Pneumatic two-piece ball valve | Two-piece pneumatic ball valve | The difference between two-piece and three-piece pneumatic ball valves:
One-piece ball valve, two-piece ball valve and three-piece ball valve are fundamentally different in valve body structure.
The one-piece ball valve is composed of a ball, a PTFE ring, and a lock nut. A plug head fixes the ball. It has a small size, reliable sealing, simple structure, and easy maintenance. One piece is reduced in diameter, the actual circulation diameter is smaller than the thread diameter.
The two-piece ball valve is fixed by clamping the ball with two pieces of valve body. The sealing effect is better than the one-piece ball valve. The maintenance is relatively complicated. The tightness of the bolt in the middle is critical, which is related to whether it leaks. Two-piece ball valves are not suitable for high pressure.
The three-piece ball valve is similar to the two-piece ball valve, but there is a valve body in the middle of the ball, which is then clamped by the flanges with necks on both sides. Unlike the two-piece ball valve and the one-piece ball valve, the three-piece ball valve is easy to disassemble and maintain.
Pneumatic two-piece ball valve | Two-piece pneumatic ball valve | The difference between two-piece and three-piece pneumatic ball valves:
The working principle of the one-piece ball valve, that is, the wide ball valve, is to rely on the rotary valve to make the valve unblocked or blocked. The ball valve switch is light and small, can be made into a large diameter, reliable sealing, simple structure, easy maintenance, the sealing surface and the spherical surface are often in a closed state, not easy to be eroded by the medium, and is widely used in various industries.
Two-piece ball valve 1. No friction when opening and closing. This function completely solves the problem that the traditional valve affects the sealing due to the friction between the sealing surfaces.
2. Top-mounted structure. The valve installed on the pipeline can be directly inspected and repaired online, which can effectively reduce the device shutdown and reduce the cost.
3. Single valve seat design. The problem that the medium in the valve cavity affects the safety of use due to abnormal pressure increase.
4. Low torque design. The valve stem with special structure design can be easily opened and closed with only a small handle.
5. Wedge seal structure. The valve relies on the mechanical force provided by the valve stem to press the ball wedge onto the valve seat to seal, so that the valve's tightness is not affected by the change in pipeline pressure difference, and the sealing performance is reliably guaranteed under various working conditions.
6. Self-cleaning structure of the sealing surface. When the ball is tilted away from the valve seat, the fluid in the pipeline evenly passes through the sealing surface of the ball at 360 °, which not only partially scours the valve seat from the high-speed fluid, but also flushes the accumulation on the sealing surface to achieve the purpose of self-cleaning.
The three-piece ball valve has the following advantages:
1. The fluid resistance is small, and the resistance coefficient is equal to that of the pipe section of the same length.
2. Simple structure, small size and light weight.
3. It is tight and reliable. At present, the sealing surface materials of ball valves are widely used in plastics and have good sealing performance. They are also widely used in vacuum systems.
4. It is easy to operate and quick to open and close. It only needs to rotate 90 ° from fully open to fully closed to facilitate remote control.
5. The maintenance is convenient, the structure of the ball valve is simple, the sealing ring is generally movable, and the disassembly and replacement are more convenient.
6. When fully open or fully closed, the sealing surfaces of the ball and the valve seat are isolated from the medium. When the medium passes through, it will not cause corrosion of the valve sealing surface.
7. It has a wide range of applications, from small diameters to a few millimeters to a few meters, from high vacuum to high pressure.
