Pigging refers to maintenance practice for pipelines using ‘pipeline pigs’, for cleaning or inspection of pipeline without stopping operation of the pipeline. Pipeline pigs are capsule shaped objects which travel through the pipeline, cleaning the inner walls of the pipeline by brushing action. Pigs get their name from the squealing sound they make while traveling through a pipeline.
source.image: Eng Pi π
These operations include but are not limited to cleaning and inspecting the pipeline. This is accomplished by inserting the pig into a “pig launcher” (or “launching station”)—an oversized section in the pipeline, reducing to the normal diameter.
The launching station is then closed and the pressure-driven flow of the product in the pipeline is used to push the pig along the pipe until it reaches the receiving trap—the “pig catcher” (or “receiving station”).
Advertisement
Pigging requires the pipeline to be designed to be pigged from the outset. If the pipeline contains topological variations including changes in diameter, butterfly valves, instrumentation, tight bends, pumps or reduced port ball valves, the pipeline cannot be traditionally pigged.
