Blinding and Isolation

VALERO – KROTZ SPRINGS

SHG #6 Page 1 of 13 Revised 01/14/04 BLINDING GUIDELINE

1.0

PURPOSE This guideline specifies vessel and line blinding methods to be used within this facility by employees and contractors.

2.0

SCOPE This guideline applies to all Valero and contractor employees involved in blinding within this facility.

3.0

DEFINITIONS • • • • •

• 4.0

Blinding - The absolute seal off of a pipe, duct, vessel, exchanger, tower or other refinery equipment using a properly designed metal plate inserted between two flanges or bolted onto the end of a flanged pipe and vessel. Blind List - A written record listing where blinds have been or must be inserted to isolate specific pieces of equipment. This guide or list includes the location, size and flange rating of each blind to be installed. Slip Blind Spacer ("Spidering") - A space created between a blind and the equipment being blinded by insertion of appropriately designed spacers to allow draining or venting during flushing, steam-out, etc. Blind Tags - weatherproof, red and yellow tags which are numbered in pairs that are used to identify the location and size of blinds installed. (See Attachment IV) Blind Book - the master record book in which blinding is recorded. This book contains the blind tag numbers, a description of the blind, its location, the blind size, date installed, operator responsible for installation, date removed, and operator responsible for removal. This book will remain in the Control Room/Pumpers Office at all times and will be kept for a minimum of two years after the last entry (See Attachment III) Permanently Installed Blinds - Blinds intended to remain installed and in service indefinitely. These will appear on P&I Diagrams.

POLICIES 4.1

General Blinding Policies/Exceptions

•

Process equipment to be cleaned, inspected, repaired or tested is typically isolated from other refinery equipment by the use of blinds. Closing single block valves is usually not sufficient, even with lockout.


SHG #6 Page 2 of 13 Revised 01/14/04

•

Vessels are normally blinded at the first flange. If blinding at the first flange poses more hazard to the personnel involved than blinding at a second or alternate flange, the first flange practice can be waived but only with operations supervision approval. With this approval, the blind can then be installed in the next accessible piping flange. This alternate blind location can only be used if there is a bleeder on the vessel side or if blind spacers are installed to allow the line to be gas tested prior to issuing entry or hot work permits.

•

The requirements of SHG #11 Lock, Tag and Try must be followed when installing blinds and working on equipment that has been blinded.

•

Blinding exceptions may be made where it is more hazardous to install blinds than to perform work or where locked and chained double block valves and bleeders are present which allow verification of isolation. Specific exceptions must be approved by agreement of operations and maintenance supervision.

•

For situations where flanges are not available or appropriate such as tubing or threaded pipe, capping or plugging shall be used for isolation.

4.2

Labeling of Blinds • • •

4.3

Blinds to be used must be stenciled with size, flange rating and thickness. Blinds manufactured in-house shall be stenciled before use. When purchasing new blinds they shall be stenciled with proper size, flange rating and thickness prior to shipment. When a blind is removed from service confirm proper size, flange rating and thickness and stencil if needed before reinstalling.

Installation of Blinds in Uncleared Lines/Vessels Normally, blinds will be installed in lines that have been emptied, purged and/or washed. However, the practice of installing blinds with hydrocarbons or other refinery products in the lines can be allowed. Each installation in an uncleared line or vessel will be reviewed by the operations and maintenance/contractor supervision coordinating the work. A safe procedure to install these blinds, including the personal protective equipment required, will be agreed on before the work is allowed to start. Generally, this equipment will be maintained under a slight positive pressure to prevent influx of air into the process system. If the system must be maintained at a slight positive pressure (with nitrogen, steam, etc.), this condition will be noted in the blank space following "Other" in Section B, Checklist, of the safe work permit issued for the work.


5.0


RESPONSIBILITIES

Responsible Group/Individual Operations Supervision • • • • •

Operations Personnel

•

• • • • Maintenance/ Contractor • Supervision Maintenance/ Contractor • Personnel • • •

• Reliability Inspectors

•

Responsibilities Implement and enforce proper blinding procedures. Be thoroughly familiar with their equipment and proper blinding procedures. Approve deviations to blinding guideline. Assist Reliability Inspectors in scheduling the inspection of “permanently” installed blinds. For shutdowns, turnarounds, and confined space entries of vessels:  Prepare necessary blind lists with marked drawings or an adequate description of location. Be thoroughly familiar with equipment and proper blinding guidelines.  Prepare equipment for installation of blinds, including using proper lockout/tagout procedures for appropriate valves upstream and downstream of the blind insertion location.  Issue safe work permits, specifying proper PPE for blind insertion.  Inform appropriate maintenance or contractor supervision of any special hazards involved and the precautions to be taken, especially to identify equipment/lines containing toxic gases or means used to maintain equipment under slight positive pressure. Identify location where blinds need to be installed or removed based on blind lists. Locations of blinds for running maintenance activities will be jointly identified with maintenance/contractor personnel. Assure that blinds are spidered and gasketed, when needed, on the correct side. Field verify against equipment blind lists or drawings that blinds and gaskets of the proper size and flange rating are installed in the proper location(s). Sign the blind list when blinds are installed and removed. Ensure that this SHG and Maintenance Craft Blinding Procedures are followed. Obtain safe work permits from operating personnel prior to blinding vessels or lines. Inspect blinds for size, flange rating, condition and material of construction prior to installation. Install blinds according to prescribed craft procedures or standard industry practice. Sign the blind list when blinds are installed and removed.  Before opening any flanged joint for the installation of a blind refer to SHG #57, Safe Line Breaking Guideline. Flanges should be left open a minimum length of time consistent with the safe installation of the blind. Follow refinery guidelines for installation of blinds in flare lines or blowdown systems. See Section 6.3 of this guideline. Develop and implement a written plan to periodically inspect “permanently” installed blinds.


6.0


REQUIREMENTS

6.1 Blinding Guidelines By Type of Service Equipment Type Blinding Requirements Reactors, Towers & General • All vessel drain piping which is connected or sufficiently near in-service Drums process sewer systems will be either blinded or physically disconnected before entry permits are issued. • For gauge glasses, displacers, sight glasses, bridles and other chemical or oil bearing traps, blinding will be required if evidence of thorough steam-out and water wash is not present. Caps should be removed, low point bleed valves should be wide open and free flowing, and steam-out/purge connections should be disconnected or blinded before entry or hot work permits are issued. Entry and Hot Work • When towers and drums are opened for entry or out-of-service hot work, blind all lines except sight glasses, pressure gauge, liquid level columns, trycocks or connecting lines that have been removed or disconnected prior to entry. Relief valves venting to a closed system need to be blinded. Relief valves venting to atmosphere need not be blinded. Furnaces/ Boilers • For ID tube cleaning, repairs in firebox, including hot work or any activity that will risk the integrity of the tubes, the charge lines, transfer line or lines, blowdown lines, fire box steam, fuel gas, burner steam out lines, flare lines and pilot gas lines shall be blinded. • For routine jobs in firebox, i.e. fire brick or refractory repair, ultrasonic testing the tubes, etc. fuel gas, pilot gas and the firebox steam shall be blinded. • Whenever the burner and pilot fires are out in a furnace or boiler, for an extended period of time, the fuel gas lines to the burners must be blinded. Fuel gas line blinds will be removed only when the furnace is ready to be fired. • When working in a furnace fire box which has a common stack with another furnace in service, some means to blind or isolate the flue gas duct must be provided. • When the tube or shell side of an exchanger is to be opened to the Exchangers atmosphere during operation of the unit, the lines to the tube or shell sides, except cooling water lines shall be blinded. NOTE - An exchanger may be required to be blinded on both sides if there is a potential of a leaking tube that would allow hydrocarbon or chemical leakage. • When hot work is to be performed on a line, the section involved will be Lines blinded from connecting equipment (i.e., pumps, furnaces, towers, (Out of Service) exchangers, other lines, etc.) and made hydrocarbon free. • Lines that have contained hazardous chemicals or hydrocarbons shall be safely prepared prior to blinding. • Refer to refinery Hot Tap Guidelines when performing hot taps or in-service welding. • Blinding may not be necessary for fire water and potable water lines if it can be confirmed by operations that the line has been adequately secured by block valves and proper lockout/tagout.


