H664Y series extraction check valve
Valve type: swing typeExtraction check valve
Caliber range: DN100-DN1000
Pressure range: PN16-PN100, ANSI 150-ANSI600
Temperature range: -29-+560 ℃
Leakage level: ANSI B16.104 VI
Main body materials: WCB, WC6, WC9
Drive device: pneumatic, hydraulic check valve

A check valve refers to a type of valve whose opening and closing components are circular valve discs that act by their own weight and medium pressure to block medium backflow. It belongs to the category of automatic valves, also known as check valves, one-way valves, return valves or isolation valves. The valve disc movement can be divided into lifting and rotating types. Lift check valves have a similar structure to globe valves, except for the lack of a valve stem that drives the valve disc. The medium flows in from the inlet end (lower side) and flows out from the outlet end (upper side). When the inlet pressure exceeds the sum of the weight of the valve disc and its flow resistance, the valve is opened. On the contrary, when the medium flows back, the valve closes. A swing check valve has a valve disc that is inclined and can rotate around an axis, and its working principle is similar to that of a lift check valve. Check valves are commonly used as bottom valves in pumping devices to prevent water from flowing back. The combination of check valve and globe valve can achieve safety isolation. The disadvantage is high resistance and poor sealing when closed.