Butterfly check valve refers to a valve that automatically opens and closes the valve flap depending on the flow of the medium itself and is used to prevent the medium from flowing back. It is also called non-return valve, one-way valve, backflow valve, and back pressure valve.
 
Design feature
 
Butterfly check valves include swing check valves and lift check valves. Swing check valves have a hinge mechanism and a valve flap like a door that rests freely on an inclined valve seat surface. In order to ensure that the valve clack can reach the proper position of the valve seat surface every time, the valve clack is designed in the hinge mechanism so that the clack has enough swing space and contacts with the valve seat comprehensively. The valve clack can be made entirely of metal, or the metal inlaid with leather, rubber, or a synthetic covering, depending on the performance requirements. Besides, when the swing check valve is fully opened, the fluid pressure is almost unimpeded. Therefore, the pressure drop through the valve is relatively small.
 
The disc of the lift check valve is located on the sealing surface of the valve seat. Except that the valve disc can freely rise and fall, the rest of the valve is like a globe valve. The fluid pressure forces the valve disc to be lifted from the sealing surface of the valve seat, and the medium backflow causes the valve disc to fall back onto the valve seat and cut off the flow. On the basis of the use conditions, the valve clack can be of all-metal structure or can be inlaid with the structure of rubber pads or rubber rings on its frame. Like stop valves, the passage of fluid through the lift check valve is narrow. Thus, the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow rate of the swing check valve is rarely limited. Valves of this type shall be installed horizontally in pipelines.

Nortech is one of the leading industrial valve manufacturers in China with quality certification ISO9001.

Major products: Butterfly Valve, Ball Valve,Gate Valve, Check Valve, Globe Vavlve,Y-Strainers, Electric Acurator , Pneumatic Acurators .

 For more interest, welcom to contact  at: Email: sales@nortech-v.com