Policies & Procedures LPMN Yemen Policies & Procedures All
Manual:
E & C - Facility Engineering
No.: 630-60001-01
Sub-title:
Specification\Mechanical
Version: 4
Procedure:
Pressure Safety Valve (PSV)
Policy Detail
CANADIAN NEXEN YEMEN Canadian Nexen Petroleum Yemen Ltd (CNPY) & Canadian Nexen Petroleum East Al Hajr Ltd (CNPE)
Pressure Safety Valve (PSV) Procedure
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TABLE OF CONTENTS 1.
PURPOSE
2.
SCOPE
3.
REFERENCE(S)
4.
DEFINITION(S)
5.
RESPONSIBILITIES
6.
PROCEDURE(S)
7.
DOCUMENTATION / RECORDS KEEPING
8.
ATTACHMENT(S)
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1. PURPOSE This procedure provides a guideline for the design, procurement, installation, testing, operation and maintenance of Pressure Safety Valves (PSV’s). Record keeping is an integral component of this procedure. 2. SCOPE This procedure defines the life cycle of the PSV. The life cycle starts with design and continues through purchase, installation, operation and maintenance. PSVs are Safety Critical equipment unless noted otherwise. The following pressure relief devices are NOT included within the scope of this procedure: Rupture disks Venting and breathing equipment for low pressure above ground storage tanks 3. REFERENCE(S) API RP 520 Part 1 Part 2
– Sizing and Selection – Installation
API STD 526
– Flanged steel pressure relief valves
API STD 527
– Seat tightness of Pressure Relief Valves
API RP 576
– Inspection of Pressure Relieving Devices
ASME VIII D1
– Rules for Construction of Pressure Vessels
ASME B 31.3
– Process Piping
ASME B 31.4 ASME B 31.8
– Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids. – Gas Transmission and Distribution Piping System
Crosby Pressure Relief Valve Engineering Handbook (now out of Date) Nexen Inc. No. 1111
- Removal/installation of PSVs from Operational Plant
Nexen Inc. No. 1208
- Safety Critical Equipment PM Deferment Procedure
PSV Maintenance Practice
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4. DEFINITION(S) Batch List: A list of Batch PSVs Batch PSVs: Common PSVs for use in multiple locations such as receivers or launchers and typically have a Maintenance Plan with a 4 year cycle. The technical ID is generic i.e. PSV-XXXX and may or may not be shown on a P&ID. These PSVs are rated by Engineering, maintained by Maintenance and typically removed/installed by Production in batches. Cold differential test pressure (CDTP) - the inlet static pressure at which a pressure relief valve is adjusted to open on the test stand. This test pressure includes corrections for service conditions of superimposed back pressure and/or temperature. *NOTE: Set Pressure and CDTP are assumed the same unless specified otherwise. Maintenance Plan: SAP Process assigned to equipment which defines repetitive work in terms of a Task List and Cycle period. The Task List describes the work steps. The Cycle period for PSVs is either 2 or 4 years. MWO: Maintenance Work Order Pilot Operated PSV: Pressure relief valve in which the major relieving device or main valve is combined with and controlled by a self actuated auxiliary pressure relief valve (pilot). PM: Preventative Maintenance activities and frequency defined by a Maintenance Plan. PM MWO: Is the Maintenance Work Order Document which includes the Pressure Relief Valve Inspection / Test Sheet and the PSV Service Record for the PSV requiring Maintenance. Popping pressure - the value of increasing inlet static pressure at which the disc moves in the opening direction at a faster rate as compared with corresponding movement at higher or lower pressures. It applies only to safety or safety relief valves on compressible-fluid service. Pressure Relief Valve Inspection / Test Sheet: Is the record used to document PSV Test requirements (API 527 and 576) and Test results. This is a component of the PM MWO for PSVs. A hard copy shall be retained by Planning. 4
