Butterfly Valve

general specifications of the butterfly valves

A butterfly valve is composed of valve body, soft seat or hard seat, disc, stem, packing, notched position plate, and a lever or gear. The seat is under compression when it is mounted in the valve body, thus making a seal around the periphery of the disc both upper and lower points where the stem passes through the seat. Packing is provided forming a positive seal around the stem for added protection in case the seal formed by the seat could become damaged. All the components cooperate to make the butterfly valve function at its best state.

manufacturing of the butterfly valves

Butterfly valve is available to be driven by the electric or the pneumatic actuator. It means that the entire equipment consists of the butterfly valve and the actuator. The electric butterfly valve and pneumatic butterfly valve differ at the different driving actuator. Since the resources of the power vary, these two types still have some common points.

Generally speaking, these two kinds of the butterfly valve adopt the unique principle of “floating airproof”. The principle is well appreciated because it can avoid the inner leak and reduce the friction resistance of the sealed valve seat and the moment of torsion. Therefore, it is widely used for cut-off and regulation in the systems of water supply, sewage treatment and neutral liquids in the mining industry, enterprises and high buildings.

The suitable medium and temperature for the specified butterfly valve are determined by the manufacturing materials and elaborately designed structures. The common materials are like the cast iron, ductile iron and carbon steel. Whatever, each point related to the manufacturing of the electric butterfly valve or the pneumatic butterfly valve should be complied with the according standards or regulations.

Complying with the principle of “floating airproof”, the electric butterfly valve and the pneumatic butterfly valve are popular for some appreciated advantages. The good reliability has been perfectly guaranteed. The floating valve seat can automatically find the best sealing position of valve plate in order to reach the better sealing effect and reduce the moment of torsion. Then, the used single-eccentric structure can reduce the abrasion of valve seat in the course of opening and closing and prolong the useful life. Besides, the global sealing surface can ensure the valve is sealed and doesn't leak, while closing, even if the valve doesn't fully close. And the unique design of pin can ensure the tight junction of the valve plate with the valve stem and it can be replaced. What else, the finish of heat-spraying epoxy resin monolithic coating can effectively prevent from rusting. It can be suitable for the different medium, only after you replace the material of the sealed valve seat.