due to the inclusion of more 7-21


sophisticated tests, in the long term it usually reduces overall sampling cost with more time spent solving root cause problems and less time recovering from failures. The first step in setting up an oil analysis program is to select the systems to be monitored, and then establish the sampling frequency. This will dictate the tools and services required to achieve oil analysis success. For example, assume that for a specific machine, safety, process criticality, and economic penalty of failure dictate that sampling should be on-line, and in real-time. These factors suggest the need to procure an on-line instrument. Conversely, if the sample frequency analysis reveals that a three-month interval is appropriate, then a commercial laboratory service may be the answer. In this case, sample frequency influences not only how often an oil sample is taken, but also the entire approach to the oil analysis program design (Figure 7-12).

Figure 7-12 Approach to Oil Analysis Program

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Optimizing with a Sample Frequency Generator The Sample Frequency Generator shown in Figure 7-13 provides a systematic method for estimating the optimized sampling frequency, taking into account the economic penalty of failure, fluid environment severity, machine age, oil age, and the tightness of goal-based targets such as contamination control. These factors are discussed after Figure 7-13. To use the tool, select the best-fit default frequency identified in Step 1 of Figure 7-13. Then, score the application-related factors identified in Step 2. Finally, multiply the best-fit default frequency by the lowest application score to arrive at the adjusted sampling interval. As a caveat, Step 2 should be considered pseudo-quantitative, meaning that one selects a number to represent his or her opinion. Because opinions vary, each machine type should be scored as a group consensus, contributed by the process stakeholders. This approach has proven to be more effective with this type of tool.

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Figure 7-13 Sample Frequency Generator

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Economic Penalty of Failure As expected, the economic penalty of failure adjusts the factor according to the cost of failure; that is, it would double the sampling frequency if it were very low, but would increase it ten fold if it were high. The penalty of failure must take into account the cost of downtime, the cost of repair or rebuild, the overall interruption to business, and the impact on product quality, or output, where applicable. Fluid Environment Severity Fluid environment severity includes more than just the opportunity for particulate, process chemical, and moisture contamination. It also takes into account the demands placed on the lubricant by the machine. This includes the pressure, speed and load, as well as the duty cycle. The greater the risk of lubricant damage, the more frequent the sampling. Machine Age Geriatrics has an impact on establishing sampling frequencies. Sampling frequencies must be modified according to the classic “bathtub” curve used to explain the probability of equipment failure illustrated in Figure 7-14. In general, component failure is most likely during break-in, due to infant mortality, and, of course, as a component reaches the end of its natural life. For this reason, sampling frequencies must be increased during these periods of higher failure probability, particularly when analysis results indicate impending machine mortality.

Figure 7-14 “Bathtub Curve” – Probability of Equipment Failure

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Oil Age This geriatric rule also applies to the lubricant. Aside from the obvious new oil sample for baseline purposes, the lubricant needs a frequent recheck in the first 10% of its expected life to ensure that it is bedding in correctly. This is particularly true when a new oil type or supplier is used. Notice how the adjustment factor is somewhat different between the age of the machine and the age of the oil. A lubricant is more likely to suffer a mid-life crisis than a machine when impacted by accidental ingress conditions and is, thus, less recoverable than a machine at that point. Target Tightness The final consideration is the tightness of any goal-based limits. For example, if a fluid cleanliness target of ISO 15/13/10 is set, and the average fluid cleanliness is normally around ISO 14/12/9, then this is considered tight; if it typically trends at ISO 11/9/6, then this is considered loose. Tight targets require more frequent sampling because the possibility of exceeding the target will occur more readily for them than for targets that are relatively loose. Putting Sampling Intervals to Work One consideration when applying this strategy is to understand that the machine and oil age are moving targets, so readjustment will be required as the machine and oil age. However, if the target tightness, fluid environment severity, or economic penalties scored high and dictated a factor of 0.1, then an adjustment to the age of the machine or oil may not apply because the single lowest factor overrides the adjustment. In the worst-case scenario, an adjustment factor of 0.1 would indicate a daily sampling frequency. In this case, the use of on-line sensors is likely the most cost-effective strategy because the initial cost would soon be recovered in the savings on laboratory expenses, or even the labor costs of performing the analysis on-site. However, an on-line portable unit might also be considered if a number of systems require daily sampling because one unit can be applied to a number of machines. Again, the sampling frequency will have a major influence on oil analysis program design considerations. The frequencies calculated using the Sample Frequency Generator might seem tight compared to historical programs and a paradigm shift in expectations may be necessary. This approach is designed for a proactive strategy, which requires frequent analysis to check for root cause conditions. As a general reference, most power plant programs have adopted oil sampling frequencies that range from monthly to quarterly for most machines. Any increase in sampling frequency may be perceived as merely an increase in workload. It is important to demonstrate that the sampling frequency has been optimized to ensure early detection of latent problems. By being able to identify and correct problems at their earliest stages, and making proactive corrections to design, equipment, and processes, frequent sampling will be easily cost-justified by the avoided failures and reactive maintenance activities.

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Test Slates All too often, an oil analysis program is established by contacting a contract lab, and negotiating a contract price for a particular analysis package. Although it is always important to establish the best value for the program, it is wrong to assume a one-size-fits-all mentality for the selection of analysis tests to be performed. Different types of machines have different lubrication requirements and in-service usage conditions. A sample of diesel engine crankcase oil is going to be markedly different than an EHC fluid. Each different type of machine in the facility should be evaluated and a customized test slate should be developed for each one, thus optimizing the analysis process. Test slates are built for the different types of machines present in the plant. A minimum number of test slates should be employed to cover each unique operating and environmental condition. For a power plant, it is not unusual to employ 5–10 different test slates. As experience is gained with the equipment and plant, test slates should be modified and expanded, or combined and revised, as necessary to reflect an optimal testing protocol. Table 7-4 shows an assortment of typical power plant equipment and the test slates that may be assigned to them. The example test slates referenced in the table are given in Appendix B. Table 7-4 Test Slates Equipment

Test Slate

Main Turbine Reservoir

Reference – 1-B Test Slate Steam Turbine Oil

Gas Turbines

Reference – 2-B Test Slate Gas Turbine

Diesel Engine

Reference – 3-B Test Slate Diesel and Gas Engines

Cooling Water Pump

Reference – 4-B Test Slate Motor and Pump Bearings

Large Falk Gear Box (numerous applications)

Reference – 5-B Test Slate Industrial Gear Oils

Medium Vertical Motor

Reference – 4-B Test Slate Motor and Pump Bearings

EHC System

Reference – 6-B Test Slate EHC Oils

Mechanical Draft Cooling Tower Fan Gearbox


Large Vertical Motors

Reference – 4-B Test Slate Motor and Pump and/or Reference – 7-B Test Slate Babbitt Bearings

Large Horizontal Motors

Reference – 4-B Test Slate Motor and Pump and/or Reference – 7-B Test Slate Babbitt Bearings

Pulverizer Gear Boxes


Feedpump and Turbine Bearings

Reference – 1-B Test Slate Steam Turbine Oil

ID and FD Fans

Reference – 7-B Test Slate Babbitt Bearings

Instrument Air Compressors

Reference – 8-B Test Slate Air and Gas Compressors

Chillers

Reference – 9-B Test Slate Chillers and Refrigeration

Vacuum Pumps

Reference – 10-B Test Slate Vacuum Pumps

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8

LUBRICATION/RELUBRICATION PRACTICES

The lubrication of plant machinery is typically an activity that involves more than one organization at the plant. Many times these activities are poorly coordinated between the organizations and, as a result, the quality of the lubrication and relubrication process is often less than satisfactory. The responsibility for lubrication is typically divided between the maintenance and operations departments. The operations department, in many cases, finds itself responsible for the activities of periodically checking the levels in given oil-lubricated machinery and adding or topping-off a quantity as necessary to achieve the proper lubrication level. In addition to the level checking and topping off activities for oil lubricants, greasing is often an activity that is charged to operators. Greasing is typically a time-based activity that is generated from a database of lubrication tasks based on manufacturer recommendations for periodicity of greasing bearings and other lubricated equipment. Maintenance is left with responsibility for the initial lubrication necessary during installation or overhaul. This includes hand packing of grease and the initial fill of oil reservoirs. Oil changes and flushes are typically maintenance activities as well. In this section, three main areas of lubrication and relubrication will be addressed: first, initial lubrication and/or fill of machinery during maintenance, second, top-off to the proper level for oil-lubricated equipment, and, third, periodic greasing of grease-lubricated bearings and other equipment.

Maintenance Filling of Lubricated Equipment When maintenance is performed on machinery (either when initially installing equipment or during maintenance activities that require the draining of oil from the reservoir), this activity must be carefully performed to ensure that the machines will have the proper amount, type, and condition of lubricant needed when they are first started or put back into service. Maintenance Work Orders should include instructions to maintenance technicians regarding the specific type and quantity of lubricant required to properly perform the reservoir fill maintenance task. Procedures should be in effect, whether they are separately written procedures used for oil filling operations, or step-by-step instructions written within the Work Order. This ensures that the proper steps are taken during a maintenance evolution of oil replacement or initial oil fill. Once the correct lubricant has been designated for the machine, and the proper amount is made available to the technicians on the job, the process by which the oil is to be drained and filled from the reservoir should be part of the step-by-step procedure that is provided. These steps include draining the oil into a container for disposal or into a specially cleaned container for 8-1

EPRI Licensed Material Lubrication/Relubrication Practices

reuse upon the completion of work. In the case where the oil is to be reused, it is mandatory that the oil be run through a filter before being returned to the reservoir. This can be accomplished with some of the commonly used filter fill-rigs, as shown in Figure 8-1. The container receiving the drained oil must be free of any contaminants, liquid or particulate, before it is used for that purpose. It should also be free from any other type of lubricant where a residual amount could cause product cross-contamination.

Figure 8-1 Portable Filtration Rig

When the oil removed from the equipment is to be disposed of, the container used must be clearly labeled as an oil disposal container so that it doesn’t inadvertently get reused as new lubricant. Figure 8-2 shows the proper labeling of containers. After draining the oil from the machine, all openings should be closed to prevent the ingress of dirt and other contaminants during the maintenance activity. When the oil is returned to the machine through a filter, it should be filled to the proper level as designated by the “shutdown level” on a sight-glass or bull’s-eye level indicator.

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Figure 8-2 Labeling of Oil Disposal Container

Level settings for drip- and bottle-type oilers can be particularly challenging when there is a lack of understanding of their proper operation. Wherever the drip-type oilers (shown in Figure 8-3) are being used, the specific instructions for proper set-up, operation, and level setting should be included with the maintenance Work Order for reference. The setting of lubricant levels for dripor bottle-type oilers can be complicated and the procedure must dictate the proper lubrication level at shutdown, against a specific machine reference point. This level can be very critical and a variation of as little as 3/16 of an inch (.48 cm) on either side of the optimal oil level can result in under-filling or over-filling of a small reservoir.

Figure 8-3 Drip-Type and Bottle-Type Oilers

The lack of a vent can cause the level in the reservoir to persist at a higher level than the set point of the drip-oiler. As a result, the entire ball or bottle can empty when set at the intended level, while the remainder of the oil spills out of the reservoir. Care must also be given to the 8-3


positioning of the vent, so that any ambient air currents do not impact the ability of the vent to produce a uniform pressure between the reservoir and either the sight glass, head space, or the area around the oiler-ball drip nozzle. A reference document for the proper setting of the Trico brand of oilers is included in Appendix C. In those machines where the initial oil fill does not deliver oil to all of the lubricated areas within the machine’s circulation path, it may be necessary to check the oil level after the machine has had a short running period. This will ensure that the oil has gone into other clearances and locations, and that the as-left oil level after the maintenance work is complete adequately reflects the intended shutdown oil level for the machine. The initial greasing of new machinery, or machinery in the process of being overhauled, must also be done properly. Hand packing of grease into bearings, couplings, and other greaselubricated equipment should be in accordance with the manufacturer’s recommendations for both method and quantity. Over-greasing or under-greasing these components can result in damage during initial running and premature failure. The use of sealed and shielded bearings should always be reviewed to ensure that the type of shields or seals reflects the type of service, machine, and environmental conditions. Truly sealed bearings cannot be relubricated after installation—they are designed to remain as is for the life of the bearing. Single-shielded bearings can be relubricated, provided that the grease pathway allows for grease entry and purging on the non-shielded side. As far as double-shielded bearings are concerned, there are varying schools of thought on the ability and adequacy of regreasing double-shielded bearings. Although some have made efforts to demonstrate the ability to relubricate double-shielded bearings, it should be noted that bearing manufacturers design double-shielded and sealed bearings to be lubed-for-life. The following are some shield/seal basics that every lube technician should know: •

Bearing shields help bearings retain grease and prevent large particles and contaminants from entering bearing cavities. However, because shields do not make contact with the bearing inner ring, however, they cannot protect bearings from small, finely ground particles, or from liquid contaminants, including water.

•

In high-contaminant applications, many users install sealed bearings. Unlike shields, bearing seals contact the bearing inner ring, preventing the entry of a wide range of contaminants, including liquids and small particles. But this seal-inner ring contact creates friction during operation and can potentially increase bearing operating temperatures. Consequently, sealed bearings are rated for lower speeds than shielded bearings.

•

Both sealed and shielded electric motor bearings are normally considered lubed-for-life. In other words, the life expectancy of these motor bearings is dependent on the life expectancy of their lubrication. Bearings without seals or shields, on the other hand, are usually designed to be relubricated.

The primary question that should be asked when installing double-shielded bearings would be, “Is the double-shielded bearing the correct bearing for the application?” For most power plant bearing applications, single-shielded or non-shielded bearings that can be re-greased through a 8-4


pressurized grease fitting are the proper application and will allow the plant to provide periodic re-greasing of the bearing on a frequency that has been determined to be optimal. Figure 8-4 shows an unshielded/unsealed bearing that includes a pathway for grease replenishment. Where the application specifically calls for sealed or shielded bearings, their condition must be carefully monitored by vibration or ultrasonic analysis, and their replacement should be scheduled when they no longer indicate that they are operating in a low-friction lubricated condition.

