What Are The Structural Features Of Lined Ball Valve?

With the continuous development of industry, the demand for Lined Ball Valve, especially those for high-temperature, high-pressure, and harsh operating conditions, is increasing. Ball valves are required to exhibit higher resistance to wear, erosion, high temperature, and corrosion. Traditional full-bore ball valves, while featuring surface hardening treatments such as cladding and spray coating, still fall short of the service life, cost, and performance requirements for demanding applications such as industrial silicon, coal chemical industry, blast furnace gas, and natural gas. The double-eccentric semi-ball valve is a new product developed by integrating the advantages of various ball valves, V-shaped ball valves, and orbital ball valves. The double-eccentric semi-ball valve utilizes a double-eccentric sealing structure, resulting in low wear, low torque, excellent sealing performance, and long service life. The valve seat and semi-ball body are treated with a special hardening process, specifically designed to withstand the harsh demands of wear, erosion, corrosion, and high temperature. The double-eccentric semi-ball valve has the following key structural features:
1. The semi-ball body of the double-eccentric semi-ball valve utilizes a double-eccentric design, providing reliable sealing, instant release, low torque, and long service life. It can be used in demanding applications such as conveying granular media. Its structural principle is that the centerline of the hemisphere is offset from the centerline of the valve stem and the centerline of the valve seat. When fully open, the sphere and seat are completely disengaged, with a certain clearance. The turning radius is divided into a long radius and a short radius. The tangent of the long radius rotation trajectory forms an angle θ with the valve seat sealing surface. During valve opening and closing, the hemisphere gradually disengages and engages the seat surface, reducing mechanical wear and scratches between the seat and hemisphere during opening and closing, thereby increasing service life.

2. The valve seat adopts a floating design to reduce machining complexity and ensure that the centerline of the valve seat coincides with the center point of the hemisphere's spherical surface, thereby improving sealing performance. There is a gap between the valve seat and the valve body. During assembly, the hemisphere automatically locates the centerline, ensuring full contact between the valve seat sealing surface and the hemisphere. This eliminates leakage caused by machining precision errors and improves the performance and life of the ball valve. The seal between the valve seat and the valve body utilizes a hard seal structure, suitable for high-temperature and high-pressure operating conditions. The sealing contact surface dimension c between the valve seat and the valve body is small, and high precision is required for each sealing surface. During assembly, the retainer is installed using an electric impact wrench. This not only ensures the retainer engages with the valve body to prevent loosening, but also frictionally rotates the valve seat, conforming to the principle of mechanical vibration engagement, ensuring a reliable seal between the valve seat and the valve body. A two-point hard seal is employed between the valve seat and the valve body, and between the valve seat and the hemisphere, making this valve suitable for high-temperature and high-pressure operating conditions.

3. The double-eccentric hemisphere valve adopts an overall modular design, resulting in a simple structure, high reliability, and high versatility. The valve stem utilizes a blowout prevention structure. A variety of actuation methods are available. The connection dimensions of the valve stem, bracket, and actuator comply with ISO5211, allowing direct integration with various standard actuators. Common actuation methods include manual, pneumatic, hydraulic, gas-hydraulic, and electric, enhancing the performance of double-eccentric hemispheric valves.