Characteristic and Application of One-way Valve

Characteristic and Application of One-way Valve

One-way valve is also called check valve or check valve. Used in hydraulic system to prevent reverse flow of oil flow, or in pneumatic system to prevent reverse flow of compressed air.

One-way valves are straight-through and right-angle. The straight-through one-way valve is installed on the pipeline by threaded connection. The right-angle one-way valve has threaded connection, plate connection and flange connection. Hydraulic control one-way valve, also known as locking valve or pressure retaining valve, is the same as one-way valve to prevent reverse flow of oil. But when the reverse flow of oil flow is needed in the hydraulic circuit, the oil pressure can be controlled and the one-way valve can be opened to make the oil flow flow in both directions. Hydraulic control one-way valve uses conical spool, so the sealing performance is good. This valve can be used as one-way locking to keep pressure when sealing oil pipeline is required. There are two ways to control oil leakage by hydraulic one-way valve: internal and external. Internal leakage type can be used in oil pipeline without back pressure at reverse outlet of oil flow; otherwise, it is necessary to use external leakage type to reduce control oil pressure.

Characteristic

One-way valve is a directional control valve in which air flow can only flow in one direction but not in the opposite direction. Its working principle is the same as hydraulic one-way valve. Compressed air enters from P port, overcomes spring force and friction force to open the one-way valve port, and compressed air flows from P to A. When P port is uncompressed, under the action of spring force and residual force of A port (cavity), the valve port is closed, which makes the air flow from A to P impassable. One-way valves are used in situations where reverse flow of air is not allowed, such as when the air compressor inflates the gas tank, a one-way valve is set between the air compressor and the gas tank. When the air compressor stops working, the compressed air in the gas tank can be prevented from flowing back to the air compressor. One-way valves are often used with throttle valves, sequential valves and other synthetic one-way throttle valves, one-way sequential valves.

purpose

One-way valves have a wide range of applications, there are many types, the following is water supply and thermal check valves commonly used:

1. Spring type: liquid from bottom to top, relies on pressure to lift the valve disc controlled by spring. When the pressure disappears, the spring force will press the valve disc down and seal the liquid back flow. It is often used in check valves with smaller sizes.

2. Gravity type: Similar to spring type, the valve relies on its own gravity to seal and prevent backflow.

3. Swing type: liquid in the valve body through, relies on the pressure to top the rotating disc on one side, after pressure loss, the disc relies on self-weight to return, reverse liquid pressure to seal the disc.

4. Plastic diaphragm type: the shell and diaphragm are plastic. The general shell is ABS, PE, PP, NYLON, PC. Diaphragm has silicone resin, fluororesin, etc.

Other one-way valves (check valves), such as check valves for sewage discharge, explosion-proof valves for civil air protection and check valves for liquid use, have similar or similar principles.