Check valve and check valve, check valve, is a kind of used to prevent the reverse flow of medium in the pipeline, valve belong to automatic valve class, because when the pump stop running in, media will put back the clock, as if there is no check valve installation, will be in the reflow process middle water hammer effect, have damage on the pipes and pumps.

Check valve according to the structural form can be divided into the lift check valve, spiral type check valve, butterfly check valve, mute vertical check valve, check valve, slow close check valve, etc., lift check valve and rotary type check valves are generally flange connection, and butterfly check valve of the wafer, mostly vertical check valve is axial movement, slow close check valve using occasions, do not allow the check valve closure quickly, because that would make a big water hammer, the damage of equipment. Another silent check valve, and used in the pump at the bottom of the bottom valve, the basic functions are the same.

Check valves are commonly used materials such as cast iron, carbon steel, stainless steel, pressure range from 1.6 MPa to 25 MPa, applicable temperature from 550 ℃ to 40 ℃ to choose suitable non-return valve according to actual working condition.