Pipeline Pig

Part of the routine maintenance of natural gas pipelines is to remove water, scale and rust from the pipeline using a device called a "pig". The pipeline operations crew was on our property this week to "launch a pig" in the 24 inch gathering pipeline.

To launch a pig, the reddish cylindrical object in the left of the photo, they need to close valves and bleed off the 900 PSI gas pressure in the launcher section. When the bleed valves are opened, as shown in the photo, it sounds like a jet engine at takeoff.



Once the excess pressure in the launch section is removed, the access door can be opened and the pipeline pig inserted. After the pig is positioned in the launch section, the door is closed/latched and valves opened to pressurize the launch section and push the pig downstream in the pipeline. As the pig is pushed through the pipeline it will form sealed plug in the pipeline and push the water ahead of it to the next valve in the pipeline where the pig and water is trapped and removed.