01 June 2013

Trapping Pigs

With the natural gas activity in our area, the term "trapping a pig" takes on a different meaning. We have two natural gas gathering pipelines intersecting on our property  and part of the routine pipeline maintenance involves sending a "pig" through the pipeline to push out condensate (water, sludge and other liguids). The pig is inserted into the pipeline via a "pig launcher" at a valve assembly and the pressure of the gas flow moves the pig along a section of the pipeline until it reaches a "pig trap". The arrival of the pig is signaled by a red pop-up disk on the trap.

Natural gas continues to flow through the pipeline after the pig is caught in the trap. The pig is removed from the trap by opening/closing valves to force the natural gas to by-pass the trap. With the valve to the pig trap closed, a vent valve is opened to reduce the gas pressure (1,100 PSI) in the trap.


Once the gas pressure in the trap is released, a door on the trap can be opened and the pig(s) removed.


1 comment:

Anonymous said...

Bob - Hello from Singapore - Great Blog. Could I ask you to possibly email me at hmainwaring@mondiale.com Would be much appreciated.

I'd like to ask you a few questions if I may.

Kindest regards.

Hugh Mainwaring