Fixed ball valves are equipped with floating seats, under the pressure of the medium, the seat is moved, so that the sealing ring is firmly pressed on the ball to ensure the seal. Bearings are usually installed on the upper and lower shafts of the ball, and the operation 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, in recent years, the oil seal ball valve has appeared, both in the sealing surface pressure injection of special lubricating oil to form a layer of oil film, that is, to enhance the sealing, but also reduce the operating torque, more suitable for high-pressure large-caliber ball valves.

Fixed ball valve, flanged gate valve, flanged butterfly valve and oxygen pressure reducing valve are the same type of valve, the difference is that its closing part is a ball, the ball rotates around the center line of the valve body to achieve the opening and closing of a valve. Ball valves are mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. Ball valve is a new type of valve widely used in recent years.

advantage

1. The fluid resistance is small, and its resistance coefficient is equal to that of the pipe segment of the same length.

2. Simple structure, small size, light weight.

3. Tight and reliable, the sealing surface material of the ball valve is widely used in plastic, good sealing, and has also been widely used in vacuum systems.

4. Easy to operate, open and close quickly, from full open to full close as long as the rotation of 90 degrees, easy to remote control.

5. Easy maintenance, ball valve structure is simple, the sealing ring is generally active, disassembly and replacement are more convenient.

6. When fully open or fully closed, the sealing surface of the ball and the seat is isolated from the medium, and the medium will not cause erosion of the valve sealing surface when it passes through.

7. Wide range of application, small diameter to a few millimeters, large to a few meters, from high vacuum to high pressure can be applied. When the ball is rotated 90 degrees, the inlet and outlet should all be spherical, thus cutting off the flow.

Working principle

First, start the process

1. In the closed position, the ball is pressed against the seat by the [wiki] mechanical [/wiki] pressure of the valve stem.

2, when the counterclockwise rotation of the handwheel, the valve stem is in reverse motion, its bottom corner plane makes the ball out of the seat.

3, the valve stem continues to lift, and interact with the guide pin in the spiral groove of the valve stem, so that the ball begins to rotate without friction.

4. Until the full open position is reached, the valve stem is raised to the limit position, and the ball is rotated to the full open position.

2. Closing process

1, close, turn the hand wheel clockwise, the stem begins to drop and make the ball leave the seat and start to rotate.

2. Continue to rotate the handwheel, and the valve stem is acted by the guide pin embedded in its upper spiral groove, so that the valve stem and the ball rotate 90° at the same time.

3, about to close, the ball has been rotated 90° without contact with the seat.

4, the last few turns of the hand wheel rotation, the angular plane at the bottom of the valve stem is mechanically wedged to compress the ball, so that it is tightly pressed on the seat to achieve complete seal.

Fixed ball valves are equipped with floating seats, under the pressure of the medium, the seat is moved, so that the sealing ring is firmly pressed on the ball to ensure the seal. Bearings are usually installed on the upper and lower shafts of the ball, and the operation 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, in recent years, the oil seal ball valve has appeared, both in the sealing surface pressure injection of special lubricating oil to form a layer of oil film, that is, to enhance the sealing, but also reduce the operating torque, more suitable for high-pressure large-caliber ball valves.

Advantages:

1. The fluid resistance is small, and its resistance coefficient is equal to that of the pipe segment of the same length.

2. Simple structure, small size, light weight.

3. Tight and reliable, the sealing surface material of the ball valve is widely used in plastic, good sealing, and has been widely used in the vacuum system.

4. Easy to operate, open and close quickly, from full open to full close as long as the rotation of 90 degrees, easy to remote control.

5. Easy maintenance, ball valve structure is simple, the sealing ring is generally active, disassembly and replacement are more convenient.

6. When fully open or fully closed, the sealing surface of the ball and the seat is isolated from the medium, and the medium will not cause the erosion of the sealing surface of the valve.

7. Wide range of application, small diameter to a few millimeters, large to a few meters, from high vacuum to high pressure can be applied. When the ball is rotated 90 degrees, the inlet and outlet should all be spherical, thus cutting off the flow.

How it works:

First, start the process

1. In the closed position, the ball is pressed against the seat by the [wiki] mechanical [/wiki] pressure of the valve stem.

2. When the handwheel is turned counterclockwise, the valve stem moves in reverse, and its bottom angular plane makes the ball free from the seat.

3. The valve stem continues to lift and interact with the guide pin in the spiral groove of the valve stem so that the ball begins to rotate without friction.

4. Until it reaches the full open position, the valve stem is raised to the limit position, and the ball is rotated to the full open position.

2. Closing process

1. When closing, turn the handwheel clockwise, the stem begins to drop and the ball starts to rotate away from the seat.

2. Continue to rotate the handwheel, the valve stem is subjected to the action of the guide pin embedded in its upper spiral groove, so that the valve stem and the ball rotate 90° at the same time.

3. When close, the ball has rotated 90° without contact with the seat.

4. In the last few turns of the hand wheel rotation, the angular plane at the bottom of the valve stem is mechanically wedged to compress the ball, so that it is tightly pressed against the seat to achieve complete seal.

Structural features:

1. Frictionless opening and closing. This function completely solves the problem that the sealing of traditional valves is affected by the friction between the sealing surfaces.

2, top type structure. The valve installed on the pipeline can be directly checked and repaired online, which can effectively reduce the device parking and reduce the cost.

3, single seat design. The problem that the medium in the valve cavity is affected by abnormal pressure increase is eliminated.

4, low torque design. The stem with special structural design can be easily opened and closed with a small wheel valve.

5, wedge sealing structure. The valve is sealed by the mechanical force provided by the valve stem, and the ball wedge is pressed to the seat, so that the sealing of the valve is not affected by the change of the pressure difference of the pipeline, and the sealing performance is reliably guaranteed under various working conditions.

6. Self-cleaning structure of sealing surface. When the ball tilts away from the seat, the fluid in the pipeline passes 360° evenly along the sealing surface of the ball, which not only drives away the local erosion of the high-speed fluid on the seat, but also washes away the accumulation on the sealing surface to achieve the purpose of self-cleaning.