Check valve allows medium to flow in one direction, stopping counter flowing. The valve operates automatically. With the pressure of fluids, the disc opens. When fluids counter flowing, pressure make disc coincide with base and cut off medium.
Check valve is classified into
swing check valve and
lift check valve.
Swing check valve has a hinge. To ensure disc can reach to the appropriate position on base, the disc is put inside hinge so that disc has adequate swing space and makes disc contact with base completely. Disc is made of metal, or inlaid with leather, rubber or synthetic material, based on requirements. When swing check valve opens completely, pressure of fluid has no block. For that, pressure on valve is low.
The disc of
lift check valve is located at the sealing face of upper base on the valve. The disc can lift freely. The pressure of fluids raises the disc from the sealing face of base. Back flowing of medium push disc back to base and cut off flowing. According to utilizing conditions, the disc can be made of metal or inlaid with rubber shim or rubber ring. The channel of swing check valve, medium flowing through, is narrow. For that, the pressure on lift check valve is higher than swing check valve, and flow of swing check valve has less limitation.
