Definition - What does Polly Foam mean?
Polly foam pigging is a type of trenchless inspection and rehabilitation method used in pipelines. These pigs are open cell polyurethane foam type and can be used for sealing and to lightly remove abrasion. Pigs were primarily used for cleaning out a pipeline, but now pigs can be equipped with a computerized inspection probe to make it an intelligent pig which can also carry testing devices.
Trenchlesspedia explains Polly Foam
Polly foam pigs can navigate short bends, ells, tees, miter bends and port valves, and come in different densities depending on their application and requirement. These pigs are the least aggressive of the three pigs, i.e. steel mandrel, unibody pig and polly foam pig. Because of their flexibility, these pigs can reduce in diameter up to 35%. It can also be attached with nose pull rope, transmitter cavity and wire strip brushes to increase their functional requirements.
Pigging and robotic inspection have become an important part of trenchless operations. These methods have made it easier to inspect new pipelines for commissioning, and for inspecting old pipelines for damage before selecting a trenchless rehabilitation method.