The standard control valve seat leakage rating control valve is an important part of flow and pressure control valves in pipelines and equipment. There are not only single seat, double seat, sleeve and other stop valve types of control valves, but also angle stroke automatic pneumatic ball valve and automatic butterfly valve for use with control valves. This type of control valve has a stronger flow capacity. The leakage level of the leakage valve of the control valve is an important performance parameter for acceptance of the use of the control valve. There are many misunderstandings about the definition and application of the leakage level of the control valve seat, which affect the correct selection of the control valve.

With the application of chemical resistant synthetic rubber in butterfly valves, the performance of butterfly valves has been improved. Because synthetic rubber has the characteristics of corrosion resistance, erosion resistance, stable size, good resilience, easy forming and low cost, and can choose synthetic rubber with different properties according to different use requirements to meet the operating conditions of butterfly valves, it is widely used to manufacture lining and elastic seat of butterfly valves.