Working principle of pneumatic butterfly valve The butterfly plate is driven by the valve stem. If it turns 90 °, it can be opened and closed once. The flow of medium can be controlled by changing the deflection angle of the butterfly plate. The commonly used butterfly valves are wafer type butterfly valve and flange type butterfly valve. Wafer type butterfly valve uses stud bolts to connect the valve between two pipe flanges. Flange type butterfly valve has flanges on the valve, and bolts are used to connect the flanges on both ends of the valve to the pipe flanges.

The joints of pneumatic butterfly valves are various
As we know, as an important connection equipment in modern engineering equipment, the connection is naturally essential. Next, let's introduce some connectors.
NPT, PT, G are pipe threads
NPT is the abbreviation of National (American) Pipe Thread, and NPT is the American taper pipe thread used for sealing. The 60 degree taper pipe thread belongs to the American specification, and is used in North America. National specifications can be referred to GB/T12716-1991PT is the abbreviation of Pipe Thread, which is a 55 degree sealed taper pipe thread. It belongs to Wyeth thread family, and is mostly used in Europe and the Commonwealth countries. It is commonly used in water and gas pipe industries, and the taper rule is 1:16. National specifications can refer to GB/T7306-2000G, which is a 55 degree non thread sealing pipe thread and belongs to Wyeth thread family. G represents cylindrical thread. Refer to GB/T7307-2001 for national specifications. G is the general name of pipe thread (Guan). 55 and 60 degrees are functional, commonly known as pipe circle. That is, the thread is machined from a cylindrical surface.
Metric threads are represented by pitch, and American and British threads are represented by the number of threads per inch, which is the biggest difference between them.
Metric thread is 60 degree equilateral thread, inch thread is 55 degree isosceles thread, and American thread is 60 degree.
Metric units are used for metric threads, and English units are used for American and British threads.