Pumps

• • •

Compressors • Tanks

• •


If hot work is to be performed. When block valves are leaking. If the functional location of the pump is unattended by maintenance for more than 8 hours. When compressors are opened, blind the process lines if they are under pressure or if hot work is to be performed. Before tanks are opened for entry, all hydrocarbon, chemical and steam lines connected directly to the tank must be blinded. Foam lines connected to tank roof drain lines shall be blinded.

6.2 Blinding Guidelines Blinding Steps Action List/Responsibilities Blind List/Location • Prior to blind list approval, maintenance and operations supervision will identify all blind and energy source isolation locations. Identification • Operations supervision will furnish maintenance planning with an approved blind list and marked P&IDs, drawings or adequate descriptions of locations. • The approved blind list and marked P&IDs, drawings or adequate descriptions of locations, can then be issued by maintenance planning. A master copy will be supplied to appropriate control rooms. • For priority 1 and 2 work orders, maintenance planning may not be furnished an approved blind list. Maintenance and operations supervision will field identify all blind and energy source isolation locations. Follow record keeping per section 7. • The master copy of the blind list and the marked P&IDs must remain in the control room. • Any changes required in the blind list must be approved by operations supervision. The changes must be noted and initialed on the master blind list by the person approving the changes. • The flange will be in accordance with the piping into which the blind will be Blind Selection installed.  Blind thickness shall be determined according to the maximum pressure & temperature the blind must contain. Blinds which must contain pressure may be selected according to Attachment V.  Note Attachment V is only applicable to blinds in ambient temperature service. Thicknesses for blinds which may encounter temperature higher than 700 degrees must be recommended by Inspection personnel.  Thinner blinds than recommended by Attachment V may be used for isolation-only applications.


Blinding Steps


Action List/Responsibilities • Company or contractor craftsman will obtain the required permits after Blind Installation energy source control has been achieved per refinery safe work permit procedures. • Company or contractor craftsman will then begin installation of approved blinds. • Blinds are to be installed at the nearest accessible flange, consistent with safety and practicality, of any equipment to be isolated. NOTE: OPERATORS MUST ENSURE THAT ALL BLINDS ARE INSTALLED IN THE CORRECT LOCATION AND THAT LINES OR EQUIPMENT UNDER PRESSURE, OR THOSE CONTAINING HYDROCARBONS, ARE NOT INADVERTENTLY OPENED DURING INSTALLATION OF BLINDS. • After blinds are installed, company or contractor craftsman will initial the master blind list for each blind they installed. • Red tags shall be attached to each blind after installation by operations personnel. The corresponding yellow tag will be posted in the control room. • Upon completion by craftsmen, an operations supervisor or his designee will visually check each blind and verify installation. This representative will then initial the master blind list for each blind they installed. • Upon completion of work requiring blinds, company or contractor craftsman Blind Removal will obtain the required permit for removal of blinds. • When blinds are removed new gaskets will be installed. • Company or contractor Craftsman will remove blinds, then initial the master blind list. • Operations will visually check each blind for removal and initial the master blind list upon completion. • After craftsmen and operations have completed blind removal and initialed the master blind list documenting visual verification, operations supervision or their designee will visually check that all blinds have been removed and remove any blind location identifiers. After verification that all blinds have been removed, an operations supervisor or their designee will initial the master blind list as complete.


6.3 Notes:


Opening of Flare Lines While in Service (1)

Any invasive work involving active flare systems requires the use of fresh air. CONTRACTOR PERSONNEL SHALL NOT INSTALL BLINDS IN ACTIVE FLARE LINES UNLESS VALERO SUPERVISION IS PRESENT AND DIRECTING THE WORK AT THE BLINDING SITE.

