Suppose there is a water supply pipe with a cover. Water is injected from the bottom of the pipe and discharged toward the pipe mouth. The cover of the water outlet pipe is equivalent to the closing member of the stop valve. If you lift the pipe cover upward with your hand, the water will be discharged. Cover the tube cap with your hand, and the water will stop swimming, which is equivalent to the principle of a stop valve.
Features of globe valve:
Simple structure, high rigor, convenient manufacturing and maintenance, large water friction resistance, can control the flow; when installed, low in and high out, directional; specifically used in hot and cold water supply and high-pressure steam pipes, not suitable To remove particles and highly viscous solvents.
Ball valve working principle:
When the ball valve rotates 90 degrees, the spherical surfaces should all appear at the inlet and outlet, thereby closing the valve and stopping the flow of solvent. When the ball valve rotates 90 degrees, the ball opening should appear at both the inlet and the intersection, allowing it to swim with almost no flow resistance.
Ball valve characteristics:
Ball valves are very convenient, fast and labor-saving to use. Usually, you only need to turn the valve handle 90 degrees. Moreover, ball valves can be used on fluids that are not very pure (containing solid particles) because its ball-shaped valve core changes the fluid when opening and closing. is the cutting movement.
Gate valve working principle:
Gate valve, also called gate valve, is a commonly used valve. Its closing working principle is that the gate sealing surface and the valve seat sealing surface are highly smooth, flat and consistent, and fit together to block the flow of medium liquid, and improve the sealing performance with the help of a spring or a physical model of the gate plate. actual effect. The gate valve mainly plays the role of cutting off the flow of liquid in the pipeline.
Gate valve features:
The sealing performance is better than that of the stop valve, the fluid friction resistance is small, opening and closing is less laborious , the sealing surface is less eroded by the solvent when fully open, and is not limited by the material flow direction. It has dual flow directions, small structural length, and wide application fields. The size is high, a certain amount of space is required for operation, and the opening and closing time interval is long. The sealing surface is easily eroded and scratched during opening and closing. The two sealing pairs cause problems for production, processing and maintenance.
Summary of the differences between globe valves, ball valves and gate valves:
Ball valves and gate valves are usually used to control on/off and cut off fluids, but cannot usually be used to adjust flow. In addition to controlling on/off and cutting off fluids, stop valves can also be used to adjust flow. When you need to adjust the flow rate, it is more suitable to use a stop valve behind the meter. For control switching and flow-cutting applications, gate valves are used due to economic considerations. Gate valves are much cheaper. Or use gate valves on large-diameter, low-pressure oil, steam, and water pipelines. Considering the tightness, ball valves are used. Ball valves can be used in working conditions with high leakage standards, are suitable for quick start and close, and have better safety performance and longer life than gate valves.
Post time: Aug-31-2023