Briefly describe the classification and structure of ball valves
Ball valves are divided into: floating ball valve, fixed ball valve, orbital ball valve, V-shaped ball valve, three-way ball valve, stainless steel ball valve, cast steel ball valve, forged steel ball valve, ash discharge ball valve, anti-sulfur ball valve, pneumatic ball valve, electric ball valve, ferrule ball valve, Welded ball valve.
According to the shell/body material classification, ball valves can be divided into:
1. Metal material valve: such as carbon steel valve, alloy steel valve, stainless steel valve, cast iron valve, titanium alloy valve, Monel valve, copper alloy valve
Doors, aluminum alloy valves, lead alloy valves, etc.
2. Metal valve body lining valves: such as rubber-lined valves, fluorine-lined valves, lead-lined valves, plastic-lined valves, and enamel-lined valves.
3. Non-metallic material valves: such as ceramic valves, glass valves, plastic valves.
There are many domestic manufacturers of ball valves, and most of the connection sizes are not uniform. Mainly divided into the following categories:
The ball of the ball valve is floating. Under the action of medium pressure, the sphere can produce a certain displacement and press tightly on the sealing surface of the outlet end to ensure the sealing of the outlet end.
The structure of the ball valve:
The sealing performance is good, but the load of the sphere carrying the working medium is all transferred to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the spherical medium. When impacted by higher pressures, the spheres may deflect. This structure is generally used for medium and low pressure ball valves.
The ball of the ball valve is fixed and does not move after being pressed. Fixed ball valves have floating seats. The valve seat will move after being subjected to the pressure of the medium, so that the sealing ring is tightly pressed on the sphere to ensure the sealing. Bearings are usually installed on the upper and lower shafts of the sphere, with small operating torque, suitable for high-pressure large-diameter valves.
In order to reduce the operating torque of the ball valve and increase the reliability of the seal, the oil-sealed ball valve appears, which not only injects a special lubricant between the sealing surfaces to form an oil film, enhances the sealing performance and reduces the operating torque. Suitable for high pressure and large diameter ball valves.