(2)

Type of Action •

Precautions

• • •

Deviations

Precautions Before work is started, a meeting will be held between Operations and Maintenance supervision to verify the following:  All sources of gas to the flare have been identified.  A communications system is established so that there is direct contact between the workers at the site and any unit that could release gas into the flare.  Operations of the units connecting to the flare line have been reviewed to anticipate potential problems; production rates will be adjusted as necessary.  A work platform, where possible, with proper access and egress shall be provided. During the work, Operations will be present to monitor the progress of the work and to assure communications with affected units is maintained. A fire watch with a charged fire hose line will also be standing by during this work. Craftsmen performing the work will use supplied air respirators and clothing suitable for flash fire protection. Flash fire protective clothing (bunker pants, coat, gloves & Nomex hood) meeting NFPA 600 requirements will be worn. Any deviations must be discussed and agreed to at a work planning meeting between Operations, Maintenance and Safety supervision. Refer to Section 6.4.

6.4

Blinding Deviations

•

All deviations from these guidelines must be discussed and approved by Operations, Maintenance and Safety supervision before the job begins.

•

Deviations can be considered by Maintenance and Operations supervision if they agree on the following points:  

The hazard involved in blinding for the jobs is greater than performing the work. Any leakage could be managed safely.


•


Deviations may also be considered by Maintenance and Operations supervision if all of the following apply:      

The temperature of the material is < 140 oF The process pressure of the material is < 40 psig The vapor pressure of the material is < atmospheric pressure (14.7 psia) The product temperature is below the flash point The material is not considered toxic The material is not considered corrosive

All deviations from blinding except those situations listed in Attachment I (Approved Blinding Deviations) shall be documented using the "Blinding Deviation Form", Attachment II, by the Unit Superintendent or Shift Supervisor and the Maintenance Supervisor. The Operations, Maintenance, and Safety department heads will determine which deviations will require system modifications. Attachment I (Approved Blinding Deviations) cannot be modified without approval by the Plant Director. 7.0

Recordkeeping Records of multiple blind installations must be kept to verify that all appropriate blinds have been installed or removed. These records must contain the following information as a minimum: • • • • •

•

Blind tag number Equipment/system identification Blind size and description Date installed and removed Identification of the operations, maintenance (or contractor) personnel who verifies installation and/or removal of blinds Identification of operations person who verifies that the final blind removal is complete.


SHG #6 Page 9 of 13 Revised 01/14/04 ATTACHMENT I

THE FOLLOWING IS A LIST OF APPROVED BLINDING DEVIATIONS THAT ARE VALID IF PROPER ENERGY SOURCE CONTROL PROCEDURES ARE FOLLOWED . EQUIPMENT MAINTENANCE ACTIVITY/TYPE OF SERVICE Level Column/Sight Glass •

Clean or repair in place.

Control/Relief/Check/Block • /Valves •

Repack/work in place without exposing process to the atmosphere. Removing a valve and immediately replacing it with a new or different valve.

Strainers

•

Pulling basket and immediately replacing it.

Turbines

• • • • •

Governor work Replace sentinel valve/bleeder/utility piping Inlet strainer cleaning Bearing replacing where split lines are not separated Overspeed trip assembly removal and immediate replacement

Compressor

• • •

Non process side work Utility air services Repairing or replacing utility piping

General

•

Closed, locked, block valves on both sides of an open bleeder afford protection equivalent to a blind if proper energy source control (lockout/tagout) procedures are followed. Changing out pressure gauges Working on valved instrument taps Working on utility air systems, utility water below 140 degrees F

• • •


SHG #6 Page 10 of 13 Revised 01/14/04 ATTACHMENT II BLINDING DEVIATION FORM

DATE:_______________ TIME:________________ DESCRIPTION OF EQUIPMENT & SERVICE: ____________________________________________________________________________ ____________________________________________________________________________ ____________________________________________________________________________ REASON FOR THE BLINDING DEVIATION: ____________________________________________________________________________ ____________________________________________________________________________ ____________________________________________________________________________ DO YOU RECOMMEND THIS AS BEING AN ACCEPTABLE LONG TERM PRACTICE? YES  NO  IF NO, SUGGESTION FOR ELIMINATING THE NEED TO DEVIATE: ____________________________________________________________________________ ____________________________________________________________________________ ____________________________________________________________________________ IF YES, SHOULD THIS TYPE OF DEVIATION BE ADDED TO THE LIST OF APPROVED BLINDING DEVIATIONS? YES  NO 

____________________________ UNIT/AREA SUPERINTENDENT Route To:

Operations Director Maintenance Director Safety Manager

_________________________________ MAINTENANCE SUPERVISOR


SHG #6 Page 11 of 14 Revised 01/14/04 ATTACHMENT III MASTER BLIND LIST

Blind Tag #

Description / Location

Size

Date In

Initial In OPS

Maint

Date Out

Initial Out OPS

Maint

OPS


SHG #6 Page 12 of 14 Revised 01/14/04 ATTACHMENT IV BLINDING TAGS

YELLOW

Ο No.

