Common Failures and method of the check valve

8873必赢bwin www.joshuaszostak.com check valve works the role

this type of valve is only to allow the medium to flow in one direction, but also to stop the flow direction. Usually the valve is automatically work in a direction of flow of fluid under pressure, the valve opens; fluid flow in opposite directions, from the coincidence of the valve role of fluid pressure and the valve on the valve seat, thereby cutting off the flow. Check them belonging to this type of valve, which includes a swing check valve and lift check valves. Swing Check Valve ordinary hinge, like there is a door flap valve against the seat tilt surface. In order to ensure that the valve every time to reach the appropriate location of the seat surface, the valve design in the hinge mechanism, so that the valve has sufficient swing space, and a real flap valve, full contact with the valve seat. All valve can be made of metal, leather, rubber, can also be embedded in the metal or synthetic cover, depending on the use of performance requirements. Swing check valve in the fully open position, virtually unimpeded fluid pressure is relatively small, so the pressure drop through the valve. Lift check valve valve seat sealing surface located in the body. This valve, in addition to the valve is free to lift, like the rest of the shut-off valve as the fluid pressure valve seat sealing surface lift the medium return valve seat valve down and cut off the flow. Depending on the operating conditions, the valve can be all metal construction, the form of a rubber mat or rubber ring in the the valve flap rack inlaid. As shut-off valve, the fluid through the check valve lift channel is narrow, so lift check valve pressure drop than swing check valve, swing check valve flow by restrictions very little. the check valve common faults and treatment

common faults: ① disc break; ② media back.

cause disc break because:

check valves before and after the pressure of the medium is close to equilibrium are mutually "see-saw" state the clapper often beat with the valve seat, certain brittle materials (such as cast iron, brass, etc.) made of the valve flap broken.

prevention approach is the use of the valve is a check valve of ductile materials.

media back: ① sealing surface damage; ② folder into the impurity. Repair the sealing surface and cleaning impurities, can prevent the back.