http://www.sinomachflange.com/valve/check-valve/ Check Valve for sale Multifunctional slow closing check valve is a multifunctional (slow-closing) check valve with power unit and air travel coupler, and electric/manual valve opening, valve closing, and short-time throttling; the valve seat is inclined, all-metal sealing pair, butterfly .The plate is double-biased, the overcurrent element is equipped with a guide body and an oil pressure slow closing device, which can be divided into: fast/slow two-stage valve closing. This product is a new type of multi-functional anti-hammer energy-saving product. It can be widely used in petrochem