5127

RED

Ο No.

5127

FIRST OPERATION

FIRST OPERATION

________________________________

________________________________

Operation ________________________

Operation ________________________

Line Size ________________________

Line Size ________________________

Location _________________________

Location _________________________

________________________________

________________________________

Work Done By ____________________

Work Done By ____________________

a.m.

a.m.

Date __________ Time _________p.m.

Date __________ Time _________p.m.

BLIND TAG

BLIND TAG


SHG #6 Page 13 of 13 Revised 01/14/04 ATTACHMENT V BLIND THICKNESS SELECTION TABLE Maximum temperature 700 degrees Consult Reliability Inspectors for applications hotter than 700 degrees

Pressure (PSIG) 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 1200 1250

1/2" ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼

3/4" ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼

1" ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼

1 1/2" ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375

2" ¼ ¼ ¼ ¼ ¼ ¼ ¼ ¼ 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 0.375 ½ ½

3" ¼ ¼ ¼ ¼ 0.375 0.375 0.375 0.375 0.375 0.375 0.375 ½ ½ ½ ½ ½ ½ ½ ½ ½ ½ ½ 0.625 0.625 0.625

4" ¼ ¼ 0.375 0.375 0.375 0.375 0.375 ½ ½ ½ ½ ½ ½ ½ 0.625 0.625 0.625 0.625 0.625 0.625 0.625 0.625 0.625 ¾ ¾

Nominal 6" ¼ 0.375 0.375 ½ ½ ½ 0.625 0.625 0.625 0.625 0.625 ¾ ¾ ¾ ¾ ¾ 0.875 0.875 0.875 0.875 0.875 0.875 0.875 1 1

Pipe Size 8" 10" 0.375 0.375 0.375 ½ ½ 0.625 ½ 0.625 0.625 ¾ 0.625 ¾ ¾ 0.875 ¾ 0.875 ¾ 0.875 ¾ 1 0.875 1 0.875 1 0.875 1.125 0.875 1.125 1 1.125 1 1.125 1 1¼ 1 1¼ 1.125 1¼ 1.125 1¼ 1.125 1.375 1.125 1.375 1.125 1.375 1.125 1.375 1¼ 1½

12" 0.375 0.625 0.625 ¾ 0.875 0.875 1 1 1.125 1.125 1.125 1¼ 1¼ 1¼ 1.375 1.375 1.375 1½ 1½ 1½ 1.625 1.625 1.625 1.625 1¾

14" ½ 0.625 ¾ ¾ 0.875 1 1 1.125 1.125 1¼ 1¼ 1¼ 1.375 1.375 1½ 1½ 1½ 1.625 1.625 1.625 1¾ 1¾ 1¾ 1¾ 1.875

16" ½ 0.625 ¾ 0.875 1 1.125 1.125 1¼ 1¼ 1.375 1.375 1½ 1½ 1.625 1.625 1.625 1¾ 1¾ 1.875 1.875 1.875 2 2 2 2.125

18" ½ ¾ 0.875 1 1.125 1¼ 1¼ 1.375 1½ 1½ 1.625 1.625 1¾ 1¾ 1.875 1.875 1.875 2 2 2.125 2.125 2.125 2¼ 2¼ 2.375

20" 0.625 ¾ 1 1.125 1¼ 1¼ 1.375 1½ 1.625 1.625 1¾ 1¾ 1.875 2 2 2.125 2.125 2.125 2¼ 2¼ 2.375 2.375 2½ 2½ 2½

24" ¾ 1 1.125 1¼ 1.375 1½ 1.625 1¾ 1.875 2 2 2.125 2¼ 2¼ 2.375 2½ 2½ 2.625 2.625 2¾ 2¾ 2.875 2.875 3 3

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