Figure 8-4 Unshielded/Unsealed Bearing

Level Checking and Top-Off of Oil Lubricated Equipment For most power plants, operators are given the task of checking oil levels on oil-lubricated machinery as part of their daily or shift rounds. In order to perform this task properly, each sightglass or bull’s-eye level indication should have both a clearly marked shutdown level and an acceptable operating range. Some plants will simply place a hash mark at the proper shutdown level by using a paint pen or scribing a line in the brass sight-glass casing. The problem with these methods is that there is no differentiation between running and shutdown levels, and no indication of the acceptable operating range. Both bull’s-eye level indicators, Figure 8-5, and vertical sight-glasses, Figure 8-6, should clearly be marked with the proper level. Figure 8-6 shows a well-designed placard that indicates the acceptable operating range with a narrow green band on an otherwise red placard. A single white line indicates the proper shutdown level. The brackets are designed to minimize the possibility of sagging of the placard, and it is properly aligned to the visible glass area of the sight-glass. 8-5


Figure 8-5 Bull’s-Eye Level Indicator without Placard

Figure 8-6 Sight-Glass with Information Placard

For operators or others to check levels, the sight-glass and bull’s-eye indicators must be kept clean. When they are dirty, not only do they present a challenge to reading the level, but also they indicate, and perhaps contribute to, unsatisfactory oil condition. Operator rounds should include a check box for “Sight-Glass Cleaning Required” within the rounds activity to document 8-6


and prompt the creation of a corrective maintenance activity. Clean and legible sight glasses and placards are a sign of a quality lubrication program. When an operator finds the level-indicating device outside of the acceptable operating range, the operator then has the responsibility to add the proper amount of lubricant to restore it to an acceptable level. When the method of adding lubricant is simply pouring more oil into a fill opening, this should be done in a manner that allows the level in the reservoir to adequately stabilize in the level-viewing device, so that over-filling does not occur. When the level is above the acceptable range, an investigation is necessary to determine how the level got that high. Reasons include operator error, thermal expansion, and cooler or seal water leakage. Merely draining off high oil levels without investigating can result in overlooking significant problems with the equipment. For equipment where there is an extreme lag time between the adding of lubricant and the response in the level-indicating device, such lag time should be noted in the rounds documentation to caution operators against trying to fill such a reservoir too quickly and overshooting the desired level. For any oil level indication device to be working properly, the reservoir must be properly vented. In the case of a sight-glass, an improperly vented reservoir connected to a vented sight-glass can result in differential pressure levels and, thus, the sight-glass level will not indicate the true level in the reservoir. One other common way in which oil level problems are encountered in power plants is the case of overzealous painting of machinery that has small reservoirs, which are vented by small holes and small plug vents. Painting can cover up these openings and rob the reservoir of its natural vented state. As a result, some of the over-filling and under-filling problems that were previously described can result. When performing oil re-lubrication, the tools by which the lubricant is delivered to the machine must be carefully chosen and thought out to avoid having this part of the lubrication process compromise the integrity of the lubricant. Oil transfer devices, which are intended to take the oil from bulk storage containers (such as a tank, tote, or drum) to the oil reservoir, can have significant potential for the introduction of contaminants, lubricant mixing, and aging of lubricants prior to being introduced to the machine. In a large number of power plants, examples can still be found of the old style blue engineer oilcan being used to transfer oils. Some of the problems with these oilcans are that there is no ventilation protection and the pouring spout is typically unprotected, which can become dirty and ingest contaminants. The constant filling and refilling of these containers allows the accumulation of particulate contaminants in the container, which can later be dumped into the machine. Also, if the containers are not periodically cleaned, the oil in them can age and result in degradation of the lubricants being added to the machines. Other types of oil transfer containers used include old milk jugs, coffee cans, plastic sample containers, and almost any possible container that you can imagine, including old chemical storage containers. The problems with these range from extremely contaminated internals, which would then be delivered to the oil reservoirs, to residual products from the former use of the containers, which in the case of old chemicals can have an obvious detrimental effect. The best

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practices associated with the use of optimal top-off and transfer containers is covered in detail in Section 3, “Storage and Handling.” A best practice for oil top-off is the recording of volumes of oil added to each machine. The monitoring of oil addition volumes will allow the lubrication engineer to determine situations where excessive lubricant is being added, and will possibly point toward unseen or unrecognized leakage locations. The use of electronic rounds to capture and document oil consumption allows the trending of consumption volumes through the use of an electronic database. Identifying leaks results in minimizing the risk of lubrication starvation failures and it reduces safety risks posed by leaking oil.

Greasing Greasing is another activity that, in many cases, falls to operations personnel or, in some cases, to maintenance technicians or a special lubrication team. In any scenario, the identification of the proper lubricant, the volume to be used, and all of the locations on the machine that require greasing, must be part of the route used to periodically add grease to the machinery. Pressurized greased fittings (PGFs) are the most typical hardware set-up used to accomplish periodic regreasing of bearings. There are two general approaches to regreasing activities. The first and most common is a timebased activity where a greasing interval has been established either by experience or by a manufacturer’s recommendation. Although this method is generally adequate, greater acceptance is being given to condition-based greasing. In both cases, it is important to understand the proper way to grease a bearing and how to use a grease gun. In this section, general good greasing practices will be reviewed with respect to the traditional time-based greasing program. Later, the proper practices performed during a condition-based greasing program will be addressed. Greasing on a Time-Based Interval Greasing Tools and Equipment The grease gun is an effective tool for moving grease to a point of application, though it is often taken for granted. The most common types of grease guns include the lever, pistol-grip, hand grip, air-powered, and battery-powered. The lever style is the most economic and widely used of all the grease guns. The grease gun types used in a given plant should be standardized so that the pump stroke volume delivery amount is uniform, allowing greasing tasks to specify a set number of pumps to achieve proper lubrication volume. Grease guns vary in the amount of grease pumped per stroke, from one to three grams of grease or higher. The actual output can also vary, depending on the age of the grease gun. Lubrication technicians need to know the output per stroke of the grease gun in order to know how much grease is added each time a piece of equipment is lubricated. The volume should be expressed in grams or ounces per pump for the lever-style guns shown in Figure 8-7. Air-powered grease guns (Figure 8-8), or battery-powered units, are typically used only in high-volume applications and the volume should be determined per second, per audible tick made by the unit, or by some other metering device. 8-8


Figure 8-7 Lever-Style Grease Gun

Figure 8-8 Air-Powered Grease Gun

Grease guns should be dedicated to particular greases and they should not be interchanged. It is preferential to use grease tubes as opposed to bulk pails because of the risk of introducing contaminants from bulk pails. Although the overall cost of buying grease in tubes may be higher, potential downside risks from equipment damage caused by contaminants introduced during filling of the grease guns from the large pails will more than offset any cost savings. Another factor to consider is the type of grease fittings used in the facility. Most fittings have a ball check in the head of the fitting, which prevents dirt from getting to the bearing. The spherical contour of the fitting head provides a ball-and-socket joint between the fitting and the hydraulic coupler of the grease gun. The most common fitting is the hydraulic fitting, which is available in both standard and metric sizes. Hydraulic fittings are available in threaded, thread forming, rivet, and drive styles. They are available in different angled configurations and in a wide variety of extension lengths to allow positioning of the fitting for easy access with a grease gun on different types of equipment.

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Grease gun fittings and accessories can enhance a lubrication program in several ways. Colored labels can be used to identify the proper grease to use on a fitting. It is important to ensure that the proper grease is used on the facility’s equipment. Best practices in the power industry include color/shape-coded labeling of grease guns and fittings, with laminated covers to protect the labels and the use of clear gun tubes so that the internal product can be seen. Figure 8-9 shows examples of grease guns with clear tubes. This allows the tube that is inserted to be read directly through the transparent housing. Then there can be little doubt regarding the type of grease being used in that gun. At the machine lubrication points, grease addition points should be clearly labeled on the machine with the type of lubricant to be added and identification of the point name. Color-coding and shape matching systems can further enhance the ability of lubrication technicians to use the right lubricant in the right location.

Figure 8-9 Grease Guns with Clear Tubes

A best practice for greasing is to leave a small amount of grease on the PGF after completion of the greasing task as a protective cover to contaminants. Then, in subsequent greasing, the technician can carefully use a disposable wipe to wipe the old grease dollop up and away from the pressurized grease fitting, carrying with it any dirt that may have accumulated on the grease surface since the last greasing job. This is the most effective way to eliminate the accumulation of dust on the PGF grease fitting itself, which could then be pumped directly into the bearing cavity on subsequent greasing activities. A basic step that is often overlooked is training the lubrication technician in the proper use of the grease gun. A high-pressure grease gun delivers pressure up to 15,000 psi (103 MPa). Most bearing seals will rarely handle more than 500 psi (3.45 MPa). A grease gun in the hands of an untrained technician can compromise the bearing’s seal and lead to early failure. The compromised seal invites dirt or other foreign materials, as well as over-lubrication due to little or no backpressure. When time-interval greasing is used, it is critical that the amount of grease necessary to properly lubricate the bearing is specified clearly in the Work Order or lubrication 8-10


task. This amount or quantity must be translated into a value that the greasing technician can easily comprehend. If all of the grease guns have been standardized, it is possible to arrive at a full-stroke pump volume, and to translate the required grease volume into a total number of fullstroked pumps for the technician. Safety training can also be a factor when using a needlepoint applicator to disperse grease to certain types of fittings. If the needle slips off the grease point and punctures the hand or finger, grease can be forced into the skin. This can cause the punctured area to become swollen, stiff, and even gangrenous, which could lead to amputation. This is why grease gun injuries require immediate medical treatment. Remember to use extreme caution when using needlepoint applicators on grease guns. Some common tips for using a grease gun are: •

Calculate the proper amount of grease needed for re-lubrication of bearings, based upon the calibrated delivery volume of the selected grease gun.

•

Use a vent plug, as shown in Figure 8-10, on the relief port of the bearing to help flush old grease and to reduce the risk of too much pressure on the bearing.

Figure 8-10 Vent Plugs and Relief Fittings

•

Use extreme caution when loading grease into the grease gun to ensure that contaminants are not introduced. If using a cartridge, be careful when removing the metal lid so that no metal slivers are introduced into the grease.

•

Make sure that the grease gun is clearly marked to identify the grease with which it should be charged. Do not use any type of grease other than that which is identified.

•

Always make sure the dispensing nozzle of the grease gun is clean before using, as demonstrated in Figure 8-11. Pump a small amount of grease out of the dispensing nozzle and then wipe it off with a clean rag or lint-free cloth before attaching to the grease fitting.

8-11


Figure 8-11 Cleaned Grease Gun Nozzle

•

Clean the grease fitting of all dirt before attaching the grease gun. Inspect and replace damaged fittings. Also clean the grease fitting after applying grease. It is helpful to use grease-fitting caps to keep them clean, but still wipe fittings clean before applying grease.

•

Ensure that the proper grease is used at every grease point. Applying the wrong grease can cause an incompatibility problem that can quickly cause bearing failure. Lubrication points should be clearly identified regarding which grease is to be used. This can be done with colored labels, adhesive dots, or paint markers.

•

Grease guns should be stored unpressurized in a clean, cool, dry area and in a horizontal position to help keep the oil from bleeding out of the grease. Grease gun clamps make storage easy and organized. Also cover the coupler to keep it free from dirt and contaminants.

•

Calibrate grease guns regularly to ensure the proper delivery volume.

•

Use caution and safety when working around moving equipment and when using a grease gun.

Avoiding Over-Greasing Over-greasing rolling element bearings in motors has been an industry problem for many years. More motors have bearing failures due to over-greasing than from under-greasing. For the nuclear power generation industry in particular, the U.S. Nuclear Regulatory Commission (NRC) provided guidance and direction through the development of Information Notice 88-012, issued in July 1988. In this notice, the NRC lists the following guidelines to correct or prevent motor over-greasing and related problems: •

Review motor lubrication procedures to ensure that they identify the type and quantity of grease to use, the specific fill and drain nozzles to uncap, and the length of time that motors should run with drain plugs off after greasing the bearings.

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•

To prevent foreign materials from contaminating the grease, ensure that grease containers are covered during periods of storage, and ensure that nozzles and grease fittings are cleaned.

•

Determine the optimum quantity and correct type of grease required for each motor by examining the manufacturer’s recommendations and by monitoring the behavior of the grease added to motors.

This method delivered mixed performance results for the amount of resources that companies have had to devote to motor relubrication, motivating some organizations to develop additional improvements. One such improvement, developed through a coordinated effort between EPRI and several utilities, is the Electric Motor Predictive and Preventive Maintenance Guide (NP-7502), which provides guidance on how to regrease motors, when to add grease, and how much grease to add. However, although NP-7502 is a useful guideline, it cannot be applied to resolve the issue of over-greasing motors that are already in service, and already have an unknown quantity of grease in the bearing cavity. Consequently, even with the NP-7502 guidance, over-lubrication of greased bearings could still be a problem. The normal sequence when regreasing motor bearings is as follows: 1. If possible, the bearing should be at a stable, normal operating temperature, making the grease less viscous. 2. Remove the drain plug and any hardened grease. 3. Clean the grease (zerk) fitting before attaching the grease gun. 4. Use the regreasing guidance provided by EPRI NP-7502 for the grease fill quantity and regreasing frequency. 5. After regreasing is complete, leave the drain port open and operate the motor under normal bearing operating temperatures for at least one hour. This allows the grease to thermally expand and vent out of the port, relieving any excess pressure in the cavity. 6. After thermal expansion is complete, clean the excess grease and reinstall the drain plug. This sequence requires several hours with operational support to grease and operate each motor. With the large number of motors that require lubrication in a power plant, there is considerable cost associated with motor lubrication. Additionally, even when the sequence is followed precisely, a bearing cavity may still become overfilled throughout the life of the bearing. This is further complicated if the existing quantity of grease in the grease cavity for a motor is unknown. To eliminate over-greasing and to reduce the maintenance and operational support time needed to perform regreasing, existing relief ports and hydraulic fill fittings can be replaced with relief valves and pressure-controlled grease-fill fittings. This new method incorporates the new fittings as follows: 1. Install a pressure-sensitive (20 psi [138 kPa] differential) grease-fill fitting that will not allow the cavity to be pressurized beyond 20 psi (138 kPa). This should minimize excessive pressure buildup on the bearing shield while the motor is being regreased.

8-13


2. Install a grease-relief valve fitting to take the place of the grease drain plug. The grease-relief valve will open between 1 psi and 5 psi (6.89 kPa and 34.5 kPa) and will minimize the risk of over-pressurization of the grease cavity from relubrication and thermal expansion of the grease (while running the motor). 3. Follow the regreasing guidance given in Appendix B of EPRI Report NP-7502, Electric Motor Predictive and Preventive Maintenance Guide. Some plants have, in an effort to improve the greasing process, installed extension tubes from a remote PGF location to the greased bearing. In some cases, this is done to address safety concerns or parts that would otherwise be difficult to grease because of the location of the greased part. The problem with using grease extension tubes is two-fold. Because the extension tubing is not completely rigid, the pressure generated by the grease gun is not directly transmitted to the bearing. There will be some difference in the manner in which the grease is added to the bearing. There will be compression, possible leakage, and other problems with the pumped grease. As a result, final pressure at the end of the extension tube may not meet the intended pressure of grease delivery for proper lubrication. The second problem is in the delay from the time of greasing to the time at which that portion actually makes it to the machine. In an extremely long run, the grease will remain in the extension tube for many greasing intervals as it slowly works its way forward to the bearing. The elapsed time that grease remains in an extension tube until it finally gets to the lubricated part can be years. Wherever possible, greasing extension tubes should be eliminated in favor of grease guns with long discharge tubes. When grease extension tubes are absolutely necessary, their lengths should be minimized and their construction should be of heavy-duty piping that would minimize the potential for tube breakage, leakage, and pressure losses. Greasing technicians should have, as part of their toolbox, a number of disposable wipes to be used to clean off both the tip of the grease gun and the grease pressure fittings. The grease guns should either be fitted with rigid tubes or flexible hoses in accordance with the location and configuration of the fittings on the machines. It may be necessary to have more than one type of grease gun available to a technician to optimize the greasing function for all of the types and situations of grease fittings that will be encountered. Additionally, grease extension tubes, although not recommended for the machines, can be useful when added to the grease gun itself to reach difficult or distant locations. Condition-Based Greasing Condition-based greasing involves the use of ultrasonic technology to listen to the bearings, prior to and during the greasing process, to ensure that the optimal amount of grease is added to the bearing when it is needed. Figure 8-12 shows various ultrasonic condition-based greasing devices. In this scenario, a time interval is set for a technician with an ultrasonic listening device, either independent of or integral to the grease gun, to place the device on the bearing or grease fitting to check for indication of inadequate lubrication in the ultrasonic signal response. If the bearing shows no indication of inadequate greasing, grease is not added to that bearing, or only a minimal amount is added. When a less than adequate lubrication signature is provided by the ultrasound test, then an amount of grease is added to restore that bearing to the properly 8-14


lubricated condition. This approach to greasing will generally eliminate many of the problems associated with over-greasing of bearings, which is one of the most common failure mechanisms for greased-bearing equipment.

