A patent certificate (ZL201610246292.6) for the invention of Involute Butterfly Control Valve was issued by the Chinese State Patent Office on January 2, 2018. 

The design of Involute Butterfly Control Valves adopts the mechanism of involute trajectory double crank slider, which allows the control stem bears no other forces except the force from crank stem. And this is an excellent solution of the pervasive bending and distorting problems of existing pipe valves, and what's more, this enables valves to be made with shorter face to face dimensions. 

With brilliant performance of under-loading pump start, water hammer annihilating, preventing back flow and automatic control, Involute Butterfly Control Valves is a upgraded equipment of existing pipe valves, is a very good valve-choice for outlet of centrifugal pump. It is reported that the Involute Butterfly Control Valves has gone into production recently. 

Browse our website to know more about our vavles: http://www.dervosvalve.com/valves.html