Top mounted design: The valve body is cast or forged as a whole, effectively ensuring the compactness of the pressure bearing parts. The sphere is installed from the upper end of the valve body, making it easy to disassemble and maintain online, reducing downtime and maintenance costs.
Valve cover extension design: Strictly control the gap between the valve stem and the extended neck, reduce cold flow upward, and prevent the increase of switch torque and valve stem scratches caused by packing icing. The design of the outer circular long neck annular lunar groove increases the cooling dissipation area and enhances the cooling dissipation effect.
Valve seat structure: Adopting an adjustable spring preloaded valve seat design, the valve seat is pushed towards the sphere under the action of spring and medium pressure, ensuring sealing performance under low temperature and low pressure. Some products use imported PCTFE and other materials for the valve seat sealing surface, which still has good elasticity under ultra-low temperature conditions, ensuring that the seal does not fail.
Valve stem sealing: A lip shaped sealing ring is used to form a primary seal, and then a compressed valve stem packing is used to form a secondary seal. Some products also adopt a self centering design for the pressure cover and pressure sleeve, effectively preventing imbalance caused by uneven force on the pressure cover.
Material: Stainless Steel, Alloy Steel
Nominal Size: NPS 1/2"~24", DN 15~600
Pressure Rate: Class 150~2500, PN 10~420
Temperature Range: -196°C~+150°C
Operator: Manual, Pneumatic, Electric, etc...
Application Range: LNG, LPG, LNG low temperature conditions and long-distance pipelines such as oil, gas, and natural gas.
The working principle of the three eccentric butterfly valve is based on its unique structural design, which achieves sealing and flow control functions through three eccentric distances: Structural Design: Three Eccentric Structure: The valve stem axis deviates from the center of the butterfly plate and the body center, and the rotation axis of the valve seat is at an angle to the axis of the valve body channel. This design enables the butterfly plate to form a wedge-shaped space with the valve seat when closed, achieving sealing through friction. Conical Sealing Surface: The periphery of the butterfly plate is machined into an external inclined conical surface, and the valve seat is an internal inclined conical surface, forming an elliptical contact surface. When closed, the butterfly plate achieves sealing through the asymmetric pressing force in the up and down directions, and the sealing becomes tighter as the pressure increases. Working Mechanism: Open State: The butterfly plate is separated from the valve seat, and the fluid passes through the channel; due to the eccentric design, during the opening process, the butterfly plate gradually detaches from the valve seat, reducing friction and operating torque. Closed State: The butterfly plate rotates 90° to contact the valve seat, forming a wedge-shaped space and achieving sealing through torque. Flow Regulation: During the opening rotation of the butterfly plate, the valve's flow area gradually increases, reducing fluid resistance and improving the flow coefficient, achieving flow regulation. Technical Advantages: Sealing Performance: The metal-to-metal hard sealing method can still maintain good sealing performance in high-temperature and high-pressure environments; Low Friction Operation: The eccentric design significantly reduces the operating torque and extends the valve's lifespan; Self-Locking Function: When closed, the butterfly plate becomes tighter under pressure, preventing the phenomenon of over-positioning. This valve is widely used in the petroleum, chemical, and power industries, and common structural connection forms include double flange type, welding type, lug type, and socket type, etc.
The structure adopts a short pattern, the valve gate is light in weight, and the pipe support frame can be saved. Diversified Drive Modes: Electric, gearbox, hydraulic and pneumaticcan be selected at will. High performance sealing combination packing: The combined packing sealing system isadopted to greatly improve its sealing performance.
The quality of forged steel parts is higher than that of cast steel parts, and they can withstand the impact of beatings. The plasticity, toughness, and other mechanical properties are higher than those of cast steel parts. The diameter of cast steel gate valves is generally not more than DN80, and most of them are reduced-diameter designs. Compared with cast steel gate valves of the same diameter, the flow rate is slightly lower, but the pressure and temperature range they can withstand are higher than those of cast steel valves, and the sealing performance is much better than that of cast steel gate valves, and the service life is longer. The flow direction of the medium is not restricted like other gate valves.