Structural principle of check valve

The swing check valve has a hinge mechanism and a valve disc that is like a door and freely rests on the tilted valve seat surface. In order to ensure that the valve disc can reach the appropriate position on the valve seat surface every time, the valve disc is designed in a hinge mechanism, so that the valve disc has sufficient swing space and truly and comprehensively contacts the valve seat. The valve disc can be made entirely of metal, or it can be embedded with leather, rubber, or a synthetic cover on the metal, depending on the performance requirements. When the swing check valve is fully open, the fluid pressure is almost unobstructed, so the pressure drop through the valve is relatively small. The disc of the lift check valve is located on the sealing surface of the valve seat on the valve body. Except for the free lifting and lowering of the valve disc, the rest of this valve is like a globe valve. Fluid pressure lifts the valve disc from the sealing surface of the valve seat, and the medium backflow causes the valve disc to fall back onto the valve seat, cutting off flow. According to the usage conditions, the valve disc can be an all metal structure, or it can be in the form of embedded rubber pads or rings on the valve disc holder. Like globe valves, the passage of fluid through lift check valves is also narrow, so the pressure drop through lift check valves is greater than that of swing check valves, and the flow rate of swing check valves is limited very little.