Location of Pig traps in a Petrochemical plan/refinery

[muralimithun]

Have a query regarding safe location of pig traps for feedstock pipelines - Pipeline Size range 4" to 28" (All ASME codes - B31.4,B31.8 and B31.12). Plant fence to process units distance is approx 1.5 to 2km.
1.Should the Pig traps be located near plant fence and after the code break, run the piping on sleepers/pipe rack to different units.
2.Or the Pig traps be located inside individual process units (buried pipeline). Disadvantages are wider ROW required inside the utility corridor and spacing required form foundations of other pipe racks etc.
3. Above ground pipeline after it enters plant fence to be laid on sleepers and pipe racks with pig traps at process units. Challenges involve running the pipeline inside plant area on sleepers/pipe racks with vertical expansion loops due to space limitation.
Is there any code requirement/HSE requirement or Recommended practice for the same.

 

[1503-44]

Read section 1.0 SCOPE of the pipeline codes. Pig Launchers and recivers, as all piping related to pipeline facilities must be built outside of any refinery, B31.4 and .8 do not apply to any piping located inside any facility not directly related to TRANSPORTATION of oil or gas by pipeline. They do not even apply to piping located in a tank farm, as tanks do not perform any transportation function. Code breaks can only occur at points where the piping is not involved with transportation. A pipeline crossing a fence is still involved with transportation, thus remains B31.4/8 code pipeline. B 4 & 8 Piping includes pig launchers/receivers, control valves, relief valves, block valves, vents, drains and all piping and other devices that can affect the flow, the pressure, the temperature, or operation of the pipeline in any manner. So, the only place you can locate pipeline pipe is "outside the fence" of any other type of facility.

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[LittleInch]

The only issue really is what direction the pig traps point. There is a specific risk, though very low probability, of a pig or sphere shooting out of the barrel like an artillery shell. Many places either put the pig traps say 100 to 150m away or point then into an area where the are no bits of plant.

But otherwise its up to you. Balance the advantages of each.

As its your plant you could reduce the ROW to say 2m from the edge of the pipes. Just make sure you show the location of the buried pipes well.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

Pig traps are usually located far away from the downstream process plant, and the emergency shutdown valve upstream / downstream of the pig trap is a key safety component to mitigate loss of containment incidents occurring at the pig trap and limit the impact of explosions here at the plant. Speak to technical safety engineers also.

 

[GD2]

Muralimithun,

Usually the pig receiver in a facility will be at offsite location away from traffic as Littleinch pointed out.

GDD
Canada

 

[muralimithun]

Thank you all for the responses.