Triangular eccentric butterfly valve

The three-bias butterfly valve is mainly used in industrial pipeline systems where high requirements are placed on sealing reliability and operational stability. It is suitable for applications with long-term operation, frequent opening and closing, or significant changes in working conditions. This type of valve adopts a three-dimensional bias metal sealing structure. During the opening and closing process, the butterfly plate moves along a preset spatial trajectory, and there is no sliding contact between it and the valve seat. This reduces the wear on the sealing surfaces from a structural perspective.
In actual operation, the butterfly plate only comes into contact with the valve seat at the final stage of complete valve closure. During the closing process, the butterfly plate gradually adheres to the metal valve seat to form a seal, rather than achieving the cutoff through instantaneous compression. This progressive sealing method has a relatively small impact on the sealing state after multiple openings and closings, which is beneficial for maintaining stable cutting performance of the valve over a long period of operation. This type of three-bias butterfly valve is mostly used in medium and large-sized pipeline systems. The common nominal diameters usually range from DN50 to DN600, corresponding to approximately 2″ to 24″ in imperial sizes. In terms of pressure ratings, it can be applied to the working conditions of Class 150 to Class 2500, meeting the usage requirements of conventional industrial pipelines as well as higher pressure systems.
The valve body material is usually selected based on the characteristics of the medium, working pressure and temperature conditions. Under normal operating conditions, A105, LF2 and other forged steel materials can be used; in applications requiring higher temperature or pressure resistance, F11, F22 and other alloy steels can be chosen; when the medium is corrosive or has requirements for material cleanliness, stainless steel or nickel-based alloys such as Hastelloy C-276 and Inconel 718 can also be used. The specific material configuration can be adjusted according to the project's operating conditions. This valve is generally connected by flange. The connection dimensions and standards can be carried out in accordance with common specifications such as ASME and EN, which is convenient for installing in conjunction with the existing pipeline system. In terms of operation mode, the small diameter specification can be operated manually; as the diameter increases, a gearbox is usually configured, and pneumatic or electric actuators can also be selected according to control requirements.
The applicable temperature range of the valve mainly depends on the combination of the valve body material and the metal sealing structure. By selecting the appropriate type, it can meet the usage requirements under different temperature conditions. In the industries such as petroleum, chemical engineering, power, metallurgy, and public works, this type of three eccentric butterfly valve is mostly used for the on-off or cut-off control of the medium. Due to the absence of continuous friction between the sealing surfaces during the opening and closing process, the valve experiences relatively less wear over a long period of operation, which helps to reduce the maintenance frequency and extend the overall service life.