There are significant differences between eccentric hemispherical valves and fixed ball valves in terms of structural design, sealing performance, application scenarios, and operational characteristics. The following is a specific comparative analysis of the two:

1、 Structural Design

1. Eccentric hemispherical valve:

The eccentric hemisphere valve adopts an eccentric design, and there is an eccentricity between the valve shaft and the centerline of the hemisphere. This design ensures that the contact between the ball core and the valve seat only exists at the moment of closing and opening the valve, thereby reducing the wear of the valve core and valve seat.

The spherical surface of an eccentric hemispherical valve usually does not have a V-shaped port, and its sealing surface design focuses on achieving tight cutting.

2. Fixed ball valve:

The ball of a fixed ball valve is supported and fixed by upper and lower valve stems, and can only rotate without horizontal movement. It usually has a floating valve seat, which moves under the pressure of the medium, causing the sealing ring to press tightly against the sphere to ensure sealing.

The spherical structure of a fixed ball valve is relatively simple, but its sealing performance is stable and reliable, making it suitable for high-pressure and large-diameter applications.

2、 Sealing performance

1. Eccentric hemispherical valve:

The eccentric hemispherical valve has excellent sealing performance, especially in working conditions that require tight shut-off. Its eccentric design allows the ball core to tightly fit the valve seat when closed, achieving zero leakage.

The eccentric hemispherical valve also has a self-cleaning function. When the ball tilts away from the valve seat, the fluid in the pipeline passes uniformly along the sealing surface of the ball in a 360 ° angle, washing away the accumulated material on the sealing surface and helping to maintain the cleanliness and sealing performance of the sealing surface.

2. Fixed ball valve:

The sealing performance of fixed ball valves is also reliable, and their floating seat design can adapt to changes in medium pressure, maintaining a tight fit between the sealing ring and the ball.

Fixed ball valves usually have bidirectional sealing function, which means that regardless of whether the valve is fully open or fully closed, the upstream and downstream valve seats can block the fluid, improving the safety and reliability of the valve.

3、 Application scenarios

1. Eccentric hemispherical valve:

Eccentric hemispherical valves are widely used in working conditions that require tight shut-off, such as petroleum, chemical, and urban water supply and drainage. Its unique eccentric design and self-cleaning function make it perform well in handling media containing impurities such as fibers and particles.

Eccentric hemispherical valves are also suitable for sewage treatment, pulp, alumina, urban heating and other applications, as well as for controlling power plants, hydraulic slag removal, or gas transmission pipelines.

2. Fixed ball valve:

Fixed ball valves are suitable for long-distance pipelines and general industrial pipelines, especially performing well in high-pressure and large-diameter situations. Its strength, safety, and resistance to harsh environments have been specially considered in the design, and it is suitable for various corrosive and non corrosive media.

Fixed ball valves are also widely used in fields such as petroleum refining, chemical engineering, papermaking, pharmaceuticals, water conservancy, electricity, municipal engineering, and steel.

4、 Operational characteristics

1. Eccentric hemispherical valve:

The eccentric hemispherical valve has a small opening and closing torque and is easy to operate. Its eccentric design reduces the friction between the ball core and the valve seat during rotation, reducing operational difficulty and energy consumption.

The eccentric hemispherical valve also has a cutting function, which can cut off impurities in the medium when closed, ensuring the normal opening and closing of the valve.

2. Fixed ball valve:

The operation of a fixed ball valve is also effortless, as its ball is supported by upper and lower bearings, reducing friction and torque.

Fixed ball valves are usually equipped with advanced actuators and control devices, which can achieve remote control and automated operation.