Forged Steel Bellows Seal Globe Valve

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.

This series of products features a compact structure, small size, and S-shaped fluid channels. The valve core adopts a pressure-balancing structure, with high accuracy of the flow characteristic curve and the ability to achieve a larger CV. It can be quickly replaced, is stable and reliable, and is easy to maintain. A smaller actuating force can control a high pressure difference. There is a sealing ring between the valve core and the valve cage, significantly reducing the leakage. It is equipped with the RSMF series multi-spring pneumatic diaphragm actuator, which has a large thrust, strong steel strength, sensitive action, high-precision positioning, fast response, convenient and sturdy, and a long service life.

The “Double Block and Bleed Isolation Philosophy” requires two in-line isolation valves and a bleed valve, used to drain or vent trapped fluid between the two closure elements in order to safely isolate safely the downstream pipe. This feature can be achieved with one single valves c/w a bleed port between the obturators.