Blinding guideline

Operations Supervision

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  Implement and enforce proper blinding procedures.
  
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  Be thoroughly familiar with their equipment and proper blinding procedures.
  
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  Approve deviations to blinding guideline.
  
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  Assist Reliability Inspectors in scheduling the inspection of “permanently” installed blinds.
  
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  For shutdowns, turnarounds, and confined space entries of vessels:
  

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  Prepare necessary blind lists with marked drawings or an adequate description of location.
  

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  Be thoroughly familiar with equipment and proper blinding guidelines.
  

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  Prepare equipment for installation of blinds, including using proper lockout/tagout procedures for appropriate valves upstream and downstream of the blind insertion location.
  
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  Issue safe work permits, specifying proper PPE for blind insertion.
  
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  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.
  

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  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.
  
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  Assure that blinds are spidered and gasketed, when needed, on the correct side.
  
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  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).
  
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  Sign the blind list when blinds are installed and removed.
  

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  Ensure that this SHG and Maintenance Craft Blinding Procedures are followed.
  

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  Obtain safe work permits from operating personnel prior to blinding vessels or lines.
  
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  Inspect blinds for size, flange rating, condition and material of construction prior to installation.
  
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  Install blinds according to prescribed craft procedures or standard industry practice.
  
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  Sign the blind list when blinds are installed and removed.
  

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  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.
  

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  Follow refinery guidelines for installation of blinds in flare lines or blowdown systems. See Section 6.3 of this guideline.
  

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  Develop and implement a written plan to periodically inspect “permanently” installed blinds.
  

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  All vessel drain piping which is connected or sufficiently near in-service process sewer systems will be either blinded or physically disconnected before entry permits are issued.
  

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  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.
  

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  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.
  

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  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.
  
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  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.
  
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  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.
  
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  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.
  

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  When the tube or shell side of an exchanger is to be opened to the atmosphere during operation of the unit, the lines to the tube or shell sides, except cooling water lines shall be blinded.
  

Lines

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  When hot work is to be performed on a line, the section involved will be blinded from connecting equipment (i.e., pumps, furnaces, towers, exchangers, other lines, etc.) and made hydrocarbon free.
  
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  Lines that have contained hazardous chemicals or hydrocarbons shall be safely prepared prior to blinding.
  
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  Refer to refinery Hot Tap Guidelines when performing hot taps or in-service welding.
  
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  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

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  If hot work is to be performed.
  
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  When block valves are leaking.
  
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  If the functional location of the pump is unattended by maintenance for more than 8 hours.
  

Compressors

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  When compressors are opened, blind the process lines if they are under pressure or if hot work is to be performed.
  

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  Before tanks are opened for entry, all hydrocarbon, chemical and steam lines connected directly to the tank must be blinded.
  

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  Foam lines connected to tank roof drain lines shall be blinded.
  

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  Prior to blind list approval, maintenance and operations supervision will identify all blind and energy source isolation locations.
  

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  Operations supervision will furnish maintenance planning with an approved blind list and marked P&IDs, drawings or adequate descriptions of locations.
  

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  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.
  

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  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.
  

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  The master copy of the blind list and the marked P&IDs must remain in the control room.
  

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  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.
  

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  The flange will be in accordance with the piping into which the blind will be installed.
  

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  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.
  
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  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.
  
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  Thinner blinds than recommended by Attachment V may be used for isolation-only applications.
  

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  Company or contractor craftsman will obtain the required permits after energy source control has been achieved per refinery safe work permit procedures.
  
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  Company or contractor craftsman will then begin installation of approved blinds.
  
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  Blinds are to be installed at the nearest accessible flange, consistent with safety and practicality, of any equipment to be isolated.
  

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  After blinds are installed, company or contractor craftsman will initial the master blind list for each blind they installed.
  
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  Red tags shall be attached to each blind after installation by operations personnel. The corresponding yellow tag will be posted in the control room.
  
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  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.
  

Blind Removal

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  Upon completion of work requiring blinds, company or contractor craftsman will obtain the required permit for removal of blinds.
  
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  When blinds are removed new gaskets will be installed.
  
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  Company or contractor Craftsman will remove blinds, then initial the master blind list.
  
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  Operations will visually check each blind for removal and initial the master blind list upon completion.
  
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  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.
  

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  Before work is started, a meeting will be held between Operations and Maintenance supervision to verify the following:
  

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  All sources of gas to the flare have been identified.
  
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  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.
  
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  Operations of the units connecting to the flare line have been reviewed to anticipate potential problems; production rates will be adjusted as necessary.
  
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  A work platform, where possible, with proper access and egress shall be provided.
  

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  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.
  
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  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.
  

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  Any deviations must be discussed and agreed to at a work planning meeting between Operations, Maintenance and Safety supervision. Refer to Section 6.4.
  

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  Clean or repair in place.
  

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

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  Pulling basket and immediately replacing it.
  

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

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

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  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.
  
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  Changing out pressure gauges
  
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  Working on valved instrument taps
  
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  Working on utility air systems, utility water below 140 degrees F