First, the H74 on the folder univalve Swing Check Valve Overview 

 Product Name: H74 on the folder univalve Swing Check Valve 
 Category: Check Valve 
 Material: WCB, CF3, CF8, CF3M, CF8M 
 Product specifications: DN50 ~ 1200, PN10 ~ 40 
 Features: Disc shut down quickly, the water hammer pressure is small; horizontal pipe or vertical pipe can be used, easy installation; smooth flow channel. 
 Small fluid resistance; short stroke of the valve, the impact of small off valve; long service life and reliability of high-impedance