PSV: Pressure Safety Valve or Pressure Relief Valve. PSV Service Record: a document attached to the PM MWO by the Maintenance Technician when a PSV, requiring a PM, is replaced by a spare PSV. RCA: Root Cause Analysis Set Pressure: the value of increasing inlet static pressure at which a pressure relief valve displays one of the operational characteristics as defined under opening pressure, popping pressure, or start-to-leak pressure Spring Loaded Pressure Safety Valve: Spring loaded pressure relief valve actuated by the static pressure upstream of the valve and characterized by rapid opening or pop action. There are two types of spring loaded PSVs: • Conventional PSV; Spring loaded pressure relief valve whose operational characteristics are directly affected by changes in the back pressure. • Balanced PSV; Spring loaded pressure relief valve that incorporates a bellows or other means for minimizing the effect of back pressure on the operational characteristics of the valve. Storage: PSVs not immediately placed into service are considered to be in storage. Storage may be in the Logistics warehouse, PSV Test shop or held in another facility on site. 5. RESPONSIBILITIES 5.1 E&C is responsible for ensuring that the PSV is designed to perform the required function. E&C will prepare the Purchase Requisition and ensure any ordered PSV will have spare parts and all the necessary technical documents. E&C is also responsible for installing new PSVs in all new or modified facilities. 5.2 Logistics is responsible for bidding the PSVs and placing the Purchase Order with a qualified vendor approved by E&C. Logistics will ensure packaging, handling, transportation and storage of the PSVs is performed properly. Logistics will ensure all the required documents of the PSV is received and delivered to the end user of the PSV and will also maintain an inventory of spare parts as requested by Maintenance. 5.3 Maintenance Maintenance is responsible for inspecting, ordering spare parts, testing, calibrating, repairing, replacing, reinstalling, tracking, and conducting all the PM services for all PSVs. The Mechanical Plant Superintendent shall insure all PSV failures are investigated for their prevention and re-occurrence (see 6.6.5.2). 5
Where chronic repeat failures occur, a RCA shall be completed to remedy this condition. 5.4 The PSV owner is responsible to ensure/verify the New or replacement PSV is placed in the correct location. 5.5 The PSV owner is responsible for operating and On-Line Visual inspection of all PSV installations and ensuring that car seals are properly installed. 5.6 Production removes and replaces thermal relief PSVs on pig launchers and receivers (Batch PSVs) under the Supervision (Auditing) of Maintenance to insure correct transportation and handling (see 6.6.3 & 6.6.4) 6. PROCEDURE(S) 6.1 Design 6.1.1 The design of PSVs is driven by the requirement for protecting certain pressure equipment against overpressure that may occur during the normal operation or any abnormal event like fire. Sizing and specifying a PSV is an exhaustive engineering task, which is beyond the scope of this procedure. Generally, all safety relief PSVs shall be designed, manufactured, stamped, and installed in accordance with the relevant section of the ASME Boiler and Pressure Vessel Codes and API RP 520. 6.1.2 When all the required data of a PSV is known, the Specification Sheet (Attachment 1) of the PSV can be filled in with the summary of all engineering calculation data. 6.1.3 PSV identification at this stage follows the tagging of the P&ID for the area where the PSV is installed. The Drafting Department controls numbering of all the PSVs. PSV identification should be indicated in the specification sheet and will become a significant reference number in the operation and maintenance activities of a PSV.
