[Science Stickers] 3D Demonstration of Check Valve Working Principle and Troubleshooting

Check valve refers to a valve whose opening and closing parts are circular discs and rely on its own weight and medium pressure to generate actions to block the back flow of the medium. It is an automatic valve, also known as check valve, one-way valve, return valve or isolation valve.

Working principle of check valve

Check valves can be divided into swing check valves (rotating according to the center of gravity) and lift check valves (moving along the axis). The lift check valve is similar in structure to the shut-off valve, but lacks the valve stem that drives the disc. The medium flows in from the inlet end (lower side) and flows out from the outlet end (upper side). When the inlet pressure is greater than the sum of the weight of the disc and its flow resistance, the valve is opened. On the contrary, the valve is closed when the medium flows back. The swing check valve has a disc that is inclined and can rotate around the axis, and the working principle is similar to that of the lift check valve. The check valve is often used as the bottom valve of the pumping device to prevent the backflow of water. Like a shut-off valve, the passage of fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow rate of the swing check valve is restricted. Rarely. The combination of check valve and stop valve can play a role of safety isolation. The disadvantage is that the resistance is large and the sealing performance is poor when closed.

Troubleshooting of check valve

Broken disc

The reason for the disc breaking is

The pressure of the medium before and after the check valve is close to balance and they are "see-saw" each other. The valve disc is often beaten against the valve seat, and the disc made of some brittle materials (such as cast iron, brass, etc.) is broken.

The preventive method is to use a check valve whose disc is a flexible material.

Medium backflow

The reasons for the backflow of the medium are

①The sealing surface is damaged; ②Insert impurities.

Repairing the sealing surface and cleaning impurities can prevent backflow.

This article comes from the Internet, only for learning and communication, no commercial purpose.

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