Introduction of Check Valves via Pictures and Check Valve Diagram

A check valve, also known as a non return valve or one way valve, is a valve allows the fluid to flow in only one direction, while automatically closing to prevent the backflow of the fluid in the opposite direction. The types of check valves are various and complex. Commonly used check valves according to different structures, mainly include lift check valves, swing check valves and butterfly check valves; as well as slow-closing check valves generally used at the water outlet of water pumps, which is mainly as a water pump check valve.For example in the fire protection system, check valves are widely used to control the one way flow of fluids.

Check valves need to be installed at positions where water backflow needs to be prevented, such as the outlet pipelines of fire pumps, fire pump adapters, and the outlet pipelines of rooftop water tanks.

Pictures and Check Valve Diagram

Lift Check Valve

The structure of a lift check valve is generally similar to that of a globe valve. Its valve disc moves up and down along the centerline of the passage. The action is reliable, but the fluid resistance is relatively large, making it suitable for occasions with smaller diameters.

Swing Check Valve

The valve disc of a swing check valve rotates around the rotating shaft to open and close the valve. Its resistance is generally smaller than that of a lift check valve, and it is suitable for occasions with larger diameters.

Butterfly Check Valve

The valve disc of a butterfly check valve is in the shape of a disc as it is named, and rotates around the rotating shaft of the valve seat passage.

Slow-closing Check Valve

The main valve core is made to move slowly up and down by utilizing the self pressure of water, so as to achieve the effect of slow opening and closing. This type of valve is generally installed at the water outlet of the fire pump. It is helpful in eliminating and alleviating water hammer, avoid water pump freom running in reverse, and also realize the functions of slow closing, noise elimination and check.
The structure is as shown in the following slow-closing check valve diagram: