Ball valve is a kind of valves using the ball as closing part, which mainly consist of valve body, valve seat, valve ball, valve stem and handle (or other actuating device).
Driven by the stem, the ball valve rotates around its axis. In the pipeline, it is mainly used to do cut off, distribute, and change the flow direction of medium. For there are many different kinds of ball valves, including different principle and medium as well as the application, the user should choose different types of ball valve on the basis of corresponding requirements. Ball valve is classified according to actual working condition.
According to the structural form, ball valve can be divided into:
1. Floating ball valve
The ball is floating. Under the effect of medium pressure, the ball will will do certain displacement and compression on the seal surface of outlet to ensure the outlet sealing.
Floating ball valve has simple structure and good sealing, but all the medium pressure will transfer to the sealing face of outlet. Therefore, people should consider whether the seal material can withstand medium working load of ball. This structure is widely used in middle & low pressure ball valve.
2. Trunnion mounted ball valve
The ball is fixed. Trunnion mounted ball valve won’t do movement after compression. In that it has floating seat, under the medium pressure, the valve seat will move to compress the sealing ring on the ball, ensuring sealing performance. In general, there will be bearings on top shaft and bottom shaft, so the operating torque is small. This kind of structure is suitable for high pressure and large diameter valves.
In order to reduce the operating torque and increase the sealing availability, the oil sealing ball valve emerged in recent years. This kind of ball valve not only strengthened the sealing performance, but also reduced the operating torque. It is more suitable for high pressure and large diameter valves.
3. Elastic Ball Valve
The ball is elastic. Due to the ball and sealing ring of seat are made from metal materials, its sealing pressure is very large. It has to exert external forces because the medium pressure can’t meet the sealing requirements. This kind of ball valve is suitable for high temperature and high pressure medium.
The principle is opening a elastic groove in external ball to get elasticity. Before rotating the ball, people should loose the sphenocephaly and let the ball restore the original shape. In this way, there will be a narrow gap which can reduce the friction and operating torque of sealing surface.
In addition, common classification of ball valve has the following kinds:
According to the pressure rating: high pressure ball valve, medium pressure ball valve, low pressure ball valve.
According to the flow channel: full size ball valve, reducing valve.
According to the channel position: cut-through ball valve, three way ball valve, right angle ball valve.
According to the temperature: high temperature ball valve, room temperature ball valve, low temperature ball valve, cryogenic ball valve.
According to the sealing form: soft seal ball valve, hard seal ball valve.
According to the valve stem assembly: jacket type ball valve, side mounted ball valve.
According to the connection: flanged ball valve, welding ball valve, threaded ball valve, clamping ball valve.
According to the drive mode: manual ball valve, automatic control valves, electric ball valves, hydraulic ball valve.
According to the diameter size: ultra large diameter, large diameter valves, middle-size diameter ball valve, small diameter ball valve.
Driven by the stem, the ball valve rotates around its axis. In the pipeline, it is mainly used to do cut off, distribute, and change the flow direction of medium. For there are many different kinds of ball valves, including different principle and medium as well as the application, the user should choose different types of ball valve on the basis of corresponding requirements. Ball valve is classified according to actual working condition.
According to the structural form, ball valve can be divided into:
1. Floating ball valve
The ball is floating. Under the effect of medium pressure, the ball will will do certain displacement and compression on the seal surface of outlet to ensure the outlet sealing.
Floating ball valve has simple structure and good sealing, but all the medium pressure will transfer to the sealing face of outlet. Therefore, people should consider whether the seal material can withstand medium working load of ball. This structure is widely used in middle & low pressure ball valve.
2. Trunnion mounted ball valve
The ball is fixed. Trunnion mounted ball valve won’t do movement after compression. In that it has floating seat, under the medium pressure, the valve seat will move to compress the sealing ring on the ball, ensuring sealing performance. In general, there will be bearings on top shaft and bottom shaft, so the operating torque is small. This kind of structure is suitable for high pressure and large diameter valves.
In order to reduce the operating torque and increase the sealing availability, the oil sealing ball valve emerged in recent years. This kind of ball valve not only strengthened the sealing performance, but also reduced the operating torque. It is more suitable for high pressure and large diameter valves.
3. Elastic Ball Valve
The ball is elastic. Due to the ball and sealing ring of seat are made from metal materials, its sealing pressure is very large. It has to exert external forces because the medium pressure can’t meet the sealing requirements. This kind of ball valve is suitable for high temperature and high pressure medium.
The principle is opening a elastic groove in external ball to get elasticity. Before rotating the ball, people should loose the sphenocephaly and let the ball restore the original shape. In this way, there will be a narrow gap which can reduce the friction and operating torque of sealing surface.
In addition, common classification of ball valve has the following kinds:
According to the pressure rating: high pressure ball valve, medium pressure ball valve, low pressure ball valve.
According to the flow channel: full size ball valve, reducing valve.
According to the channel position: cut-through ball valve, three way ball valve, right angle ball valve.
According to the temperature: high temperature ball valve, room temperature ball valve, low temperature ball valve, cryogenic ball valve.
According to the sealing form: soft seal ball valve, hard seal ball valve.
According to the valve stem assembly: jacket type ball valve, side mounted ball valve.
According to the connection: flanged ball valve, welding ball valve, threaded ball valve, clamping ball valve.
According to the drive mode: manual ball valve, automatic control valves, electric ball valves, hydraulic ball valve.
According to the diameter size: ultra large diameter, large diameter valves, middle-size diameter ball valve, small diameter ball valve.
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