Pigging in pipeline is a process in pipeline maintenance that involves the use of devices known as pigs, which clean pipelines and are capable of checking pipeline condition without necessarily stopping or interfering with the flow of product in the pipeline.
The primary purpose of pipeline pigs is to make sure that the pipe is clean and free from obstruction. The pig is usually cylindrical or spherical to aid movement and efficient cleaning. As the pig moves through the pipeline, it can possibly detect and remove any build-ups within the pipe which can often lead to reduced performance, increased energy costs and cause corrosion, which could lead to disastrous leaks and cracks in the pipeline.
Pipeline pigging is used in number of industries including oil & gas, lube oil, chemical plants and hygienic applications such as pharmaceutical or food.