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6.1.4 In order to facilitate PSV tracking and in service inspection of thermal relief PSVs on the Launcher / Receiver field installations, these PSVs will have a simplified form of P&ID tagging. They will follow the alphabetic suffix of piping specs, which is related to ANSI/ASME flange rating classification. The following table indicates the flange rating and PSV setting for each PSV category. Symbol
ANSI Class #
Design Pressure (PSI@100°F)
Thermal relief PSV tag
A
150
285
PSV-XXXXA
B
300
740
PSV-XXXXB
C
600
1480
PSV-XXXXC
D
900
2220
PSV-XXXXD
E
1500
3000
PSV-XXXXE
6.1.5 PSVs on pressure equipment shall have locked-open inlet and outlet block valves. Each PSV shall have a vent bypass to facilitate relief valve maintenance and testing. Relief headers shall be sloped toward disposal to avoid accumulation of liquid. 6.1.6 Relief discharge lines, other than thermal relief of non-flashing liquids, shall tie in to either dedicated relief tank or pit/flare. PSV discharge lines shall not tie into drain systems. 6.2 Procurement 6.2.1 A Purchase Requisition is created by the project engineer to order a certain PSV. The PSV Specification Sheet should be attached to the Purchase Requisition. The Purchase Requisition would request the manufacturer to provide: • Two years of normal spare parts. This should include at minimum one gaskets kit and O-rings. • Technical Documentation: • The Engineered Service Specification Sheet, • Manufacturers/Assemblers Test Report • Manufacturers/Assemblers Bill of Materials/Parts List of internal components 7
6.2.2 Packing, crating, and shipping instructions are specified in the “Instructions to Sellers” supplied with the "Request for Quotation." Modifications to those instructions will be contained in the Purchase Order, if applicable. 6.2.3 The documentation for a PSV shall be received with the PSV and must remain in its packaging under Logistics control until the PSV is issued to the end user. 6.3 PSV Maintenance Planning Requirements for New Installations 6.3.1 When a new PSV is received by Logistics for a project, it is forwarded to the end user (in most cases E&C Department). The original of the technical documentation must be give to E&C Document Control. 6.3.2 When a new PSV is received by Logistics for inventory replenishment, it is retained in stock until withdrawn by Maintenance. 6.3.3 The end user takes it to Maintenance Department for Pop testing or Inspection and Testing. 6.3.4 The requester for new PSV testing, shall provide a copy of all the required technical documentation about this new PSV to the Maintenance Planning Dept. The PSV shall be accompanied with its pertinent P&ID drawing indicating the location of the PSV. 6.3.5 Maintenance Planning shall give new PSVs an SAP equipment number and input all the PSV data as per the Specification Sheet into SAP. SAP equipment number is unique to the PSV serial number and is the only method of tracking the history of a PSV. 6.3.6 Engraved stainless steel tags will be attached to the PSV. Maintenance Planning attaches a tag which indicates SAP equipment number. Maintenance PSV Shop attaches another tag indicating set pressure and calibration date. 6.3.7 A MWO is created for Maintenance PSV Shop to conduct a Pop Test or Inspection and Test as per 6.6.6 (PSV Inspection and Testing) as applicable. Disposable PSVs cannot be Inspected and Tested, so they are only Pop tested. Typical PSVs are not Pop tested as they can be Inspected and Tested (Overhauled). 6.3.8 Test results shall be recorded in the PSV Shop Log Book. The Pressure Relief Valve Inspection / Test Sheet shall be completed and the PSV tagged with the test date. The Pressure Relief Valve Inspection / Test Sheet is attached to the MWO, and returned to Maintenance Planning with the PSV. The end user collects the PSV from the Maintenance Planning office or Maintenance PSV shop. 6.3.9 Maintenance Planning will assign the relevant PM or maintenance plan for; 8
6.3.9.1 Inspection and Testing of the PSV based on the proper inspection interval. 6.3.9.2 Annual (12 month) Visual Inspections (see 6.6.1.1). 6.3.10 If required, Maintenance Planning will assign a storage location to the PSV pending the PSV installation into its final Functional Location. 6.4 Installation for New and Spare PSV’s CAUTION! Before any PSV or Spare PSV is returned to service a visual inspection to verify cleanliness of visible internal component shall be completed. If the PSV has not been used within 28 days from the date of the Date tag, the PSV must be pop tested one time. 6.4.1 All PSV’s shall be installed as specified and in accordance with P&ID and piping drawings, installation details, and established Safe Work Practices and Procedures. Upon installing a PSV, the installing Department must advise Maintenance Planning of the SAP equipment number and the Functional Location. Planning will transfer the PSV into the new Functional Location in SAP. This will ensure the location of the PSV is known when the next PM of the PSV is scheduled. 6.4.2 The requirements for transporting and installation of PSVs is given in 6.6.3 and 6.6.4 (PSV Removal and installation & Transportation of PSVs). 6.4.3 The E&C Department shall install new PSVs into their Functional Location (new project or ESR). 6.4.4 The Maintenance Department shall remove, install or replace existing PSVs except for Batch PSVs. 6.4.5 The Production Department shall remove and install Batch PSVs. Maintenance will supervise this activity to insure compliance with Handling and Transportation of PSVs 6.4.6 Maintenance Planning is responsible to determine the remaining cycle time before installing a Spare PSVs. The Spare PSV are generally installed within 1 months of the test date. PSVs which have been in storage for a long time may require the Maintenance Planner to schedule Inspection and Test prior to installation. See PSV Storage 6.6.7 Example; PSVs on a 2 year Cycle installed on the same date as Inspection and Testing will not to be overdue until 2 years and 3 months (per Safety Critical Equipment PM Deferment Procedure). 9
If the spare PSV is installed 6 month after Inspection and Testing, the PSV can be in service for 21 months before it is overdue. 6.5 Operation 6.5.1 When pressure equipment is handed over to Owner Department, a series of checks need to be made prior to commissioning the equipment. PSVs are an essential part of the Process Safety Management system and the PSV installation, whether it is newly installed or reinstalled after maintenance work, should be checked prior to commissioning. 6.5.2 PSV piping components including upstream and downstream block valves should be checked and car sealed open and the by-pass PSV must be car seal closed prior to commissioning. 6.5.3 Visual on-stream inspections shall be performed (see 6.6.1.1). 6.5.4 PSVs shall not be isolated or removed from operating pressurized equipment unless specially authorized to do so. In this case, if the PSV must be removed, an Impairment Permit must be completed and approved. 6.5.5 Prior to Maintenance work on a PSV, the pressurized equipment shall be isolated completely from the process, by blocking in the isolation valves per Nexen’s Lock Tag and Try Procedure. 6.5.5 Prior to removing the PSV, the inlet block valve shall be closed before the outlet block valve is closed. The PSV must then be depressurized before the PSV is removed. 6.6 Maintenance 6.6.1 Types of Maintenance 6.6.1.1
The Visual On-Stream inspection is to verify the PSV condition. At minimum, the following activity shall be performed on all PSVs annually. Findings shall be recorded to the PM MWO.
6.6.1.2
At the correct location as confirmed by records/data. Confirm Date and Equipment tags. Piping is not strained. No external damage or leaks are detected. All Block valves around a PSV must be Car Sealed open.
Routine Maintenance PM of PSVs is referred to as “Inspection and Testing”. 10
6.6.2 Inspection Interval • Engineered and HGOR thermal PSV’s: every two years since date of last Inspection and Test. • All other thermal relief PSV on Field Launcher/Receiver installations: every four years since date of last Inspection and Test. • May be set on review of in-service performance. procedure shall apply.