Figure 8-12 Ultrasonic Condition-Based Greasing Devices

Multiple frequency sonic/ultrasonic analysis can be effectively used to monitor the lubrication quality of greased bearings. As a proactive tool, ultrasonic lubrication monitoring can eliminate under/over-greasing, which are common root causes of failure, before costly damage occurs. Likewise, ultrasonic monitoring can detect a bad acting bearing in the early stages of failure to facilitate the scheduling of corrective actions. Although practical from a testing point of view, applying traditional oil analysis to greaselubricated bearings is often impractical due to the difficulty in obtaining a representative sample of grease to analyze. Considering the significant number of grease-lubricated machines in a typical power plant, the challenge of ensuring proper lubrication is a serious one that needs to be addressed. Used routinely, ultrasonic analysis can play an important role in ensuring the proper lubrication of greased bearings. Proactive by nature, the technique effectively identifies when lubrication is required. Properly applied, it proves an effective defense against over- or under-lubrication. It also enables those hard-to-reach bearings to be greased on-condition only, avoiding unnecessary cost and risk or discomfort to the lubrication technician. The stated goal for condition-based greasing is to detect the early signs of inadequate lubrication and to take corrective action before the onset of bearing damage. It should be noted that, unlike vibration analysis, the target frequency is not a function of the machine’s running speed (rpm). Responding to the damage caused by over-greasing, under-greasing, wrong grease, and sometimes no grease is among the most significant challenges faced by maintenance technicians. The trick is to detect the signs of lubricant starvation with enough advance warning to take corrective action before damage occurs to the components. Doing so enables the technician to take preemptive measures before the reliability of the machine is compromised. 8-15


9

PROGRAM MANAGEMENT

Large amounts of maintenance dollars and resources are often budgeted to develop and implement an initiative such as a lubrication program. Once the program is in place, however, attention focused on ensuring that full benefit is continually received from the initial expenditure may be insufficient. Programs put in place to meet a requirement or management expectations, without established ownership and a guiding vision, can decay into a low value day-to-day chore. The maintenance tasks supporting the program may eventually be looked at as busy work and, as a result, may even be deferred. To defend against this possible loss of program focus and value, a program document and dedicated program ownership must be clearly established as part of the development and implementation process. Without ownership, the organizational changes that have become a part of every day life in power plants can undermine the intent and benefits of a well-developed lubrication program. Although all power generation facilities have a lubrication function, not all recognize it as a total program. Even in facilities where there are no efforts to perform oil analysis, or any of the other proactive measures that are mentioned throughout this document, there are still activities related to lubrication, including purchasing, filling of equipment, topping-off, changing oil, disposal, and so on. The lubrication function typically falls under a number of different organizations such as Operations, Maintenance, Procurement, Engineering, Storeroom, Chemistry, or other departments. When the components of the lubrication function are performed over such a wide range of organizations and individual responsibilities, it can be difficult to establish a cohesive effort to pursue lubrication excellence. That is why one of the key elements, program management, is so critical in ensuring progress toward the goal of achieving lubrication excellence. Program management begins with an understanding of all of the key elements needed to establish a quality lubrication program. There also needs to be an understanding of the roles and responsibilities that must be in place to ensure that the completion of various activities associated with such a program are performed by the many different disciplines. Some of these activities include: •

Product receipt and inspection

•

Equipment overhauls/PM activities

•

Quality assurance

•


•

Engineering design

•

Equipment sampling

•

Analysis and reporting 9-1

EPRI Licensed Material Program Management

•

Equipment top-off

•

Sample tap installation

•

Lubrication tasks

•

Equipment walk-downs

•

Disposal

One of the first steps in pulling this effort together is the creation of a program document, or procedure, that governs the scope and defines the roles and responsibilities of those individuals whose activities impact the lubrication program. This document must be a living product so that it reflects changes in the program and captures experiences and best practices.

Dedicated Ownership of the Lubrication Program Although a program document lays the groundwork for creating and defining the program, the establishment of a program owner is the single most important step in ensuring development, growth, and focus as the plant’s work practices begin to change. Program ownership may come in several different forms. During program development and implementation, a team of employees will join to provide the necessary input to ensure that the program development process meets the needs and expectations of the management sponsor. The group usually includes, but is not limited to, representatives from plant Operations, Engineering, Maintenance, Work Management, and PdM personnel. Input from the lubricant vendor and laboratory service providers may also be beneficial. To provide a single point of focus for this concerted effort, it is important that a single individual in the organization be appointed as the overall Program Owner. This individual should be knowledgeable in a number of areas. The Program Owner should have the following: •

A full understanding of why each task type (routine task, PM, PdM) was selected for each component in the lubrication program

•

A working knowledge of the plant’s corrective maintenance (CM), preventive maintenance (PM), predictive maintenance (PdM), and proactive maintenance (PAM) processes

•

Strong training and background in lubrication theory, application, and laboratory analysis

•

An entrepreneurial mindset without fear of change

•

A working knowledge of the components in the program

•

The ability to communicate with others responsible for equipment reliability

Communication will be key as the Program Owner works with various plant personnel to establish specific roles and responsibilities required to implement and sustain a quality lubrication program.

9-2


Roles and Responsibilities When implementing a comprehensive lubrication program, it is extremely important to identify all tasks that are required to establish and sustain an effective program. It is equally important to establish clear expectations and to assign roles and responsibilities for these tasks. One main reason for this is the fact that the various individuals assigned to perform the lubrication-related functions stated previously, typically do not report to the Program Owner. This may create problems if priorities and expectations are not the same. The information obtained as a result of the tasks being performed will be instrumental in ensuring the overall maintenance and reliability of the plant’s critical equipment. It is recommended that, when establishing roles and responsibilities, the lubrication Program Owner meet with the Management Team to discuss the expectations associated with each work group’s roles and responsibilities. Sometimes this may mean the establishment of interface agreements that define how each work group will act. An example of the fruits of an effort such as this comes from a plant that had severe contamination problems, where particle counts on much of the equipment being monitored were extremely high. In many cases, the particle counts could not be obtained due to the high concentrations of water in the oil. Initially, the Program Owner, working in the PdM department under Engineering, tried to address the contamination issue with little success. When investigating the problem, it was found that much of the contamination was the result of poor lubrication handling and equipment top-off practices. Unfortunately, these activities resided in the Operation’s side of the house and had been part of the plant culture for many years. In a case such as this, it is difficult to change the culture or alter personnel behavior through the individual effort of the Program Owner. The solution to this problem came only after realization by the Program Owner that, if the culture was going to change, Operations personnel must be part of that change. They must understand the problems with the existing culture, take at least partial ownership, and must have buy-in to making changes. To this end, the Program Owner met with the Operations Manager and several Operations personnel to discuss the issues. During this meeting, various reasons became apparent as to why the culture was the way that it was. Suggestions were also offered as to how improvements could be made. In the end, the Operations Manager solicited a “champion” within the Operations department to take ownership of the lubrication storage and top-off areas. The Operations champion was to work closely with the Lubrication Program Owner to ensure that the contamination issues were addressed. Basic lubrication training for Operations personnel was scheduled as a result of the meeting. In the end, over a period of time, the serious contamination issue was resolved through teamwork, and everyone involved celebrated the success that was achieved. The previous example demonstrates one way in which a Program Owner should function. The Owner realized the importance of not only identifying problem areas, but of facilitating the process to seek solutions that involved the roles and responsibilities of other workgroups. As stated earlier, communication is key to an effective lubrication program.

9-3


Communication Other types of communication will also be required of the Program Owner as part of program management. Much of this communication will be in the form of verbal communication that may be a phone call, an email, or a personal contact. Participation in meetings, such as reliability and/or planning meetings, may also be required. The Program Owner is ultimately responsible for notifying all personnel or work groups of any conditions that may raise concerns relative to lubricant conditions or equipment health. This communication will often be in the form of formal reports delivered to different levels of management. To determine what information should be in the various reports, it is recommended that the Program Owner visit with the different levels of management, or other pertinent plant personnel who will receive the report, to discuss their expectations and desired report content. When using an electronic means of reporting, this should be a consideration as the reporting function of the software is reviewed or developed. Communication with other program owners within the industry can also be beneficial. A lubrication program owner may have acquired skills through training and field experience; however, not all program owners have acquired the same degree of knowledge in every area. This can be used to an advantage. Sharing of experiences and discoveries with program owners from other plants or utilities is a win-win situation for all willing to share ideas. In other words, it is necessary to: •

Get into the flow of information

•

Request subscriptions to newsletters and journals

•

Attend training and vendor presentations to discover new techniques in sampling and lubricant analysis

•

Discuss the possible use of new products with the plant lubricant vendor

As a Program Owner, networking with others in the industry is essential to maintaining and managing a successful lubrication program.

Quantifying the Benefits of a Lubrication Program Another aspect of good program management is identifying and reporting the value of the lubrication program. This is particularly important as budgets are scrutinized and cuts are made. The application of oil analysis and other precision maintenance activities produces real benefit to the organization. Often, oil analysts think only in terms of the savings associated with extended or condition-based oil changes. They frequently fail to capture value contributions related to equipment reliability or risk reduction. Effective management of lubrication builds reliability into the system, and oil analysis produces tremendous value when it provides advance warning of a failure event. The early warning system allows management to schedule activities to avoid production interruptions, and to have parts and labor lined up. Likewise, oil analysis provides information about the event itself so that the right “fix” is implemented, preferably removing the root cause of the problem. Performing a cost-benefit analysis on significant lubrication events is essential to demonstrating the value of an effective lubrication program. 9-4


Proactive and Predictive Benefits Financial benefits generated by oil analysis and lubrication management come in two forms, proactive benefits and predictive benefits. Proactive activities, such as reducing particle and moisture contamination, changing or reclaiming oil, and upgrading a lubricant’s quality specification actively extend the life of components. By controlling the forcing function, or root cause that leads to a failure, one can preemptively reduce the failure rate for a component or system. For example, the relationship between particle or moisture contamination level and mechanical integrity has been widely researched. Reducing the particle contamination level of the oil lubricating a rolling element bearing from ISO 19/16 to ISO 15/12 will, on average, double the life of the bearing. Likewise, reducing the moisture contamination level in the same rolling element bearing system from 1000 ppm to 250 ppm would double the life of the bearings in the same system. If one elects to control both moisture and particles simultaneously, an additive effect is said to exist, which means that the total life extension is the sum of the parts, as shown in Table 9-1. Quantifying the proactive benefits is obtained with a simple calculation, by dividing the current failure costs due to wear and failure by the life extension factor. In other words, in the bearing system example, every dollar currently lost per year due to failure would be reduced by 75% if the proposed particle and moisture targets were achieved. Proactive maintenance makes money because it effectively reduces the number of failure events that occur in a given time period. Table 9-1 Total Life Extension Parameter

Current Level

Proposed Level

Life Extension

Particle Contamination

ISO 19/16

ISO 15/12

2 Times

Moisture Contamination

1000 ppm

250 ppm

2 Times

Cumulative Life Extension

4 Times

There is inherent complexity in the valuation of PdM activities. The objective for predictive maintenance is to produce a non-event, or to reduce the relative impact or severity of a failure event. Quantifying this can prove to be difficult. The value of PdM lies in its ability to provide advance warning so that unscheduled outages are avoided, parts and labor can be scheduled, runtime compensatory actions can be taken to limp the machine along until the scheduled outage, and costly chain-reaction failures can be avoided. The benefit calculation itself is only an estimate, even if much care is taken to extract details in which the problem was identified and eventually resolved. The difficulty with this estimating process is that critics of PdM will question the validity of the assumptions made to calculate the benefits. When calculating benefits, it is necessary to make assumptions because the actual event, the catastrophic failure of a machine, has not yet occurred. In calculating benefits, there are two areas that immediately come to mind as obvious areas for potential benefits: avoided loss of production and avoided the maintenance cost of parts and labor associated with a more severe failure. Calculating the benefits in these two areas is generally a straightforward process.

9-5


EPRI, through the EPRI Monitoring and Diagnostics Center, has devised a process by which benefits are estimated based upon realistic assumptions and probabilities derived from many years of experience. This procedure is used extensively in the electrical utility industry. Some of the basic assumptions are given in this section; however, the entire procedure is referenced in, “Beyond Detection—Realizing Value in a PdM Program,” George VanDerHorn, Computational Systems, Inc., Proceedings from the Reliability Week Conference, Nashville, TN (1997). Basic Assumptions With any cost benefit analysis procedure, as with the EPRI process, some assumptions and suppositions are needed to simplify the process. Some of the basic assumptions of this procedure are: •

There are two areas where a predictive (condition-based) analysis of plant equipment has an impact on plant operations and maintenance. The first area deals with the loss of generating revenue associated with the detected fault. The second area deals with the maintenance savings associated with early detection of the fault.

•

Not all equipment failures are catastrophic.

•

Not all catastrophic failures result in a loss of production.

•

There are three possible outcomes for any detected plant equipment fault:

•

–

Catastrophic Failure – includes the total destruction of the equipment under surveillance and any other damage caused by the failure. These types of failures are often given a relatively low probability of occurring.

–

Moderate Failure – includes only the cost of replacing the failed component parts and the impact of the failure on generating capability. These types of failures are given a higher probability of occurrence than the catastrophic occurrence.

–

Loss of Performance – includes the costs associated with the resulting loss of service of the faulty equipment if the fault had gone undetected. This category could also be considered a minor failure and it often mirrors the actual cost of the repair.

There are costs associated with the actions taken as a result of an occurrence. These costs are not always known when the cost-benefit analysis is done, so they must be estimated. These costs are subtracted from the estimated total benefit to yield a net benefit differential. The benefits associated with the detection of the fault, as defined in this procedure, are actually this benefit differential. Therefore, the reported benefit is the actual net savings experienced by the utility, not the gross costs avoided.

The M&D Center strongly advises the use of only management-approved cost-benefit procedures. Plant management should be consulted prior to the use of any cost-benefit analysis procedure. If management should disagree with the procedures, then the method should not be used and management should provide an alternative method.

9-6


Program Management Summary Good program management is based on an understanding of the fundamental key elements required to implement and sustain a comprehensive lubrication program as outlined in Section 1. In addition, the program owner must also understand how each element is intricately woven into the others. With this understanding, the program owner must facilitate the process of obtaining lubrication excellence by ensuring that roles and responsibilities are well defined and executed, and that the information obtained from the process is communicated to the appropriate plant personnel to make timely decisions regarding the operation and maintenance of the plant’s critical equipment.

9-7


10

PROCEDURES

Lubrication Procedures Despite requirements for many maintenance and operating activities, and overwhelming evidence suggesting that poor machinery lubrication spells trouble for the plant, most plants lack clearly defined written procedures for performing basic lubrication tasks. The following outlines the importance of procedures for lubrication and four elements of a good lubrication procedure. Importance of Lubrication Procedures •

Work Scope – Procedures clearly scope the work that an individual is expected to perform. They ensure that work is done the way management or engineering requires. If the proper method is to deliver 12 shots of grease pumped into the bearing, allowing 15 seconds to elapse between shots, this requirement can be clearly documented in the procedures.

•

Consistency – In the absence of procedures, five technicians are apt to perform the same task five different ways. In the absence of a procedure, each individual has the freedom to personalize the task at hand. Inconsistency produces undesirable results. Documented procedures bring uniformity into the lubrication task, while keeping everyone on the same page.

•

Best Practices – A procedure creates the framework for standardizing best practices. It serves as the container in which to pour the experience and expertise of employees, outside consultants, vendors, and others into a single document. This convergence process also enables the team to align the procedure to the goals of the organization. Just enough best practice for one machine may be too much for another, depending upon the relative importance of the two machines to plant operations. This can be true even if the two machines are identical in design.

