Check valve


Check valve refers to a valve whose opening and closing […]

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.
The movement of the disc is divided into lift type and swing type. 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. The combination of check valve and stop valve can play the role of safety isolation. The disadvantage is that the resistance is large and the sealing performance is poor when closed.

The valve that opens or closes on its own by the force of the flow of the medium to prevent the medium from flowing back is called a check valve. Check valves belong to the category of automatic valves, which are mainly used in pipelines where the medium flows in one direction, and only allow the medium to flow in one direction to prevent accidents.
Structure classification
According to the structure, it can be divided into three types: lift check valve, swing check valve and butterfly check valve:
1. Lift check valves are divided into two types: vertical and horizontal.
2. The swing check valve is divided into three types: single, double and multiple.
3. The butterfly check valve is a straight-through type.
The above check valves can be divided into four types in connection form: threaded connection, flange connection, welding connection and wafer connection.
Material classification
1. Cast iron check valve
2. Brass check valve
3. Stainless steel check valve
4. Carbon steel check valve
5. Forged steel check valve
Function classification
1.DRVZ silent check valve
Stainless steel check valve
Stainless steel check valve
2. DRVG silent check valve
3.NRVR silent check valve
4. SFCV rubber flap check valve
5. DDCV double disc check valve