Pillow Type Plug Mean?
A pillow type plug is used to temporarily block or divert product flow in a pipe. These types of plugs are also used to aid in the process of pressure testing. They are made of heavy duty elastic rubber and normally reinforced with Kevlar or other materials. Once they have been put into position, they are inflated in place. A pillow type plug is an essential component of trenchless rehabilitation and repair processes.
Trenchlesspedia Explains Pillow Type Plug
A pillow type plug is able to plug nearly all types of pipe profiles and materials. Pillow type plugs are inflated by an above ground compressor with inert gas or water once they have been put into place in the pipe. For some applications, when the coefficient of friction is not enough to hold the pillow type plug in place, it may need to be mechanically supported. Additionally, it may also need to be retrieved down stream after use.