How it Works
 
Pigging works by propelling a device with wiping discs (the Pig) through the pipeline from the source to the destination. As the pig travels through the pipeline, it pushes out the trapped product and cleans the pipe walls leaving the pipeline ready for the next product transfer. The pig is most frequently propelled with air or nitrogen, but can be just as effectively be pushed with a liquid such as a cleaning or flush media or even another product. Typically any liquid, resin, or paste product that can be pumped can also be pigged.