•

Training – Arguably, the most important role of lubrication procedures is that they form the basis for training lube technicians. Basic training about lubrication, lubricants, oil analysis, etc., is designed to provide the foundation that enables individuals to think like lube technicians. Certification is another important part of the training process because it confirms that the individual possesses the skills to perform the job functions. This is called technology training. Although it is important, technology training fails to convey specific task-based instructions for completing a lubrication-related Work Order. A set of procedures serves as a natural curriculum for task-based training. It also serves as the basis for evaluating an individual’s ability to carry out the assigned tasks. Combining basic technology training and third-party certification with task-level training and skill-verification creates a powerful combination and a valuable employee. 10-1

EPRI Licensed Material Procedures

Elements of an Effective Lubrication Procedure •

Emphasize Best Practice – As previously mentioned, procedures enable the incorporation of best practice. However, this is not automatic. A concerted effort must be made to build best practice into the procedure. Access the experience and knowledge of the plant’s own maintenance team, and bring in outside support as required, to ensure that your procedures are up to date and aligned with the business goals.

•

Communicate Clearly – Use clear, easy-to-understand language when creating procedures. Also, use digital photographs to reduce the procedure’s dependence upon words. For intricate tasks, a digital video is an excellent way to communicate tasks that are difficult to describe with words. Good procedures include a top-view of the plant, along with easy-to-spot landmarks that reveal the locations of the machines. Getting to the right machine is the first step. Also, use sketches or photos to identify the physical location of the lube point. Lube points are occasionally missed because their locations are unknown to the technician. Identify required tools and materials for completing the job, to improve work planning, and for assembling a tool kit. Also, don’t forget to identify general safety practices and any specific hazards associated with performing a particular lubrication task.

•

Electronic – Get your lubrication procedures in an electronic form, preferably on the company-wide intranet, or onto an Internet account for those moving toward web-based application support. When the procedures are electronic, they can be updated globally, attached to Work Orders, and linked to like machines in a CMMS system. Digital photographs and video images can easily be attached to a document. Documenting procedures electronically makes sense. It is more efficient and effective than the old paper and three-ring binder method.

•

Continuous Improvement – There is a downside to procedures. Without management support, they can anchor the organization to the past, inhibiting the inclusion of new technology and best practices. Be sure that the program includes a periodic review and improvement process to update and upgrade lubrication procedures. Keeping procedures in an electronic form simplifies continuous improvement because updates don’t require tedious activities to physically replace pages in the lubrication manual. Changes can be documented and communicated in one memorandum, while updating the procedures themselves requires only the touch of a button.

Procedure Topics There are a number of important areas that should be covered by procedures when considering the entire lubrication program. They include: •

Cleaning and reconditioning containers

•

Flushing systems after overhaul or repair

•

Conducting an oil change

•

Lubricant sampling procedures

•

Lubricating machines

10-2


Cleaning and Reconditioning Containers Transfer containers used to take lubricants from the bulk storage location to the machine will inevitably become dirty over time. A procedure should be in place to define how the containers are monitored for cleanliness and cross-contamination from improper filling. When a container has been identified as needing reconditioning, the procedure should specify how this is to be accomplished, and it should be specific to the type of container used at the facility. Consulting with the supplier of the transfer container can be helpful in developing the proper steps to clean the container. Typically, flushing with a low viscosity compatible oil is a good method. Heating the oil to lower its viscosity, or using a pump and wand with nozzle, will generate a high velocity jet that helps to loosen particles and sticky fluid. When a container cannot be easily and confidently cleaned, it must be discarded and replaced. Refillable tanks and totes should also be included in the container reconditioning procedure. Due to a lack of a valid procedure for cleaning turbine oil storage tanks, some power plants have actually seen particulate levels rise after performing a tank “cleaning.” Without the knowledge of the impact of very small particles, it is sometimes mistakenly assumed that “looks clean” equals cleanliness. To avoid the possibility of resuspending settled contaminants, leaving rag fibers behind, and otherwise performing an ineffective tank cleaning, a clear procedure should be written to prescribe the proper practices. This would include the use of recirculation pumps and filters, using heating and high velocity to put particulates into suspension, and ensuring that all corners and cavities are thoroughly flushed. Flushing Systems After Overhaul or Repair Turbine flushes are a normal and expected part of power plant turbine maintenance. In many cases, there are requirements to do so whenever there is any kind of invasive maintenance or repair. Because of the pressure to reduce outage times, some utilities have challenged the need to perform flushes, sometimes with significant consequences. Certainly, some consideration must be given to the possibility of skipping a full turbine flush if the type of maintenance performed is rather minor and extreme care is taken to exclude contaminants. This is where a procedure to provide guidance in this decision process can be helpful. Defining those activities that require a turbine flush, and also those proactive measures to be taken to minimize contaminant intrusion during maintenance, should be included. A more effective strategy to minimize the impact of turbine flushes is to make the flush condition-based. Historically, the turbine flush was conducted by making all of the necessary piping changes, installing the flushing skid, and performing the flush for a pre-determined time period, perhaps as long as 2 or 3 days. There are two problems with this approach: the first is the assumption that the oil is indeed at the necessary cleanliness levels without confirmatory testing. The second problem is that, in many cases, the turbine flush is being run far longer than necessary. A better approach is to use an on-line particle counter in conjunction with the flush. By monitoring the bulk tank condition, it is possible to achieve the acceptable cleanliness criteria, or perhaps a tighter proactive cleanliness target. In this way, the duration of the flush can be optimized by flushing no longer than what is required to meet preset levels. 10-3


Although turbines are certainly one of the most critical plant machines, they are not the only expensive and important lubricated machinery. Oil flushes should be similarly proceduralized for other critical equipment like circulation water pumps, condensate pumps, feedwater pumps, and pulverizers. Flushing equipment need not be elaborate but must be able to generated sufficient velocity in the reservoir to put the particulate and contaminants into suspension, and include a filtration system to remove them. Conducting an Oil Change Oil changes, in order to be effective, are not to be performed the same way on every machine. Consideration must be given to known conditions about the reservoir being changed, the viscosity and other properties of the oil, and certain environmental factors. If a reservoir has a relatively open and circular geometry, a simple drain, flush, and fill may be adequate. If there are significant traps and tight clearances, a more thorough flush may be necessary. Some equipment cannot simply be drained and filled, but must include a post-fill circulating filtration during operation to ensure that all retained contaminants are flushed out. By identifying the particular needs for each machine, and specifying the needed equipment and proper practices, oil changes can achieve their desired results. Lubricant Sampling Procedures Sampling techniques have been given in Section 4. The wide variety of optimal methods and hardware to obtain representative samples brings with it the need to define the proper sampling procedures. For the plant, there should be a defined number of different sampling scenarios, and each machine should be identified by the sampling scenario that applies. In the sampling scheduling activity, reference should be made to the proper sampling procedure and the needed supplies and equipment. Lubricating Machines The job of lubricating machines sometimes falls across organizational boundaries at the plant. Many different hands may be involved in performing initial fills, checking levels, and toppingoff. It is not always obvious what the proper lubricant level should be, how and under what conditions it can be checked, and how to adjust the level as needed. Experience sometimes shows particular practices that must be captured to ensure that machines are not over- or underlubricated. Procedures should be in place for checking levels, greasing, adding oil during maintenance activities, and adding oil during operation. The use of filter-fill rigs, extension tubes, and other machine-specific needs are to be included in the procedures to ensure consistent practices.

Procedure Considerations A lubrication procedure guides the user through a specific lubrication task. There are many types of tasks, such as manual bearing lubrication, gearbox filling, gearbox checking, gearbox top-off, 10-4


gearbox cleaning, kidney loop filtration, sample collection, and so on. Each of these tasks will have some degree of uniqueness, as well as a great deal of overlap with other similar lubrication tasks. When preparing a lubrication procedure, consider the following: •

Strategy – How does the procedure support the broader maintenance strategy?

•

Purpose – What needs to be accomplished?

•

Procedure – How is the task accomplished, including the many details that determine safety, efficiency, and effectiveness?

Strategy The lubrication program should not be an isolated island in the sea of maintenance practices. Lubrication practices should align concisely with the defined, supported goals of the larger maintenance operation. With increasing demand for equipment availability, most plants have instituted a Reliability-Centered Maintenance (RCM) process. Through this process, they’ve identified where and how to devote their energies to maintain their equipment. Within this strategy, decisions have been made to determine which machines can run-to-failure. Other machines, perhaps similar, must be maintained to ensure maximum availability. To maximize a limited lubrication resource, the lubrication procedures for a particular machine should fit the broader strategy for that machine. For example, a gearbox on a conveyor may be designated runto-failure with an anticipated five-year life span, although an identical gearbox on a similar conveyor may be designated as process-critical, with the difference between the two units being the material conveyed. Depending on the number of run-to-failure units on hand, it may be best to develop a procedure to select a lifecycle fill strategy (lubed for life) that incorporates the use of a high-performance lubricant in a sealed application, with no planned routine service. Conversely, although the reliability expectation is higher for the other unit, consider using a product that does not offer the extended lifecycle benefits if the intention is to closely monitor the unit for signs of distress. Stepping into the procedure development process, there is a need to confirm that the practice for each system aligns well with the stated maintenance goal for that system. The optimization of maintenance activities will lead to greater lubrication efficiency and effectiveness at a reduced total cost. Purpose Keeping this strategy in mind, the purpose is to state what is to be accomplished for the lubrication procedure. Although there is no single approach to defining the purpose and the individual tasks for the procedure, certain specifics must be included to remove ambiguity and ensure compliance. The purpose should include, at a minimum: •

The name of the item to be addressed (example: 3AP003 Condensate Pump)

•

The objective of the work (semi-annual coupling inspection and relubrication) 10-5


•

Identification of the individual to perform the task, including certification requirements from the training and certification matrix (Lubrication Technician, MLT Level I, or STLE OMA-1 Certified)

•

Operational and safety conditions (for example, equipment must be locked out before work can be accomplished)

•

The amount of time allocated to the task

The details should identify what is to be done, where it is to be done, who will do the work, tools and materials needed, special issues surrounding the work (safety, operational) and how much time is allotted to the task. In the process of devising and writing procedures, expect to find major similarities between like components grouped by maintenance strategy. A template can be created with a significant amount of generic information or structure to facilitate the process without diluting the results. Procedure While keeping the strategy in mind, the procedure needs to support five principles, or tenets, historically referred to as the five Rs of lubrication, which are: •

The Right product

•

The Right place

•

The Right amount

•

The Right time

•

The Right attitude

Digging for details is a must for the first four Rs. Sometimes the details are within easy grasp. Sometimes guidelines are developed as progress is made and when the team has a better understanding of what is needed. More likely than not, if the development of world-class procedures is the objective, they have to be developed in-house, perhaps with the aid of a corporate or external consultant or specialist. The following are discussions regarding each of the five categories (the five Rs) and questions that should be asked. Right Product This pertains to the selection of the lubricant for an application. The original equipment manufacturer (OEM) should be the starting point for product selection, by viscosity grade and boundary film formation properties (AW, EP, solids), for both oil and grease products. The OEM has probably considered the speed and load required of the operating equipment components and has calculated a minimum viscosity for that condition. However, because the OEM will not understand the specific operating conditions, factor in actual conditions and modify the OEM baseline recommendation to fit accordingly.

10-6


For instance, is the gearbox rated for one speed but operated at another speed? Is the gearbox in an elevated ambient temperature location, or is there significant process temperature transferred throughout the shaft to the gear case? Is there risk of manufacturing or process contamination entering the lubrication compartment before or during installation? Is the unit accessible? Does the unit have a heat control mechanism (heat exchanger, fan)? What lubricant products are readily available to help meet the OEM’s existing mechanical and environmental conditions? Can the company accept a specialty lube product for this single application? The answers to each of these questions must have a bearing on the lube product that is finally selected. One point of interest: decisions must be based on the in-plant equipment, the best lubricants available, and the maintenance strategy. Decisions must also be made that fit budgets and goals. Collect input from various resources (such as the local distributor, OEM, lubricant manufacturer, or subject matter expert) but use internal resources—the company team—to make the final educated decisions. Right Place This decision is predetermined by the plant and the equipment design process for the vast majority of applications. Nonetheless, confirm that the details are correct. OEM guidelines are just that, guidelines. Every single lubrication application point must be uncovered, photographed, tagged, and reinforced. This requires having people at the equipment and looking at the drive train or process flow. A cross-functional work team is key to running down all of these details. The operators live with the equipment on a day-to-day basis and they generally understand what is missed and what is not. Right Amount Assessing oil volume requirements is generally straightforward. For instance, calculate the amount of oil that goes into an isolated, splash-lubricated, wet sump gear case. The level does not change much between standby and operating modes. Circulating oil systems present a greater degree of difficulty because lubrication lines contain oil outside of the reservoir. For circulating systems, factor in the volume of lubricant in transit, and estimate an operating level as well as a standby level. Once the reservoir is filled, the task is to maintain the right predefined level. Grease lubrication is more challenging. Manual grease relubrication is probably the single most out-of-control aspect of machinery lubrication, but it doesn’t have to be that way. The right amount can be calculated easily with a few measurements and quick formulas or charts from bearing suppliers. After calculating the component requirement from the design criteria, add an environmental factor based on the actual installation, the lubricant properties, and the time available for relubrication. Many factors interrelate to influence the volume and cycle. They must be considered in the context of producing a whole picture. Be sure that the grease guns in use are standardized on a per-pump delivery volume, and determine the quantity per pump. Instructions to lubrication technicians should use the “number of pumps” when specifying the volume needed for lubrication tasks. 10-7


Right Time The timing of re-lubrication intervals is influenced by many of the same factors that influence relubrication quantities. Start with the OEM guideline and adjust it to maximize the properties of the lubricant within the context of the application and environment. The environment will have a significant impact on grease relubrication intervals, but less so on oil-lubricated equipment. The most difficult part of this procedure is identifying the operating and design details. Right Attitude Regardless of the level of efficiency and accuracy in defining the physical properties and requirements for optimum lubrication, the human element is the trump card. Well-defined but poorly followed practices are of marginal value. Likewise, highly motivated people without role definition will either find a way to define their role or will lose interest. The right attitude boils down to a personal decision made by the lubrication technician, but it is greatly influenced by senior management’s attitude toward the role.

10-8


11

PROGRAM GOALS AND METRICS

The establishment of meaningful goals and metrics are key to implementing or improving a lubrication program. The selection of specific program goals, and the development of key performance indicators by which to measure the progress toward meeting those goals, are largely dependent on the maturity of the lubrication program. Unfortunately, the development of goals and metrics continues to be an area of weakness in many of the programs. Although most organizations have established corporate- and plant-specific goals and metrics aimed at overall operating and maintenance improvements, few programs have established goals and metrics at the technology level. This key program element is required to ensure lubrication program excellence. It is also important to have a clear understanding of the current status of the program, and it is equally important to have vision and focus on the continued improvements that can be made to the program to realize effective and efficient fulfillment of the lubrication needs of the organization.

