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:
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
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