The butterfly valve is a valve that opens and closes according to the rotary valve, driving the disk plate to rotate. In the cylindrical channel of the butterfly body, the disc rotates around the axis, mainly rotating the plate 90 degrees.

A wafer check valve is a type of check valve used in pipelines to prevent the backflow of fluid. It is called a "wafer" check valve because of its wafer-like, thin de​sign, which allows it to fit between two pipeline flanges, typically without the need for additional gaskets or bolts. Here are the key features and functions of a wafer check valve: