Check valve is the fluid can only flow along the water inlet, outlet medium can not return, commonly known as one-way valve. Check Valves Yes Check Valves Swing Check Valves are available in an unrestricted installation position and are usually mounted on a horizontal pipe but can also be mounted on a vertical or dump pipe. When installing the check valve, pay special attention to the flow direction of the medium so that the normal flow direction of the medium matches the direction of the arrow indicated on the body or the normal flow of medium will be cut off. Bottom valve should be installed at the bottom of the pump suction pipe. When the check valve is closed, the water hammer pressure is generated in the pipeline, can cause serious damage to the valves, piping or equipment, especially for large high-pressure line or the outlet line, so that attention should be noted that the check valve's selection . Non-return valve is only for preventing one-way opening and closing valve of various types of pipeline or equipment on the countercurrent of fluid medium. Other types of check valves are widely used, there are many types, the following is the check valve for water supply and heat: 1, spring type: liquid from the bottom up, rely on pressure from the top of the spring-controlled valve flap, the pressure disappears, the spring Force the valve pressure, closed liquid back. Commonly used in smaller check valves. 2, gravity type: Similar to the spring type, rely on the gravity of the valve flap closed to prevent backflow. 3, Swing type: liquid in the valve body through, rely on pressure to open the side of the rotary valve flap, the pressure loss, the valve flap back by gravity, the reverse of the liquid pressure to close the valve. 4. Plastic diaphragm type: the shell and the diaphragm are plastic. The general shell is ABS, PE, PP, NYLON, PC. Diaphragm with silicone, fluororesin, etc .. Other check valve (check valve) Check valve, air defense explosion-proof valve and liquid check valve principle is more or less the same. More Keyword Search: Check Valve