Ball valve and plug valve are the same type of valve, only its closing part is a ball, the ball rotates around the center line of the valve body to open and close a valve.
The ball valve is mainly used in the pipeline to cut, distribute and change the flow direction of the medium. Ball valve is a new valve that has been widely used in recent years. It has the following advantages:
1. The fluid resistance is small, and its drag coefficient is equal to the length of the same length.
2. Simple structure, small size, light weight.
3. It is compact and reliable. At present, the sealing surface material of the ball valve is widely used with plastics and has good sealing performance. It has also been widely used in vacuum systems.
4. Easy to operate, fast opening and closing, as long as the rotation from 90 degrees from full open to fully closed, easy remote control.
5. Easy maintenance, ball valve structure is simple, the seal ring is generally active, removal and replacement are more convenient.
6. When fully open or fully closed, the sealing surfaces of the ball body and the valve seat are isolated from the medium. When the medium passes through, the sealing surface of the valve will not be eroded.
7. Wide range of applications, from small to several millimeters in diameter, up to a few meters in height, from high vacuum to high pressure can be applied.
Ball valve has been widely used in petroleum, chemical, power generation, paper, atomic energy, aviation, rockets and other departments, as well as people's daily lives.
Ball valve can be divided according to the structure:
One, floating ball valve
The ball of the ball valve is floating. Under the effect of medium pressure, the ball can generate a certain displacement and press on the sealing surface of the outlet end to ensure the sealing of the outlet end.
The structure of the floating ball valve is simple and the sealing is good. However, the load of the ball bearing the working medium is transmitted to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This structure is widely used in low and medium pressure ball valves.
Second, fixed ball valve
The sphere of the ball valve is fixed and does not move after being pressed. The fixed ball ball valve has a floating valve seat. After the medium pressure, the valve seat moves and the seal ring is pressed against the ball to ensure the seal. Bearings are usually mounted on the upper and lower shafts of the ball, and the operating torque is small, suitable for high pressure and large diameter valves.
In order to reduce the operating torque of the ball valve and increase the reliability of the seal, oil seal ball valves have appeared in recent years. Special lubricants are injected between the sealing surfaces to form a layer of oil film, which enhances the sealing performance and reduces the operating torque. , It is more suitable for high pressure and large diameter ball valve.
Third, the elastic ball valve
The sphere of the ball valve is elastic. The ball body and the valve seat seal ring are made of metal materials, and the specific pressure of the seal is large. The pressure of the medium itself cannot meet the requirements of the seal, and an external force must be applied. This valve is suitable for high temperature and high pressure media.
The elastic ball is to open a flexible groove at the lower end of the inner wall of the ball to obtain elasticity. When closing the channel, use the wedge head of the valve stem to make the ball expand and seal with the valve seat. Loosen the wedge head before turning the ball, the ball will return to its original shape, so that there is a small gap between the ball and the valve seat, which can reduce the friction and operating torque of the sealing surface.
Ball valve according to its position can be divided into straight-through, three-style and right angle. The latter two ball valves are used to distribute media and change media flow
The ball valve is mainly used in the pipeline to cut, distribute and change the flow direction of the medium. Ball valve is a new valve that has been widely used in recent years. It has the following advantages:
1. The fluid resistance is small, and its drag coefficient is equal to the length of the same length.
2. Simple structure, small size, light weight.
3. It is compact and reliable. At present, the sealing surface material of the ball valve is widely used with plastics and has good sealing performance. It has also been widely used in vacuum systems.
4. Easy to operate, fast opening and closing, as long as the rotation from 90 degrees from full open to fully closed, easy remote control.
5. Easy maintenance, ball valve structure is simple, the seal ring is generally active, removal and replacement are more convenient.
6. When fully open or fully closed, the sealing surfaces of the ball body and the valve seat are isolated from the medium. When the medium passes through, the sealing surface of the valve will not be eroded.
7. Wide range of applications, from small to several millimeters in diameter, up to a few meters in height, from high vacuum to high pressure can be applied.
Ball valve has been widely used in petroleum, chemical, power generation, paper, atomic energy, aviation, rockets and other departments, as well as people's daily lives.
Ball valve can be divided according to the structure:
One, floating ball valve
The ball of the ball valve is floating. Under the effect of medium pressure, the ball can generate a certain displacement and press on the sealing surface of the outlet end to ensure the sealing of the outlet end.
The structure of the floating ball valve is simple and the sealing is good. However, the load of the ball bearing the working medium is transmitted to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This structure is widely used in low and medium pressure ball valves.
Second, fixed ball valve
The sphere of the ball valve is fixed and does not move after being pressed. The fixed ball ball valve has a floating valve seat. After the medium pressure, the valve seat moves and the seal ring is pressed against the ball to ensure the seal. Bearings are usually mounted on the upper and lower shafts of the ball, and the operating torque is small, suitable for high pressure and large diameter valves.
In order to reduce the operating torque of the ball valve and increase the reliability of the seal, oil seal ball valves have appeared in recent years. Special lubricants are injected between the sealing surfaces to form a layer of oil film, which enhances the sealing performance and reduces the operating torque. , It is more suitable for high pressure and large diameter ball valve.
Third, the elastic ball valve
The sphere of the ball valve is elastic. The ball body and the valve seat seal ring are made of metal materials, and the specific pressure of the seal is large. The pressure of the medium itself cannot meet the requirements of the seal, and an external force must be applied. This valve is suitable for high temperature and high pressure media.
The elastic ball is to open a flexible groove at the lower end of the inner wall of the ball to obtain elasticity. When closing the channel, use the wedge head of the valve stem to make the ball expand and seal with the valve seat. Loosen the wedge head before turning the ball, the ball will return to its original shape, so that there is a small gap between the ball and the valve seat, which can reduce the friction and operating torque of the sealing surface.
Ball valve according to its position can be divided into straight-through, three-style and right angle. The latter two ball valves are used to distribute media and change media flow
EXA International Trading (Tianjin) Co., Ltd , http://www.tjsteelplank.com