Establishment of Specific Program Goals and Metrics As previously stated, the development of goals and metrics for the lubrication program will differ depending on the plant’s existing lubrication program. Although the same approach may be taken to determine specific goals and metrics, in most cases the maturity of the program will determine the priority of initial goals and the criteria that will be applied. In either case, it is important to have a clear understanding of the current status of the lubrication program. This is typically accomplished by performing an audit of current efforts. In the case of a new program, the primary goal will be the identification of overall program needs and the development of roles and responsibilities. The development of an implementation plan and schedule will also help to ensure that the effort moves forward as schedule compliance is measured. Initial focus will be on putting the program structure in place and in making sure that specific tasks are completed so that the program can move forward. Some of these tasks or goals often include the following: •

Assign lubrication Program Owner

•

Resolve roles and responsibilities with appropriate workgroups

•

Identify sample tap locations for all equipment to be monitored

•

Purchase and install sampling taps

•

Establish machine-specific test slates

•

Identify and develop appropriate procedures and guidelines

•

Identify training requirements for all personnel involved in the lubrication program

•

Address all action items resulting from the audit report 11-1

EPRI Licensed Material Program Goals and Metrics

A more mature program will typically focus on raising the bar of previously created goals, such as refining alert and alarm limits, determining root causes of lubricant-related equipment failures, extending or eliminating lubrication PM tasks, and reducing oil consumption by initiating additional proactive measures. It is the intent of the authors of this guideline to encourage the reader or lubrication program owner to be proactive and consider ways in which to achieve lubrication excellence through the process of establishing goals and metrics for their program. The following examples are some of the goals and metrics that have been implemented for existing programs by better performing organizations. Reduce Lubricant Costs The expenditures necessary to establish the total amount of dollars spent on lubricants in a given time period may not be readily available. However, a review of storeroom records and purchasing contracts can usually be performed to establish this value without too much effort. An annual expenditure on lubricants would also be a good place to start to get an overall feel for the consumption rate for the facility. In a lubrication optimization program, the goal is to minimize the purchase of new lubricants through the consolidation of products, the elimination of time-based oil changes, and minimizing of waste and leakage. When properly done, all of these measures should have a measurable effect on the dollars being spent per year on lubricants. Improve the Percent Compliance to Scheduled Lubrication PM Tasks Many lubrication tasks are scheduled activities related to performing inspections, sampling for oil analysis, regreasing, top-ups, and scheduled oil changes (where condition-based oil changes aren’t feasible). Several common problems exist with respect to the completion of scheduled PMs. Supervisors often pull designated technicians away from lube PMs to help with repair work, or to perform a number of other tasks within the plant. Lubrication audits have discovered that, in some plants, lube technicians are called away from lubrication tasks 50% of the time or more. As a result, these PMs either pile up or get canceled, and they are not done until the next time they come up on the schedule. Measuring the percent conformance to PM completion targets is fairly simple. If the PM is scheduled, and it is completed, that task is in conformance. If it is not completed for whatever reason, the task is non-conforming. The percent that the total PMs were completed should be reported. Adjust or Redefine Analysis Alert or Alarm Limits Once initial alert and alarm limits have been defined as part of the data analysis process, analysis data must be reviewed to ensure that the original target values are correct and that they appropriately reflect the true condition of the equipment components. This is often accomplished by incorporating feedback from the maintenance activities and using lessons learned resulting from root cause analyses of failed components. Additional information regarding this process can be found in Section 13. 11-2


Improve Equipment Reliability Performance indicators (PIs) relating to equipment reliability are typically included as part of the PdM program PIs. But lubrication-related issues affecting the reliability of equipment should also be tracked as part of the overall metrics of the lubrication program. The goal is to minimize or reduce the number of lubrication-related equipment failures or significant events. This is sometimes difficult to determine because the actual root cause of the problem may not always be correctly identified. Improve Oil Cleanliness Levels It has been stated that improving the cleanliness levels of the lubricant has a direct effect on component life. An example of this was given in Section 9, which stated that reducing the particle contamination level of the oil lubricating a rolling element bearing from ISO 19/16 to ISO 15/12 will, on average, double the life of the bearing. With this in mind, the setting and achievement of target cleanliness levels have proven to be a worthwhile goal for many organizations. Figure 11-1 shows what a Key Performance Indicator (KPI) display for tracking cleanliness targets might look like.

Figure 11-1 Cleanliness Goals KPI Display

Lubricant Disposal Costs By tracking and trending lubricant disposal costs, it is possible to not only get an idea of the total consumption, leaks, and oil changes, but it also presents a measure by which behaviors can be influenced. Recognition of the true costs of disposal can also be a significant driver toward reduction of time-based oil changes in favor of condition-based filtration or reclamation. Where it exists as an option, burning lube oil in on-site boilers can be a near zero-cost activity. Reconditioning of used oil by advanced filtration techniques, ion-exchange for phosphate esters, and readditization for lightly oxidized oil, can all have significant impact on this important economic metric. 11-3


In summary, the examples given in this section for establishing goals and metrics are provided to stimulate the thoughts of the reader or Program Owner. Each organization, therefore, must determine the status of their lubrication program and establish site-specific goals and metrics for their respective program. Once selected, the goals and metrics should be prominently displayed and tracked where everyone involved can see them. As goals are achieved, recognition should be given where appropriate and this success should be celebrated. As stated previously, this area remains a weakness of many lubrication programs. It is the intent of the EPRI team to document and capture additional goals and metrics for inclusion in a future revision to this guideline.

11-4


12

SAFETY PRACTICES

There are few modern industrial endeavors that do not include some measure of safety awareness, both in the way in which the facility is laid out, and in the guarding of personnel from material and hazards. In power generation, safety always plays some role in ongoing operations. The type of facility may influence the amount of attention given to safety issues. For instance, nuclear power has a high built-in level of safety expectations that is a product of the necessary attention to detail that goes into the operation of a nuclear power plant. It is typical to find a general safety culture in place, in varying degrees of rigor, in most all types of power generation facilities. When it comes to lubrication safety, there are a number of unique aspects regarding the use and handling of lubricants. By their very nature, lubricants are slippery. It is their design to minimize friction in the machine. But when this property is imparted outside of the machine to floors, handrails, stair steps, and other undesirable locations, it can lead to a high-risk situation that must be immediately attended to in order to prevent personnel injury. Lubricants, because they are usually hydrocarbon derivatives, are flammable and the proper firehazard precautions should be taken. Finally, some lubricants may cause personnel health problems on contact.

Storage Attention to safety needs to start when the lubricants arrive on site. It has already been mentioned as part of the procurement process that receipt inspection must include an evaluation of the lubricant containers to ensure that there is no spillage. In addition to this being a quality control issue, it is also a safety issue. Any product that spills from its vessel must immediately be contained. For greases, this is less of a problem but, for oils, liquid containment measures must be readily available and adequate to prevent any impact on personnel, equipment, or the environment. Portable berms (Figure 12-1), storm grate covers, and absorbent pads and pigs need to be available in the area where lubricants are handled when they first arrive at the plant. The potential for the puncturing of drums with forklift tines, dropped containers bursting open, and the initial discovery of delivered leaky containers makes this a high-risk area for lubricant leakage. The delivery off-loading area should typically include a liquid containment berm to prevent any of the liquids escaping and making the clean-up process more difficult. Damaged or suspect containers should be immediately returned to the supplier without taking receipt of the shipment. There is great difficulty in trying to properly salvage lubricants from a damaged container and it is much easier to put the onus for proper container condition on the supplier at the time of delivery. 12-1

EPRI Licensed Material Safety Practices

Figure 12-1 Portable Berms

Personnel who are on-site and charged with the handling of lubricants, including the receipt and movement of the delivered lubricants from the shipper, should be trained in the hazards posed by lubricant products and the proper personal protection measures that should be taken. Figure 12-2 illustrates such a precautionary notice.

Figure 12-2 Area Lubricant Notification Sign

Material Safety Data Sheets (MSDSs) should be readily available in those locations where lubricants are handled, as shown in Figure 12-3. The proper personnel protective equipment (PPE) should also be readily accessible to these personnel. 12-2


Figure 12-3 MSDS Properly Located

Although most lubricants in their end-user form are generally not considered to be flammable substances, nearly all are categorized as combustibles. Certain precautions, therefore, should be made when handling combustibles, including fire prevention measures in areas where they will be gathered together and stored in significant quantities. This would include storeroom storage areas, temporary storage shelters, and storage and dispensing locations throughout the plant. In each of these areas, sprinkler systems or other fire suppression measures should be in place to reduce the risk of the potential consequences of combustion of lubricants. Fire extinguishers should also be available in these areas and should be of a type appropriate for fighting flammable liquid fires. Whenever satellite locations are used to store lubricants, whether they are drums and totes throughout the plant, or even transfer containers staged in specific locations that make relubrication more convenient, appropriate fire protection measures must be in place. These might include the use of fireproof cabinets to store transfer containers, grease guns, and small lubricant containers, the use of berms to contain spillage, or the availability of temporary fire protection measures in staging areas.

Handling Different types of lubricants pose different risks. A commonly used lubricant in generation applications is the phosphate ester used commonly in EHC fluids. This phosphate ester typically presents significant corrosion and carcinogenic risks to those involved with handling it. Therefore, a leaky drum of phosphate ester poses a risk to the uneducated handler who might otherwise assume that “oil is oil.” Without specific instruction in the hazards posed by industrial lubricants, people may assume that there is little risk in handling lubricants. Experience working with common household lubricants, such as general-purpose products like WD40 and the handling of motor oils for vehicle maintenance, may give a general impression that little 12-3


protection is necessary. However, the industrial formulations used in power plants pose separate risks. Care should be taken to make sure that all personnel that come in contact with these products have been properly trained and prepared to deal with the safety risks. All safety precautions that are dictated by the MSDS for the various lubricant products used in the plant should be followed. These might include such measures as having an eyewash and shower station in close proximity to certain lubricant products that pose an eye or skin irritation risk. Easily portable and maintainable eyewash and shower stations can be set up in areas near where lubricants are being stored or dispensed. Spill-response kits should also be set up wherever there is a location for the storage and/or dispensing of lubricants. These spill-response kits (Figure 12-4) should include pigs to contain and absorb spills, absorbent blanket pads, rags, and portable berms or drain covers to prevent or to allow containment of any significant spills.

Figure 12-4 Spill-Response Kit

In and Around Machines There needs to be a low threshold of tolerance for lubricant leakage and spills in the plant. Large amounts of lubricant leakage that are not properly contained pose the most common risk of personnel injury due to slips and falls from oily surfaces. Machines that are chronic oil leakers should have appropriate measures in place to contain any lubricant leakage by the use of pigs, berms, and absorbent blankets, until such time that the proper maintenance can be scheduled and performed to eliminate the root cause of the lubricant leakage. All leaks should be confined, so that they do not result in the coating of personnel-traveled areas such as walkways, catwalks, ladders, and other accessible areas. Areas where oil mist is routinely generated should have specific warning signs and placards posted to notify personnel in the vicinity to use extreme caution when accessing this equipment. Machines that mist or leak routinely should be identified and their leakage amount quantified, 12-4


where possible, so that severity and priority for corrective actions to eliminate the sources of potentially dangerous lubricant spillages can be assigned. General site-safety procedures and training curricula should be reviewed to focus on the areas where specific attention may be neglected for lubrication and lubricant safety issues. Initial personnel safety training should include awareness of the risks of handling lubricants, including skin contact, eye contact, inhalation, ingestion, carcinogenic risk, and also the physical risks due to slips, trips, and falls precipitated by slippery surfaces generated by lubricant leakage. Management expectations for minimizing lubricant leaks should clearly be communicated and should be reflected by the priority that is given to the repair of leaking machinery. MSDSs must be obtained and made readily available to personnel involved in handling lubricants, including storeroom storage areas, disposal areas, in-plant storage and dispensing stations, satellite locations, oil sampling equipment storage, and around specific machines where large quantities of oil are used, such as the main turbines. Lubrication activities that involve working in close proximity to operating and rotating machinery include relubrication (greasing and oil level top-offs), oil sampling, and oil level checks. Personnel should be made aware of the risks inherent in lubrication activities, the procedural safety steps, and the training process. This includes an attention to detail when in the proximity of exposed rotating shafts. The added risk that spilled oil, grease, or oil mist will accumulate in the area of oil reservoirs, increases the likelihood of these surfaces being slippery and the possibility of someone slipping or falling into the operating machine.

Sampling The action of taking oil samples puts the person at risk of coming in physical contact with the lubricants and, in some cases, in a fairly hot state. Where lubricant operating temperatures exceed 140°F (60°C), there should be a special warning to those involved in the oil sampling procedure to take precautions to avoid burns from hot oil when it comes out of the machine. A properly obtained oil sample will include the purging of any dead leg sections. These sections will initially be much cooler than the temperature of the oil in the live zone of the reservoir. Therefore, personnel should be prepared and should take precaution against the fact that the oil temperature will rise as the oil is being purged and the representative sample volume begins to emerge from the machine. Ultimately, this temperature will approach the internal bulk lubricant temperature for the reservoir. When that value is above 140°F (60°C), direct contact should be avoided. Special efforts such as insulated rubber gloves may be necessary to ensure safe handling. Care should be taken to wipe down all surfaces in the vicinity where the oil sampling is done. However, care must also be taken with the material used for that wipe down because there is a risk of the material being drawn into the rotating shaft or motor vent intakes. Care must be taken in the handling of plastic tubing used to draw samples. Any plastic tubing fed into an oil reservoir must be done so in a manner that precludes the possibility that the tubing could either get wrapped around a rotating shaft or drawn into the teeth of meshing gears, for instance.

12-5


Disposal When the job is complete, and the oil has finished its useful life, there may be a temptation to reduce the vigilance with which lubricants are handled. However, in some cases, the disposal phase of the life of the lubricant may be one of the most risky to individuals and the environment. The containers used to hold oils being readied for disposal are sometimes the oldest, most beat-up containers around. The thought may be that, because the oil is being thrown out, the quality of the disposal container is not a concern. The risk of leakage is certainly increased with the use of substandard disposal containers, and should be avoided. Efforts should be made to limit access to these containers. They are often too tempting a target receptacle, with their inviting funnel on top, and they end up being the final resting place for other hazardous chemicals. These mixtures can be very dangerous, particularly if the handling and disposal manner assumes a mixture of used lubricants only. Figure 12-5 demonstrates incorrect lubricant container conditions.

Figure 12-5 Incorrect Lubricant Disposal

In addition to the disposal of the liquid oils, proper disposal of the greases and wiping materials should be provided for as well. A clearly marked receptacle should be made available in areas convenient to the disposal of those items. Thought should also be given to the accumulation of combustible materials in the disposal of greases and oily/greasy rags. Figure 12-6 shows a typical clearly marked container.

12-6


Figure 12-6 Clearly Marked Receptacle

The safe handling of lubricants and safe work practices around lubricated machinery are an important part of a successful lubrication program. Personnel injuries are unacceptable and avoidable with careful planning, education, and precautions. The “cradle-to-grave” approach must apply to the safety culture to ensure that lubrication activities are performed safely and efficiently.

12-7


13

CONTINUOUS IMPROVEMENT

Continuous improvement is an important element of a comprehensive lubrication program, but one that is often overlooked by many. It has been stated that, in order to get better, it is necessary to understand where you are. By using the audit process described in Section 1, an organization will have a roadmap to address and evaluate where they presently stand and what needs to be their focus. It must also be understood that continuous improvement is a living program, continually changing to ensure both equipment reliability and ultimate cost effectiveness. Both technical and programmatic issues need to be addressed. Although all of the elements of a comprehensive lubrication program mentioned previously should be reviewed when evaluating areas for improvement, the following are some examples and guidelines to be considered.

Procedures and Guidelines A plant lubrication program is only as good as the procedures guiding the process and the individuals performing lubrication activities. The continuous improvement philosophy allows the plant to control changes and make adjustments to the lubrication program content by using historical data and adapting to new methods, techniques, and industry standards. By empowering employees to learn about and incorporate new technologies and methodologies, program quiescence can be avoided. By using procedures to document changes and standardize lubrication activities, program drift (which can diminish lubrication gains over time if focus on lubrication excellence is lost) can be eliminated. An effort, therefore, must be made to continually revise and update the lubrication program procedures and guidelines.

Oil Sampling and Analysis Careful consideration must be given to the sample point location and analysis results to ensure that the information obtained is valid. This information is used to evaluate component health and any instance of unrepresentative samples or inaccurate analyses can result in an inaccurate diagnosis. A periodic review of sampling locations may identify opportunities to use more representative locations, or to use improved sampling hardware, to increase the quality of sampling. A periodic audit of sampling actions, and comparing field practices to best practices defined in this guideline, may reveal a drift in the quality of the process. This is particularly important as personnel changes are experienced or time constraints of the sampling technicians increase and challenge their ability to complete assigned sampling tasks in the proper manner and prescribed method. After implementing a sampling and analysis process as part of a comprehensive lubrication program, analysis data must be reviewed and baselines should be established. From the 13-1

EPRI Licensed Material Continuous Improvement

baselines, alert and alarm limits should be established, with target values that indicate component health. This information can then be used to trigger proactive maintenance activities. The initial limits and target values are determined by current standards and best practices, experience in the industry, and possible input from other company plants. As part of the continuous improvement process, these targets and limits should be revised and improved by incorporating feedback from maintenance activities. Additionally, lessons learned from root cause analysis of failed components should be used. This information can help refine the trigger points and improve the overall effectiveness of the program. For instance, if it is found that there is a set action level for bearing replacement based on bestpractices, and that the bearings being removed when those levels are reached still have significant remaining life (as indicated by post-maintenance metallurgical evaluation), consideration should be given to increasing those values to extend the wear life of the bearings. Conversely, if there are an unacceptable number of bearing failures, a review of the oil analysis data of those failed components should be performed to see if, in hindsight, a failure trend was observable. If so, it may be necessary to tighten the alarm and alert levels to ensure that preemptive measures are taken prior to failure.

Work Closeout As stated in the previous paragraph, one of the best ways to improve the overall effectiveness of the lubrication program is to learn from the maintenance activities by evaluating the as-found condition of the components. Review of this information can give significant insight into the effectiveness of the lube oil technology application, or the need to change or revise lubricationrelated tasks. This is sometimes difficult to evaluate, as work closeout information may not always be readily available. Additional information may be obtained as a result of the root cause analysis performed on a failed component. Even when this information does exist, it is often not available to those involved in the lubrication program. In the continuous improvement process, barriers should be identified and removed to ensure continued program growth.

Culture Change One of the most difficult things to do when implementing a comprehensive lubrication program is to change the way in which an organization thinks. This is particularly true when dealing with storage and handling, contamination, and lubrication practices. As stated in Section 6 (Training), personnel must be trained so that they can properly perform their tasks. They must also understand their roles and responsibilities and understand the value of what they are being asked to do. Although initial training will satisfy these needs, a continuous effort must be asserted in each area until the culture is changed. An example previously given of a culture requiring change was the statement “oil is oil.” Another mindset found in many organizations in need of a culture change is, “we have always done it this way.” Continuous improvement must be exercised in all areas of the lubrication program until the culture has changed. This is often accomplished through the use of follow-on training, management support, recognition, and celebration of program successes.

13-2


Customer Satisfaction To improve the lubrication program, it is important to have an understanding of the services that the lubrication program provides, and to have an awareness of who the customers are for each of these services. In most cases, the customers include maintenance, operations, engineering, and any other work groups that may have a need for lubrication information. Typically, the lubrication program owner, as defined in Section 9 (“Program Management”), is a service provider to these workgroups. These services include the oversight of lubrication procedures, storage and handling issues, oil sampling and data analysis, procurement issues, and overall lubrication program management. In essence, the lubrication program owner is the “go to” person at the site for all lubrication-related issues. Although several of these activities may reside in various departments, the program owner is expected to be cognizant of these activities and ensure that they are integrated into the overall lubrication program effort. As part of the continuous improvement effort, it is important that the customer be solicited for feedback regarding program performance and customer satisfaction. There is no better method to obtain feedback than interviewing the customer. At a minimum, this should be an annual activity performed to determine if customer needs are being met. Typical questions should focus on reporting expectations, early warning of impending failures, and potential reduction or extension of lubrication-related tasks. There is also opportunity during these interviews to increase communication and capture recommendations for program improvement.

Adopting Continuous Improvement Behaviors The continuous improvement of a lubrication program is a never-ending road to success. However, it is important to slow down periodically and determine if the process is headed in the right direction. The lubrication program owner must participate with industry groups, review proven best practices, and attend lubrication conferences, while continually adapting the knowledge gained to specific plant needs. Other related activities, such as attending classes, subscribing to industry publications, and communicating new techniques to laboratory personnel are also beneficial. For organizations with multiple sites, the opportunity to share experiences and information can provide significant benefit, particularly when those sites are of similar design. The ability to share data to identify analysis trends, appropriate alert and alarm limits, and warnings of lubricant-related failure experiences provide significant benefits. Even when there is not an overlap in plant design similarity, culture issues can be common. The lessons learned by the lubrication program manager at one facility may be of great value and interest to others in the organization when they involve standard practices, cultural shortcomings, or internally generated best practices. Periodic meetings of key lubrication personnel should be part of the improvement strategy to facilitate this exchange of information.

Failure Modes Effects Analysis (FMEA) The FMEA process must also be considered as a continuous improvement effort. Unlike failure root cause analysis (FRCA), which is used to analyze failures after the fact, FMEA is a systematic process used to identify potential failure modes and effects before failures occur. In reality, FRCA and FMEA work hand-in-hand. FRCA sets the stage for the FMEA, which, in 13-3


turn, produces a plan to deploy appropriate maintenance actions. FRCA alone is limited because failure occurs before it can be applied, proving too costly for critical systems. It is more practical to estimate likely failure modes and sequences in advance, or to simulate failures in an experimental situation, rather than allowing a failure to occur before a maintenance plan has been instated. In about 70% of the cases where mechanical equipment loses usefulness, wear out or corrosion is the cause of surface degradation. Industry experts generally agree that between 40% and 75% of all wear in industrial equipment is in some way related to lubrication, making it responsible for between 25% and 50% of lost usefulness of industrial equipment. Despite the prevalence of lubrication-related failures, the manner in which they are typically documented at the plant is quite casual. For example, sudden volumetric loss of the lubricant caused by a drain plug vibrating loose, and the addition of the wrong lubricant into the system, might be generally categorized as a lubrication failure. Although both can significantly impair lubrication, the mechanisms by which equipment reaches the failed state are not comparable. It should also be noted that lubrication failures are often misdiagnosed as bearing failures, pump failures, etc., which are symptoms, not causes. When lubrication is correctly identified as the cause of failure, the nature of the lubrication failure is not clear enough to be useful. FMEA is an excellent inductive analysis tool that adds precision to identifying lubrication failures, and it enables asset managers to anticipate and plan for them with cost-effective maintenance strategies. The FMEA Process The different components and steps of the basic maintenance FMEA process are illustrated in Figure 13-1, and they are described in the tasks that follow.

Figure 13-1 FMEA Process

13-4


Establishing the FMEA process includes the following tasks: 1. List the equipment at the system and/or sub-system level. The degree to which one wishes to break the system down depends upon the criticality of the operation. It is generally advised to start at a high level and drill-down as required later in the process. 2. Identify the function(s) served by the equipment in achieving organizational goals. For example, in a stamping operation, a hydraulic press (equipment) must stamp material (function) for the organization to achieve its business objectives. 3. Identify potential failure modes. A pump failure is one way, or mode, in which a hydraulic system can fail to perform its designed function. Stakeholders in the organization often have varying views as to what defines a failed state. For instance, suppose an individual purchases a new sports car that has an advertised top-speed of 150 mph (241 k/hr). A visit to a test track by the proud new owner reveals that his vehicle is only capable of reaching 145 mph (233 k/hr). Technically, the vehicle has failed. Functionally, it has only failed if traveling at speeds greater than 145 mph (233 k/hr) is a bona fide requirement for the vehicle. 4. List the potential effects of failure. Different failure modes will have different effects on the organization. If the hydraulic pump craters, the pump ceases to function altogether. If the pump is worn over time, causing its volumetric efficiency to decline, the operation may be slowed or it may require more energy to accomplish the same level of work of a properly functioning pump. 5. Define the severity rating. For comparison and prioritization purposes, it is necessary to assign a failure severity rating to each occurrence. This refers to the relative impact of a failure on the operation with respect to downtime cost per hour and expected duration, repair costs, personal injury costs, environmental cleanup costs, and so on. The severity of failure is typically scaled on a one-to-ten basis, with one being the least and ten being the most severe. Each organization will have a unique definition of what is a short or a long down period. Generally, serial type operations are more sensitive to downtime than operations where multiple machines serve the same function and the loss of one machine only results in a fractional loss of production. There are numerous ways to arrive at a rating number for each failure mode but, for industrial applications, the consensus approach has proven to be costeffective. Table 13-1 illustrates a severity rating that is based upon the duration of downtime produced by the failure event.

13-5

EPRI Licensed Material Continuous Improvement Table 13-1 Severity Rating Duration of Downtime (Hours) Equal to or More Than

Less Than

Detection Rating

24

-

10

12

24

9

6

12

8

3

6

5

1

3

2

None

1

1

6. Define potential failure mechanisms. Sometimes called the “forcing functions,” failure mechanisms are why a particular failure mode might occur, or the underlying root causes of failure. For example, the failure mechanism cavitation can produce the failure mode pump failure, which can stop or slow production. 7. Assign an occurrence rating to each failure mechanism. Again using the one-to-ten scale, (one being least frequent, ten being most frequent), estimate how frequently each failure mechanism is likely to occur. Table 13-2 is an example of a system used to rate failure frequency. Table 13-2 Failure Occurrence Frequency Assessment Breakdown Frequency (Months) Equal to or More Than

Less Than

Detection Rating

12

-

10

9

12

9

6

9

8

3

6

5

1

3

2

None

1

1

8. Identify predictive techniques. Advanced warnings reduce the impact of a failure event by enabling management to schedule downtime, have parts and supplies on hand, and line up personnel with the appropriate skills to implement corrective actions. List the various techniques by which each failure might be detected.

13-6


9. Assign a detection rating to each failure mode/mechanism. Again using a one-to-ten scale (one being longer, ten being shorter), assess the effectiveness of the early warning systems (that is, oil analysis, vibration analysis, etc.) used. Table 13-3 provides one example of a detection warning period rating table. Table 13-3 Warning Period Rating Detection Warning Period Equal to or More Than

Less Than

Detection Rating

None

1 Day

10

1 Day

1 Week

9

1 Week

1 Month

8

1 Month

2 Months

5

2 Months

6 Months

2

6 Months

-

1

10. Assign a risk priority number (RPN). The RPN is calculated by multiplying the severity rating times the occurrence rating times the detection rating (Severity x Occurrence x Detection = RPN). The RPN rates the importance of each potential functional failure on a one-to-1000 scale, one being the lowest priority and 1000 being the highest. Although the technique is pseudo-quantitative, it is systematic and effective for the purposes of comparison and prioritization. Because it is based upon input numbers that are produced using a consensus, the derived RPN is also consensus-based. 11. Identify recommended maintenance action items. Based upon the nature and importance of the various failure modes and mechanisms, the cost to deploy detection techniques and technologies, and the RPN, action items are recommended. These items can range from equipment modifications to procedures for inspection. The Lube FMEA For most mechanical systems, the reliability engineer must define the lubricant as a critical component of the system because no shared-load system or spare exists for the function performed by the lubricant unless the host system is spared. Likewise, a lubrication failure can produce significant secondary damage to other system components. Because of the lubricant’s critical nature, and the frequency with which mechanical failure is related to the lubricating system, the term lubrication failure must be defined more precisely in the FMEA process to realize the full benefits of RCM.

13-7


The lube FMEA process begins with a system-specific evaluation of the lubricant’s functions as it relates to each piece of equipment, along with an assessment of the failure mechanisms that can impede effective lubrication functionality. Use the worksheet included in Figure 13-2 to apply the following process: The lube FMEA tasks are: 1. Define the functions that the lubricant is required to perform for each machine under investigation (these functions are defined in Table 13-4, Lubrication Functions). 2. Identify the lubrication-specific failure mechanism that might impede functional operation of the machine (these failure mechanisms are described in Table 13-5, Lubrication Failure Mechanisms). 3. Place an X in those boxes where the Lubrication Function and Lubrication Failure Mechanism intersect for a given machine. For example, lubricant degradation can’t degrade power and work transfer functionality in a bearing oil system because that function is specific to hydraulic machines. 4. For Causes or Failure Mechanisms, identify the specific lubrication-related failures that are the underlying root causes of failure modes that lead to a loss of system functionality. For instance, the specific lubrication failure mechanism, Particle Contamination Induced Loss of Power and Work Transfer Functionality, can cause loss of, or diminished, hydraulic system performance (failure mode), which disables the machine from its function (such as EHC valve sticking). 5. Complete the FMEA process as previously discussed. The Lube FMEA worksheet provides the lubrication specialist with a tool to use the general framework of FMEA to precisely define lubrication-related failure within the context of a machine’s function and contribution to meeting the company’s business objectives. By eliminating the practice of casually lumping technically unrelated failures into the category of lubrication failure, a new level of precision in maintenance and control over leading root causes of failure can be achieved.

13-8


Figure 13-2 Lube FMEA System Impact Assessment Worksheet

13-9


Lubrication Functions and Failure Mechanisms Table 13-4 Lubrication Functions Table Function

Description

Friction Control

By separating moving surfaces and providing boundary contact lubricity, the lubricant minimizes surface-to-surface friction. The appropriate selection of base-oil viscosity and type minimizes surface-to-fluid and fluid-to-fluid friction.

Wear Control

Minimizing surface-to-surface friction reduces wear. Controlling wear, of course, increases the useful life of components and machines.

Corrosion Control

Lubricant base-oil and additives coat machine surfaces to prevent the rust and corrosion of component surfaces.

Temperature Control

The lubricant absorbs thermal energy at the point of generation and transports it to a cooler or to the tank, where it can then dissipate.

Contamination Control

The lubricant picks up contaminants at the point of ingress and transports them to filters, dehydrators, separation tanks, etc., for removal. Also, the lubricant improves the effectiveness of seals.

Power and Work Transfer

In hydraulic systems, the fluid (which doubles as the lubricant) is the medium by which work is accomplished.

13-10

EPRI Licensed Material Continuous Improvement Table 13-5 Lubrication Failure Mechanisms Failure Mechanism

Description

Sudden Volumetric Loss

If the oil is on the floor, it can’t lubricate the machines or provide any of the functionality required of the lubricant. Typically, the lubricant hits the floor if the drain plug vibrates loose or if the drain valve fails. When this happens, the system loses lubrication functionality very quickly. Under normal circumstances, these failures would follow a random, or constant failure pattern. If the probability of the drain plug shaking loose increased over time, following a time-based wear out pattern, take action to make the event random. For example, create a PM to inspect and tighten on a regular basis, or redesign the system (that is, changing from a pipe thread-fitting to an O-ring-type fitting).

Failure to Fill

Starting a machine without oil is a sure way to cause a failure. This seems obvious, but it happens. Like sudden volumetric loss, failure to fill produces an immediate loss of lubricant functionality. This is an infant mortality type of failure that is easily prevented by following strict pre-start inspection procedures.

Low Levels

Some machines lose a little oil over time due to burning and/or leakage, potentially producing low-level conditions. Lubrication functionality is lost at varying rates when levels are low. For example, as the level drops, the oil’s ability to dissipate heat and air are progressively lost. Its ability to transfer power and work, however, may remain very steady until the level drops below the suction line, causing an immediate functional loss. Failures caused by low levels can be addressed by scheduling PMs to inspect and top-off, or by removing the cause of leakage or burning. If leakage is the culprit, there is the additional risk of slippage or fire hazard.

Wrong Lubricant

This is a common die young-type of failure that is tied to procedures. Adding the wrong oil to the system can produce numerous lubrication functional failures, depending upon the nature and severity of the infraction. A mild infraction such as using EP 320 instead of EP 460 gear oil will likely produce a mild effect. Conversely, adding oil that is not compatible with seals or a surface coating can have a very dramatic effect. This failure mechanism is avoided in a number of ways: educate the staff about the importance of getting the right lubricant in the system; attach easy to understand tags on lubricant-dispensing devices/systems; create procedures to ensure proper lubrication.

Base-Oil Degradation

Base-oil degradation typically follows a time-based wear out failure pattern. Although the lubricant’s properties tend to degrade in a steady pattern, most functional capabilities are retained until a critical threshold is passed and the lubricant is no longer capable of performing one or more of its designed functions. Base-oil degradation can be controlled proactively by minimizing exposure of the lubricant to heat, air, water, and metal catalysts. Oil analysis serves to alert the user of a degraded condition before the lubricant loses its functional capability.

13-11

EPRI Licensed Material Continuous Improvement Table 13-5 (cont.) Lubrication Failure Mechanisms Failure Mechanism

Description

Particle Contamination

Particle contamination primarily affects the lubricant’s ability to control friction and wear. Obstructing the separation of moving components and interfering with chemical oil films provided by anti-wear and EP additives, particle contamination can substantially increase the rate of abrasion, adhesion, and surface fatigue. The effects of particle contamination are slow and imperceptible. In fact, the loss of the lubricant’s functional ability to reduce wear and friction is often overlooked due to the slowness with which particle contamination degrades the system.

Moisture Contamination

Moisture contamination increases chemical wear by rusting iron and steel surfaces, and increasing the corrosive strength of resident acids attacking copper and lead surfaces. Vaporous cavitation and inhibited formation of elasto-hydrodynamic lubrication are among the contributions that water makes to increased mechanical wear. Moisture also degrades additives and speeds the rate of base-oil oxidation.

Fuel/Chemical Dilution

Process chemical and fuel contamination reduces the lubricant’s viscosity and dilutes its additive strength. Depending on the chemical contaminant and application, other complications range from chemical incompatibility with the lubricant, seals, coating or materials, to fire and safety hazard.

Coolant Contamination

Primarily a problem for engines and other glycol-cooled systems, coolant contamination produces a wide range of lubrication problems. Glycol produces an acidic environment, blocks oil flow passageways, increases wear, and encourages base-oil and additive degradation.

Additive Depletion

Some systems are more susceptible to functional lubrication problems caused by additive depletion than others. Turbine oil, for example, has a very simple but important additive package that tends to be stable under normal circumstances. Engines, on the other hand, contain very complex additive systems that are ever changing during operation.

Air Entrainment

Air entrainment can produce a number of functional lubrication failures, including increased oxidation, poor thermal transfer, gaseous cavitation, and spongy hydraulics. Likewise, some systems are more likely to incorporate air into the oil than other machines. Air dissipation effectiveness varies greatly depending upon lubricant viscosity, additive system, presence of contamination, and the size and design of the sump or tank.

Foaming

Foaming, like air entrainment, is more or less likely to occur depending upon the lubricant, the machine, and the application. Foam, when pumped to components, provides poor overall lubrication. By providing an abundant source of oxygen, and serving as an insulator to inhibit the dissipation of heat, foam increases the rate at which the lubricant oxidizes. The tank also produces a potential slippage or fire risk when the foam overflows.

Under-/Over-Greasing

For greased bearings, especially motors, too much grease may be as bad as too little. Over-greasing causes excessive heat generation in bearings. Likewise, grease pushes out into the motor cavities, which can contaminate windings and cause electrical problems.

13-12


The Concept of Continuous Improvement When considering continuous improvement as part of a comprehensive lubrication program, it must be understood that the continuous improvement effort is a journey and not a destination. It is a never-ending process of capturing learning experiences and implementing best practices.

13-13


14

REFERENCES

Section 2 Wurzbach, R., “Lubricant Consolidation and Specification Development,” Machinery Lubrication. Noria Publishing (January–February 2002). Figures: 2-3 and 2-7 courtesy Noria Publishing

Section 3 Editor, 2001 Gill Award, Practicing Oil Analysis. Noria Publishing (May–June 2000). Trujillo, G., J. Fitch, and D. Troyer. Machinery Lubrication Coursebook. Noria Publishing (2002). Williamson, M., “Designing the Optimum Lubricant Storeroom,” Practicing Oil Analysis. Noria Publishing (May–June 2000). Figures: 3-2, 3-6, 3-7, 3-8, 3-10, and 3-11 courtesy Noria Publishing

Section 4 Viramontes, J. and L. A. Harrington, “El Paso Electric Samples Cooling Tower Gearboxes,” Practicing Oil Analysis. (November–December 2001). Fitch, J. C., “Sampling Methods for Used Oil Analysis,” Lubrication Engineering. (March 2000). Fitch, J. C. and D. Troyer, Oil Analysis Coursebook. Noria Publishing 2002. Figures: 4-1 to 4-9 and Table 4-1 courtesy Noria Publishing

Section 5 Barnes, M., “Particle Counting—Oil Analysis 101,” Practicing Oil Analysis. Noria Publishing (July–August 2002).

14-1

EPRI Licensed Material References

Beesley, M., “Valve Stiction Problem Cured by Soft Particle Removal,” Practicing Oil Analysis. Noria Publishing (July–August) 2002. Duncanson, M., “Controlling Oil Aeration and Foam,” Practicing Oil Analysis. Noria Publishing (November–December 2001). Fitch, J. C., “Demystifying Sludge and Varnish,” Machinery Lubrication. Noria Publishing (January–February 2002). Fitch, J. C., “Vacuum Distillation for the Removal of Water and Other Volatile Contaminants,” Practicing Oil Analysis. Noria Publishing (March–April 2001). Fitch, J. C. and D. Troyer, Oil Analysis Coursebook. Noria Publishing 2002. Troyer, D., “Removing Water Contamination,” Practicing Oil Analysis. Noria Publishing (May– June 2001). Williamson, M., “Controlling Gearbox Contamination,” Machinery Lubrication. Noria Publishing (January–February 2002). Figures: 5-1, 5-3, 5-4, 5-7, 5-9, 5-10, 5-11, 5-14, 5-15, 5-20, 5-22, and Table 5-1 courtesy Noria Publishing

Section 6 Troyer, D. and Mark Barnes, “Goodbye Oiler, Hello Skilled Lube Tech and Lube Analyst,” Practicing Oil Analysis. Noria Publishing (January–February 2002). Figures: 6-1 to 6-3 courtesy Noria Publishing

Section 7 Fitch, J. C. and D. Troyer, Oil Analysis Coursebook. Noria Publishing 2002. Troyer, D., “Is Onsite Oil Analysis Right for Your Organization,” Practicing Oil Analysis. (March–April 2001). Williamson, M., “Establishing Effective Sampling Frequencies,” Practicing Oil Analysis. Noria Publishing (January–February 2001). Williamson, M., “Managing an Onsite Oil Analysis Program,” Practicing Oil Analysis. Noria Publishing (March–April 2002). Figures: 7-1 to 7-9, 7-12 to 7-14, and Table 7-3 courtesy Noria Publishing

14-2


Section 8 Garvey, R., “Get a Handle on Grease, Confirm Proper Lubrication Using Sonic/Ultrasonic Monitoring,” Practicing Oil Analysis. Noria Publishing (November–December 1999). Honeycutt, J., “Reducing Motor Bearing Failures—Modified Lubrication Procedures Improve Reliability at TVA,” Machinery Lubrication. Noria Publishing (May–June 2002). Neale, M. and D. Summers-Smith, Improving the Reliability of Machines by Understanding the Failure of their Moving Parts, Master Series Course Book. CSI, Knoxville, TN, October 1997. Robinson, J., J. Van Voorhis, K. Piety, and W. King, “Machinery Surveillance Employing Sonic/Ultrasonic Sensors,” Proceedings from Reliability Week, CSI, Knoxville, TN (1999). Smith, E. A., “Electric Motor Bearing Lubrication Faces New Challenges SKF USA Inc.,” Machinery Lubrication. Noria Publishing (July–August 2001). Figures: 8-1, 8-4, 8-7, 8-8, and 8-10 to 8-12 courtesy Noria Publishing

Section 9 Brigham, E. and L. Gapenski, Financial Management—Theory and Practice. The Dryden Press, Hinsdale, IL 1999. Fitch, J. C. and D. Troyer, Learning Oil Analysis Level II Course Book. Noria Corp, Tulsa, OK 1998. Johnson, B., H. Maxwell, and D. Hautala, “Predictive Maintenance - The Effect on a Company’s Bottom Line Performance,” Proceedings from the Practicing Oil Analysis Conference, Noria Corp, Tulsa, OK (1999). Troyer, D., “A Tutorial on Financial Project Justification Methods for the Oil Analysis Professional,” Proceedings from the Practicing Oil Analysis Conference, Noria Corp., Tulsa, OK (1999). VanDerHorn, G., “Beyond Detection—Realizing Value in a PdM Program,” Proceedings from the Reliability Week Conference, Computational Systems Inc., Nashville, TN (1997). VanDerHorn, G., “Communication—An Integral Part of Predictive Maintenance,” Proceedings from the Electric Power Research Institute’s 5th Predictive Maintenance Conference, Knoxville, TN (1992).

Section 10 Johnson, M., “How to Write a Top-Drawer Lubrication Procedure,” Machinery Lubrication. Noria Publishing (November–December 2001). 14-3


Moubray, J. Reliability Centered Maintenance, Second Edition. Industrial Press, Inc., New York, NY 1997, pg. 7. Moubray, J. Reliability Centered Maintenance. Second Edition. Industrial Press, Inc., New York, NY 1997, section 11.3, pg. 218. Rabinowicz, E. Friction and Wear of Materials, Second Edition. John Wiley and Sons, Inc., New York, NY 1995. Troyer, D., “Lubricant Condition Monitoring: A Proactive, Reliability Driven Approach,” Diagnetics, Inc. Tulsa, OK.

Section 11 Troyer, D., “Olé! Rallying for a New Lubrication Performance Metric,” Machinery Lubrication. Noria Publishing (July–August 2002). Figures: 11-1 courtesy Noria Publishing

Section 13 Cotnareanu, T., “Old Tools—New Uses: Equipment FMEA,” Quality Progress. pages 48–52 (December 1999). Moubray, J., Reliability-Centered Maintenance (RMC) II, Second Edition, Industrial Press Inc., New York, NY 1997. Rabinowicz, E., Friction and Wear of Materials, Second Edition, John Wiley and Sons, New York, NY 1995. Troyer, D., “How to Lube Up Your FMEA Process,” Practicing Oil Analysis. (May–June 2000). Figures: 13-1 to 13-5, and Tables 13-1, 13-2 courtesy Noria Publishing

14-4


A

PROCEDURE FOR INSTALLATION OF LUBRICATION OIL SAMPLING VALVE FITTINGS FOR PLANT EQUIPMENT

A-1

EPRI Licensed Material Procedure for Installation of Lubrication Oil Sampling Valve Fittings for Plant Equipment

1.0

PURPOSE

1.1

To provide instructions for four optional methods of installing oil sampling valve fittings in lubrication oil reservoirs or oil lube lines for rotating equipment. These methods are described in Section 5.0.

1.2

Section 5.0 of this procedure has been divided into the following subsections: 5.1 Installation Method No. 1 (Valve Only) 5.2 Installation Method No. 2 (Valve Plus Adapter Fittings) 5.3 Installation Method No. 3 (Valve in Lube Line Tee) 5.4 Installation Method No. 4 (Drill and Tap New Hole)

2.0

APPARATUS AND SPECIAL EQUIPMENT

2.1

Tools and Equipment

2.1.1

Thread inspection gauges

2.2

Materials NOTE: Materials may be substituted with approved equivalent items, except as noted.

2.2.1

Diagnetics Test Port # TP-250-L01 (oil sampling valve)

2.3

Consumables

2.3.1

Solvent

2.3.2

Pipe Thread Sealant

3.0

PRECAUTIONS AND LIMITATIONS

3.1

Precautions

3.1.1

Debris or foreign material introduced into systems has potential to cause equipment damage. Extreme care should be exercised in maintaining cleanliness and foreign material exclusion.

3.1.2

Ensure lubrication subsystem is drained properly if required to facilitate installation of sampling valves. Oil in system should NOT be allowed to spill.

3.1.3

Apply pipe sealant compound to external pipe threads of oil sampler valve and fittings as determined by Lead Maintenance Technician.

3.1.4

Supervision shall be notified immediately of abnormal “As Found” conditions and corrective actions taken shall be described in Remarks Section on last page of procedure.

3.2

Limitations

3.2.1

Oil sampling valves shall NOT be installed where operating temperature of sampling valve would be 350°F or greater.

A-2


3.2.2

Oil Sampling valves, which are installed by Method 3, Valve in Lube Line Tee, may affect plant drawings and should be reviewed for design configuration changes.

3.2.3

Oil sampling valves shall be clearly and properly labeled.

4.0

PREREQUISITES NOTE: Each installation method is pictured on the attachment with the corresponding number.

4.1

HAVE Responsible Engineer determine and indicate below method to be used: ( ) Method 1 - Valve only ( ) Method 2 - Valve and Adapter Fittings ( ) Method 3 - Valve in Lube Line Tee ( ) Method 4 - Drill and Tap New Hole Responsible Engineer

4.2

ENSURE installation option to be used has been documented in Computerized Maintenance Management System (CMMS).

4.3

RECORD the following: Work Order No.: Equipment ID No.: Plant Location:

4.4

OBTAIN appropriate clearances as prescribed in Work Order.

4.5

ENSURE that Post Maintenance Testing (PMT) is included as part of this work package to ensure adequacy of installations against leakage of lubrication oil due to a faulty operation of sampling valve or leakage past pipe threads.

4.6

Prerequisites complete, precautions and limitations understood.

5.0

PROCEDURE

5.1

Installation Method No. 1 (Valve Only) Subsection Required: YES

NO

5.1.1

CLEAN existing plug and surrounding area.

5.1.2

INSPECT sampling valve and removable cap for damage and presence of O-ring at bottom of threads in cap and for O-ring inside hole of straight threaded end of valve body.

A-3


Damaged

YES

NO

O-ring in cap

YES

NO

O-ring in body

YES

NO

NOTE: As cap is threaded on to valve body a slight resistance will be felt as end of valve body encounters O-ring inside cap. Cap is NOT installed until a solid stop is felt. CAUTION Cap is a straight thread with O-ring and may be damaged by tightening with a wrench. 5.1.3

INSTALL Cap. CAUTION Drain container should be large enough to accommodate quantity of oil which will escape when plug is removed.

5.1.4

PLACE temporary drip pan under drain plug.

5.1.5

REMOVE existing drain plug.

5.1.6

INSPECT internal pipe threads for non-oil type dirt; wipe or brush threads clean as necessary.

5.1.7

INSTALL oil sampling valve AND TIGHTEN to ensure leak tightness.

5.1.8

FILL lubrication oil reservoir with proper lubrication oil to appropriate level. RECORD lubrication type below. Lubricant added:

5.1.9

INSPECT installation for the following: YES

NO

Leakage at valve with cap removed YES

NO

Cross threading

YES

NO

Cap installed hand tight

YES

NO

Oil leakage at pipe thread

5.1.10 INITIAL indicating this subsection complete. 5.2

Installation Method No. 2 (Valve Plus Adapter Fittings) Subsection Required: YES

5.2.1

A-4

NO

CLEAN existing plug and surrounding area.


