Physical cleaning of pneumatic conveying pipe internals is difficult due to the enclosed nature and relative inaccessibility of the pipe. Removing the pipe and cleaning off-line is possible but very time and labor intensive. Cleaning pipes in place is generally done using a projectile called a “pig” that scours the pipe wall as it travels. The video demonstrates how a pigging system operates.
![](https://i.ytimg.com/vi/b2howfRSvQE/maxresdefault.jpg)