Many cities in China have already had the "rotation" problem of the water meter of the high-rise residential households. Except for the problems of water meter itself and pipeline leakage, most of the water tables are self rotating after two times of pressurized water supply. The pipes are prone to air pressure and unstable pressure. This problem can be solved by installing the check valve. "The air rotation caused by pressure difference can be installed in front of the table to stop the return valve, and the check valve can prevent water from reflow. When the water pressure rises, the water meter is turning; and when the pressure is reduced, the check valve will automatically shut down and the water meter will not turn. When the pressure rises again, the water meter will not turn as long as the pressure is not high over the pressure in the back valve. "
Check valve also known as a one-way valve or reverse check valve, its role is to prevent the reverse flow of medium in the medium. Pump water off the bottom valve check valve also belongs to class. The valve is opened or closed by the flow and strength of the medium, and the valve is called the check valve to prevent the reverse flow of the medium. The check valve is a type of automatic valve, which is mainly used in the medium and one-way flow of the pipe, only allow the medium to flow in one direction to prevent accidents. Usually, the valve opens the valve disc under pressure and flows from the inlet side to the outlet side. When the pressure of the inlet side is lower than the outlet side, the valve automatically closes the channel under the action of fluid pressure and its own gravity to prevent the counterflow of the fluid. According to the different movement of the valve, the check valve is divided into 3 types: lift type, swing type and butterfly type. The valve body of the lifting type check valve is similar to the cut-off valve body, and its fluid resistance is larger. This type of check valve is high pressure and small caliber, and the ball valve is often used. Swing check valve has less resistance to fluid. It is generally suitable for medium and small caliber, low pressure and large diameter pipelines, and multiple valves are often installed on the valve clapboard of the valve to become multiple valves. The butterfly check valve is similar to the butterfly valve. It is simple in structure and small in resistance to fluid. If the check valve is closed too fast, it may cause liquid shock in the liquid pipe, produce noise, and even cause damage to the valve parts. In order to avoid this, a check valve with a buffer function can be used to prolong the closing time.
The installation should be noted as follows:
1, do not make the check valve bear the weight in the pipeline. Large aetv One-way valve should be independently supported, so that it is not affected by the pressure generated by the piping system.
2, when installing, the direction of the flow of the medium should be in accordance with the direction of the body's arrow.
3, lift type vertical valve check valve (One-way valve): should be installed on the vertical pipe.
4. The lift horizontal valve check valve should be installed on the horizontal pipe.