5.2.2

INSPECT sampling valve and removable cap for damage and presence of O-ring at bottom of threads in cap and for O-ring inside hole of straight threaded end of valve body. Damaged

YES

NO

O-ring in cap

YES

NO

O-ring in body

YES

NO

NOTE: As cap is threaded on to valve body a slight resistance will be felt as end of valve body encounters O-ring inside cap. Cap is NOT installed until a solid stop is felt. CAUTION Cap is a straight thread with O-ring and may be damaged by tightening with a wrench. 5.2.3

INSTALL Cap. CAUTION Drain container should be large enough to accommodate quantity of oil which will escape when plug is removed.

5.2.4


5.2.5

REMOVE existing drain plug.

5.2.6

INSPECT internal pipe threads for non-oil type dirt; wipe or brush threads clean as necessary. NOTE: Adapters shall be installed at minimum length necessary to install and use oil sampling valves. Refer to Noria Sampling Wall Chart for guidance in proper installation.

5.2.7

INSTALL adapters AND TIGHTEN to ensure leak tightness.

5.2.8

INSTALL oil sampling valve AND TIGHTEN to ensure leak tightness.

A-5


5.2.9

FILL lubrication oil reservoir with proper lubrication oil to appropriate level. RECORD lubrication type below. Lubricant added:

5.2.10 INSPECT installation for the following: YES

NO


NO

Cross threading

YES

NO


YES

NO



Installation Method No. 3 (Valve in Lube Line Tee) Subsection Required: YES

NO

NOTES: Location and orientation to be determined by Responsible Engineer. Location should allow sufficient clearance to account for thermal movement. Tee and fitting should be located as close as possible to existing piping supports. Refer to Noria Sampling Wall Chart for guidance in proper installation. 5.3.1

DETERMINE location and orientation required to install tee in line.

5.3.2

CLEAN lubrication line in region where tee is to be installed. CAUTION Drain container should be large enough to accommodate quantity of oil which will escape when plug is removed.

5.3.3


5.3.4

REMOVE existing drain plug. NOTE: As cap is threaded on to valve body a slight resistance will be felt as end of valve body encounters O-ring inside cap. Cap is NOT installed until a solid stop is felt.

A-6


5.3.5

INSPECT sampling valve and removable cap for damage and presence of O-ring at bottom of threads in cap and for O-ring inside hole of straight threaded end of valve body. Damaged

YES

NO

O-ring in cap

YES

NO

O-ring in body

YES

NO CAUTION

Cap is a straight thread with O-ring and may be damaged by tightening with a wrench. 5.3.6

INSTALL Cap. NOTE: Lubrication lines may be either welded or threaded. Tee fittings and any adapters added to lubrication lines shall conform to plant piping requirements. Size of tee fittings shall be compatible with existing piping or tubing and oil sampler valve. Oil sampling fittings may be connected to either run or branch sides of tee as required by equipment configuration. Refer to Noria Sampling Wall Chart for guidance in proper installation.

5.3.7

MODIFY existing lubrication lines as required to install tee adapter fitting by performing appropriate method below.

1.

Existing lubrication line fabricated from welded pipe: a. REMOVE pipe run from equipment. b. FLUSH with solvent to remove all traces of oil. c. CUT pipe to match required tee location. d. INSPECT all piping and tees for proper cleanliness prior to assembly. SAT

UNSAT

e. ASSEMBLE piping assembly with new tee installed. Welding shall be performed in accordance with plant procedures and regulations. 2.

Existing lubrication lines fabricated from threaded pipe: a. DISASSEMBLE pipe lines from nearest unions. b. REMOVE pipe that is to contain tee adapter from assembly. c. CUT pipe to match required tee location. d. FABRICATE threads. e. ASSEMBLE piping assembly with new tee installed to orientation shown in Attachment 3.

A-7


f. INSPECT all piping and tees for proper cleanliness prior to installation. SAT

UNSAT

g. INSTALL piping assembly onto equipment. 3. Existing lubrication line fabricated from tubing: a. CUT existing lubrication line at required location. b. DEBURR tubing ends as necessary. c. REMOVE all metal chips from tubing. d. FLUSH tubing with solvent. e. INSTALL tee tube fitting. 5.3.8

INSTALL adapter fitting(s) if required.

5.3.9

INSTALL oil sampling valve and TIGHTEN to ensure leak tightness.

5.3.10 FILL lubrication oil reservoir with proper lubrication oil to appropriate level. RECORD lubrication type below. Lubricant added: 5.3.11 INSPECT installation for the following: YES

NO


NO

Cross threading

YES

NO


YES

NO


5.3.12 NOTIFY Engineer that an Engineering Change may need to be submitted showing asbuilt condition and changes to piping diagrams. 5.3.13 INITIAL indicating this subsection complete. 5.4

Installation Method No. 4 (Drill and Tap New Hole) Subsection Required: YES

NO

NOTE: Location to be determined by Responsible Engineer. 5.4.1

DETERMINE location of new sampling valve hole.

5.4.2

PLACE temporary drip pan under reservoir.

5.4.3

DRAIN oil reservoir.

5.4.4

IF oil reservoir contains access openings, THEN REMOVE access opening covers to provide accessibility for cleaning and chip removal.

A-8


NOTE: If it is determined that sampling valve is to be attached directly to oil reservoir, 1/4 - 18 NPT threads shall be tapped in side of reservoir. If it is determined that adapter bushings shall be used, drill and tap appropriate thread size into reservoir. Refer to Noria Sampling Wall Chart for guidance in proper installation. 5.4.5

DRILL AND TAP pipe threads to appropriate size and location as determined by Responsible Engineer. NOTE: Generation of metal chips and debris in reservoir can be minimized by the use of a drill stop, set at a distance slightly less than the thickness of the surface being drilled. After cleaning debris, the drill stop can be removed, and a magnetized bit used to minimize debris entering the reservoir.

5.4.6

DEBURR both ends of tapped hole.

5.4.7

REMOVE all metal chips from lubrication oil reservoir.

5.4.8

FLUSH reservoir with solvent, if considered necessary by Lead Maintenance Technician. REMOVE all solvent from reservoir. CLEAN reservoir.

5.4.9

FLUSH reservoir with oil.

5.4.10 INSPECT region around tapped hole and inside reservoir for cleanliness (chip removal) and solvent removal. SAT

UNSAT

5.4.11 INSPECT tapped hole for proper size and depth and condition of threads. SAT

UNSAT

5.4.12 INSPECT sampling valve and removable cap for damage and presence of O-ring at bottom of threads in cap and for O-ring inside hole of straight threaded end of valve body. Damaged

YES

NO

O-ring in cap

YES

NO

O-ring in body

YES

NO

NOTE: As cap is threaded on to valve body a slight resistance will be felt as end of valve body encounters O-ring inside cap. Cap is NOT installed until a solid stop is felt. CAUTION Cap is a straight thread with O-ring and may be damaged by tightening with a wrench. 5.4.13 INSTALL Cap. NOTE: Adapters shall be installed at minimum length necessary to install and use oil sampling valves. A-9


Location, orientation, and choice of adapters to be determined by Responsible Engineer. Refer to Noria Sampling Wall Chart for guidance in proper installation. 5.4.14 INSTALL adapter fitting(s) if required. 5.4.15 INSTALL oil sampler valve AND TIGHTEN to ensure leak tightness. 5.4.16 INSTALL access covers removed in Step 5.4.4. 5.4.17 FILL lubrication oil reservoir with proper lubrication oil to appropriate level. RECORD lubrication type below. Lubricant added: 5.4.18 INSPECT installation for the following: YES

NO


NO

Cross threading

YES

NO


YES

NO



RETURN TO NORMAL

6.1

Lead Maintenance Technician, VERIFY tools and equipment are returned to designated storage location and work area is clean.

7.0

REFERENCES

7.1

Vendor/Technical Manuals

7.1.1

Diagnetics Inc., Drawing No. 2690

7.1.2

Noria Sampling Wall Chart

A-10


B

TEST SLATES

Test Slates Test Slates are templates of standard analysis tests to be performed on given equipment types. Every plant should develop its own set of Test Slates because they are a reflection of the operational, environmental, and service conditions that each machine faces when in use in each particular situation. Example Test Slates can serve as foundations for creating a plant’s own Test Slates for use in defining the given set of analysis tests to be performed on each sample sent for analysis. The Test Slates include both routine and exception tests. The routine tests are performed on each sample sent to the laboratory for analysis. Exception tests are performed when the established test limits are exceeded for a given test. In the tables shown in this Appendix, exception tests are marked, along with a number or numbers, in parentheses. The number refers to the test that will prompt that exception test to be performed, by virtue of having exceeded the limits of the routine test. For example, in the Test Slate—Air and Gas Compressors, Test Number 9, Analytical Ferrography is listed as an exception test. The parentheses indicate that it will be performed when the limits are exceeded for either Test Number 8, Ferrous Density, or Test Number 14a, Elemental Analysis—Wear Metals. Test Slates are developed to optimize the number and types of tests that are performed on each sample. Whether analysis is performed in-house, or at a corporate lab, or if it is sent to an outside contract lab, the performance of unnecessary or inappropriate tests is a waste of resources. However, when important tests are not performed on a specific equipment type, then the full potential value of oil analysis is not harvested. Establishing site-specific Test Slates will result in optimization of the value of the data for the oil analysis program.

B-1

EPRI Licensed Material Test Slates

Reference 1-B: Test Slate—Steam Turbine Oils 1. Particle Count

Routine

2. Viscosity a. 40°C

Routine

b. 100°C 3. TAN

Routine

4. TBN 5. FTIR a. Ox/Nit/Sul

Routine

b. Hindered Phenol

Routine*

c. Aromatic Amine

Routine*

d. ZDDP e. Fuel Dilution/Soot 6. Flash Point

Exception (2b, 5d)

7. Glycol - ASTM Test 8. Ferrous Density

Exception (1)

9. Analytical Ferrography

Exception (8, 14a)

10. RPVOT

Routine

11. Crackle 12. Water by Karl Fischer 13. Water Separability 14. Elemental Analysis a. Wear Metals

Routine

b. K, Na, B, Si

Routine

c. Additives

Routine

Routine = Routine Testing Exception = Exception test keyed to a positive result from the test in parentheses. *If these are not available from FTIR, RULER testing can be substituted.

B-2


Reference 2-B: Test Slate—Gas Turbine Oils 1. Particle Count

Routine


Routine

b. 100°C 3. TAN

Routine


Routine

b. Hindered Phen c. ZDDP d. Fuel Dilution/Soot 6. Flash Point

Exception (2b, 5d)

7. Glycol—ASTM Test 8. Ferrous Density

Exception (1)


Exception (8, 14a)

10. RBOT

Routine

11. Crackle 12. Water by Karl Fischer 13. Water Separability 14. Elemental Analysis a. Wear Metals

Routine

b. K, Na, B, Si

Routine

c. Additives

Routine

Routine = Routine Testing Exception = Exception test keyed to a positive result from the test in parentheses.

B-3


Reference 3-B: Test Slate—Diesel and Gas Engines 1. Particle Count

Routine

2. Viscosity a. 40°C b. 100°C

Routine

3. TAN 4. TBN

Routine

5. FTIR a. Ox/Nit/Sul

Routine

b. Hindered Phen c. ZDDP d. Fuel Dilution/Soot

Routine

6. Flash Point

Routine

7. Glycol—ASTM Test

Exception (14b)

8. Ferrous Density

Routine


Exception (8, 14a)

10. RBOT 11. Crackle

Routine

12. Water by Karl Fischer

Exception (11)

13. Water Separability 14. Elemental Analysis a. Wear Metals

Routine

b. K, Na, B, Si

Routine

c. Additives

Routine


B-4


Reference 4-B: Test Slate—Motor and Pump Bearings 1. Particle Count

Routine


Routine

b. 100°C 3. TAN

Exception (5a)


Routine

b. Hindered Phen

Routine

c. ZDDP

Routine

d. Fuel Dilution/Soot 6. Flash Point 7. Glycol—ASTM Test 8. Ferrous Density

Exception (1)


Exception (8, 14a)


Routine


Exception (11)


Routine and Exception (1)

b. K, Na, B, Si

Routine

c. Additives

Routine


B-5


Reference 5-B: Test Slate—Industrial Gear Oils 1. Particle Count

Routine


Routine

b. 100°C 3. TAN

Routine


Routine

b. Hindered Phen

Routine

c. ZDDP

Routine


Routine


Exception (8, 14a)


Routine


Exception (11)



b. K, Na, B, Si

Routine

c. Additives

Routine


B-6


Reference 6-B: Test Slate—EHC Fluids* 1. Particle Count

Routine


Routine

b. 100°C 3. TAN

Routine

4. TBN 5. FTIR a. Ox/Nit/Sul b. Hindered Phen c. ZDDP d. Fuel Dilution/Soot 6. Flash Point 7. Glycol—ASTM Test 8. Ferrous Density

Routine


Exception (8, 14a)


Routine


Exception (11)



b. K, Na, B, Si

Routine

c. Additives

Routine

*For phosphate ester fluids, consult fluid supplier and/or turbine manufacturer Routine = Routine Testing Exception = Exception test keyed to a positive result from the test in parentheses.

B-7


Reference 7-B: Test Slate—Babbitt Bearings on Fans, Motors, and Pumps 1. Particle Count

Routine


Routine

b. 100°C 3. TAN

Routine


Routine

b. Hindered Phen c. ZDDP d. Fuel Dilution/Soot 6. Flash Point 7. Glycol—ASTM Test 8. Ferrous Density 9. Analytical Ferrography

Exception (14a)

10. RBOT

Routine

11. Crackle

Routine


Exception (11)


Routine

b. K, Na, B, Si

Routine

c. Additives

Routine


B-8


Reference 8-B: Test Slate—Air and Gas Compressors 1. Particle Count

Routine


Routine

b. 100°C 3. TAN

Routine


Routine

b. Hindered Phen

Routine

c. ZDDP

Routine

d. Fuel Dilution/Soot 6. Flash Point

Routine—Gas Compressors Only

7. Glycol—ASTM Test 8. Ferrous Density

Routine


Exception (8, 14a)

10. RBOT

Routine

11. Crackle

Routine—Air Compressors Only


Exception (11)—Air Compressors Only

13. Water Separability

Routine—Air Compressors Only

14. Elemental Analysis a. Wear Metals


b. K, Na, B, Si

Routine

c. Additives

Routine


B-9


Reference 9-B: Test Slate—Chillers and Refrigeration 1. Particle Count

Routine


Routine

b. 100°C 3. TAN

Routine


Routine

b. Hindered Phen c. ZDDP d. Fuel Dilution/Soot 6. Flash Point 7. Glycol—ASTM Test 8. Ferrous Density

Routine


Exception (8, 14a)


Routine


Exception (11)



b. K, Na, B, Si

Routine

c. Additives

Routine


B-10


Reference 10-B: Test Slate—Vacuum Pumps 1. Particle Count

Routine


Routine

b. 100°C 3. TAN

Routine


Routine

b. Hindered Phen

Routine

c. ZDDP

Routine


Routine


Exception (8, 14a)


Routine


Exception (11)

13. Water Separability

Routine

14. Elemental Analysis a. Wear Metals


b. K, Na, B, Si c. Additives

Routine


B-11


C

TRICO MANUFACTURING CORP. TECHNICAL REFERENCE FOR TRICO OILERS

C-1

EPRI Licensed Material Trico Manufacturing Corp. Technical Reference for Trico Oilers

C-2

EPRI Licensed Material Trico Manufacturing Corp. Technical Reference for Trico Oilers

C-3

Target: Plant Maintenance Optimization

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Lube Oil Predictive Maintenance Handling, And Quality Assurance Guideline

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