The MOC
• The SAP Maintenance Plan’s cycle time, for each PSV, will start on the same day as when the PSV has been tagged with the Test and Date following Inspection and Testing. 6.6.3 PSV Removal and installation: Caution! A PSV shall not be removed until properly tagged and identified except for the following case; an untagged PSV can only be removed if all three following conditions are met; 1. The PSV’s Serial number, manufacturer and the physical dimensions match the PSV information on the MWO 2. This condition has been communicated to the Foreman. 3. The Foreman has confirmed the untagged PSV can be removed. If the PSV does not match the MWO information, the PSV must remain in location until it has been reviewed by Maintenance Planning. • When the PSV is removed, inlet and outlet piping shall be inspected for the presence of internal deposits, and records shall be kept of their condition. • If heavy fouling is observed, the cause for this condition shall be investigated and corrected to prevent reoccurrence. It is the responsibility of the Maintenance Department to address this concern. • Before a PSV is installed, the flanges on the mounting nozzle shall be thoroughly cleaned to remove any foreign material that may cause leakage. Caution! Where PSVs are too heavy to be readily lifted by hand, the use of proper handling devices shall be used to avoid damage to gasket faces. Ring 11
joint flanges shall be handled with extreme care so that the mating sections are not damaged. • Bolting shall be in accordance with ASME B31.3, ASME B31.4, or ASME B31.8 as applicable. • Flange bolt holes shall straddle the flange centre line. Stud bolt threads shall be lubricated with a graphite thread lubricant before installation of nuts. • Threaded pipe connections to a PSV shall be installed as shown on piping plans, sections, and isometrics. • Ends of pipe shall be cut square and reamed. • Threads shall be cut using thread cutting lubricant and shall be straight and to proper length. • Threads shall be wire-brushed to remove burrs. • All damaged or substandard threads shall be rethreaded. • All threaded connections shall be made up tight using tetrafluoroethylene (TFE) tape or approved equal on male threads only. • Threaded unions shall not be installed in straight runs but in offsets to facilitate installation and removal.
6.6.4 Transportation of PSVs Caution! PSVs are delicate equipment and serve to protect Life and Property. Handle carefully to prevent damage. • PSV handling and transport shall comply with good workmanship and accepted industry practice. The PSV shall be treated as a delicate instrument as accurate function is critical to process safety. It is important to drive carefully and smoothly when transporting PSVs. • PSVs returned or taken to the field, will be transported and handled using the same degree of care and attention. • After removal, PSVs shall be transported upright and suitably supported to prevent rough handling to the PSV Shop. Flange faces shall be protected to prevent damage. • PSVs shall be stored away from heavy materials to prevent mechanical damage. Rough handling can change the pressure setting which could result in an inaccurate “As Found” pop test result.
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6.6.5 PSV Identification and Shop Practice • On receipt of the PSV and relevant MWO, the technician will verify that the identification tag complete with equipment number has been applied by Maintenance Planning. Work will not start on the PSV without the MWO and equipment number. 6.6.5.1
New PSVs
• E&C shall provide the relevant documents and coordinate with Maintenance Planning per 6.3 (PSV Maintenance Planning Requirements for New Installations). 6.6.5.2
PSVs removed from Service or Storage
• The PSV must be accompanied by the equipment number tag and the relevant MWO before work begins. • A Pop test is required after the PSV has been removed from service or storage at the end of the maintenance cycle. Test results shall be recorded in the PSV Shop Log Book. The Test Report will be completed, attached to the MWO, and returned to Maintenance Planning. 6.6.5.3
Batch PSVs
• The Batch list will be created by Maintenance Planning. • The Batch number and quantity of PSVs shall be entered in the PSV Shop Log Book. • The Batch list shall be kept with the PSV Shop Log Book and can be used to track individual PSVs. • Field Operations shall record the equipment number and the Functional Location of Batch PSVs where removed and installed. This record shall be given to Maintenance Planning in a timely manner. 6.6.5.4
For PSVs removed and replaced with a spare An MWO is created for a PSV requiring PM. In this case, the existing PSV in service shall be replaced with an available spare. The MWO shall be used to record both the movement of the spare PSV into the existing 13
Functional Location and the Inspection and Testing of the PSV removed from service.
The PSV shop Technician shall add a “PSV Service Record” to the MWO document. The “PSV Service record shall show which PSV was removed for PM and which was installed into the existing location.
The MWO operations will identify when the SAP information is updated to show the movement of the spare PSV and identify the PM’ed PSV as a ready to go spare.
6.6.5.5
PSV’s on Nexen Owned Mobile Equipment
• The Department which owns the mobile equipment is responsible to take the equipment and PSV Specification Sheet to the Maintenance Department to get the PSVs PM’ed as required by Nexen’s PSV Program. • When such a PSV is brought to Maintenance Planning for “first time”, it will be treated as a new PSV per 6.3 (PSV Maintenance Planning requirements for New Installations). 6.6.6 PSV Inspection and Testing Three specific types of Inspection and Testing occurs for PSVs;
Pop Test – incoming test to verify SCE performance standard or pretest before installation. Inspection and Testing – PSV Overhaul and recalibration with final testing. Visual on-stream inspection – non intrusive and performed by the PSV owner.
6.6.6.1
Determining "As Found" Pop Pressure
• This is carried out to determine the “As Found” relieving pressure the PSV. This is the actual relieving pressure that would have occurred in the Functional Location while in operation. These pop test results shall be used to classify and record to the Pressure Relief Valve Inspection / Test Sheet the “As Found” condition as Pass, Fail/Fix, or Fail”.
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• The correct medium must be used during testing i.e. water for PSVs in liquid service, air for PSVs in gas service. • If the PSV lifts at or within +3 / -10% of the set pressure, the condition is Pass. • If the PSV lifts outside the tolerance of +3 / -10%, the condition may either be Fail/Fix, or Fail. The testing pressure may be increased to a maximum of 120% of the set pressure. • If the PSV fails to lift at 120% of the set pressure, does not hold pressure, or must be replaced due to extensive damage or corrosion, the condition is Fail. • If the PSV lifts outside the +3 / -10 % but below 120% and holds pressure the condition is Fail/Fix. 6.6.6.2 Actual PSV Inspection and Testing 6.6.6.2.1 Shop Visual Inspection • An external inspection is carried out to determine the condition of the PSV from its PM per 6.6.6.1. The results shall be recorded for future reference. 6.6.6.2.2 Dismantling of PSV • All PSV’s are dismantled, cleaned, and inspected except small “disposable” PSVs, i.e. Kingston Valve, Mat’l # 279540. These PSVs cannot be overhauled. They can only be retested. If found acceptable, they are retained for reuse, i.e. keep as spare. If they do not pass the calibration testing, they shall be scrapped. 6.6.6.2.3 Cleaning and Inspection of Parts • The individual components / parts of the Pressure Relief/Safety valve will be cleaned and inspected. • All components / parts found out of tolerance or specification shall be restored as permitted by the OEM or replaced with new. • All new parts fitted will be in accordance with the OEM specifications. 15
6.6.6.2.4 Reassembly of PSV • After inspection and cleaning the PSV will be assembled and tested. 6.6.6.2.5 Calibration / Final Testing
Testing requirements shall be as defined on the Pressure Relief Valve Inspection / Test Sheet.
Three test shall be performed to record the lifting and reset pressures. The lift pressure of each test must be within +/- 3% of the set pressure. Test results shall be record to the Pressure Relief Valve Inspection / Test Sheet.
One leakage test shall be performed as defined on and recorded to the Pressure Relief Valve Inspection / Test Sheet when practical. Leak test shall not be performed on small “disposable” PSVs.
A PSV Test and Date tag shall be attached to the PSV after final testing.
6.6.6.2.6 PSV Test and Date Tag • The Test and Date tag shall be attached to the PSV by the PSV Shop Technician after final Inspection and Testing are completed. • If the PSV is pop tested after 28 days, the PSV shall not be re-tagged. However, the pop test shall be recorded to the Pressure Relief Valve Inspection / Test Sheet in the MWO. The existing Test Date tag shall remain in place until the PSV is again Inspected and Tested. • The PSV Test and Date tag shall reference in the following order; Start of the Maintenance Plan/Cycle = Date of final Inspection and testing as Day-MonthYear; e.g. 09-09-11 or 09-SEPT-09 o Maintenance Plan/Cycle; e.g. 4Y = 4 year. o Set pressure; e.g. 75 PSI o
The complete information will look like; e.g. 16
9.9.11
2Y 75 PSI or
09 SEPT 11 2Y 75 PSI • The technician is responsible to advise the tag Test Date to Maintenance Planning within 24 hours of placing this tag on the PSV. The Test Date is the reference start time for the Maintenance Plan/Cycle to become ACTIVE. • The Test Date tag is to be removed only after the In-coming (at the end of the MP or when failed in service/storage) Pop Test is completed. The technician is to inform Maintenance Planning of the Date when the tag was removed to INACTIVE the Maintenance Plan/Cycle. 6.6.7 PSV Storage 6.6.7.1 An inventory of overhauled PSVs is available in the PSV shop. Each of the spare PSVs is tagged with the SAP Equipment Number and Test and Date. 6.6.7.2 The storage life for a spare PSV is defined by the cycle time in the Maintenance Plan. The PSV may be used up until the end of cycle time regardless if the valve has been in service or left in storage. At the end of the cycle time, the PSV must undergo Inspection and Testing. Following conditions apply: 6.6.7.2.1 If the PSV is to be kept in the PSV shop or any other storage location, the PSV shall have this functional location defined on the Maintenance Plan. The technician and or owner of the valve is to confirm this to Maintenance Planning. 6.6.7.2.2 PSVs not immediately used, have up to and including 28 days after date of Inspection and Overhaul (Test and Date tag) before they must be again pop tested once. 6.6.7.2.3 The PSV Test and Date cannot be post dated. This shall be the same date as the Inspection and Test. CAUTION! Before any PSV or Spare PSV is returned to service a visual inspection to verify cleanliness of visible internal component shall be completed. If the PSV has not been used within 28 days from the date of the Date tag, the PSV must be pop tested one time. 17
6.7
Training Only trained personnel will be authorized to work on Nexen Yemen Pressure Safety PSVs.
7.
Refresher training for technicians shall be provided every two years. A qualified third party company shall be contracted to administer this training. The training shall incorporate all references to this procedure and the API standards mentioned. Training records shall be maintained by the Maintenance Training Coordinator.
DOCUMENTATION / RECORDS KEEPING 7.1
E&C is responsible for ensuring that the PSV is designed to perform the required function. E&C will prepare the Purchase Requisition and ensure any ordered PSV will have spare parts and all the necessary technical documents.
7.2
Original PSV documentation will be filed and controlled in the E&C Document Control Library.
7.3
For each PSV in Nexen Yemen service, a complete, permanent record shall be kept by the Maintenance Department. The record of each device should include its specification data and historical records of Inspection and Test results (This will include CDTP if applicable, and service medium).
7.4
After inspection PSV will be installed at a specific location. The identification data of this location should be such that it matches the P&ID engineering requirement of that location.
7.5
A “PSV LOG BOOK” will be maintained by the PSV Test Shop to record testing. This log book is an additional reference which will not substitute the whole record keeping process.
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8.
ATTACHMENTS via Hyperlink Attachment 1:
Typical PSV Specification Sheet
Attachment 2:
Pressure Relief Valve Inspection and Test Sheet
Revision Date
Effective Date
Issued Date
October 12th, 2011
October 27, 2011
October 27, 2011
Prepared By: Document Type:
Adel Al-Saudi, Peter Wilkinson, Graham Chambers, Ralf Luthe Engineering Specifications
Master Holder:
E&C Manager
Description of Changes Version 3 to Version 4; Oct 12, 2011; R Luthe 1. 2. 3. 4. 5. 6. 7. 8.
Changed requirement to activate Maintenance Plan on date of Overhaul. Added requirement to POP test the PSV if held in storage for longer than 28 days. Added reference to PSV Practice Changed the Performance standard for incoming POP test from +10/-10% of set pressure to +3/-10% of set pressure. Identified the SCE Object List for Pass, Fail-Fix and Fail Added description for TEST and DATE tag and how these are to be completed. Identified process for On-Stream inspection Identified use of disposable PSVs and related testing methods.
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