Check Valves are a valve that automatically opens and closes the valve through the flow of the medium itself to prevent the backflow of the medium, also known as a check valve, check valve, reverse flow valve, and back pressure valve. The check valve is an automatic valve whose main function is to prevent the reverse flow of the medium, prevent the reverse rotation of the pump and the drive motor, and release the medium in the container.
Check valves may also be used to supply lines to auxiliary systems where the pressure may exceed the system pressure. Check valves are mainly divided into rotary check valves (rotating with the center of gravity) and lift check valves (moving along the axis). Check valve This type of valve only allows the medium to flow in one direction and acts to prevent flow in the opposite direction. Usually, such a valve works automatically, the valve flap is opened due to the fluid pressure flowing in one direction, and when the fluid flows in the opposite direction, the fluid pressure and the self-polymerizing valve body of the valve body act on the valve seat to block the flow.
Among them, the check valve is this type of valve, there is a rotary check valve and lift check valve. The rotary check valve freely abuts on the valve seat surface of the valve body, such as a door, which is inclined through a hinge mechanism. In order to ensure that the valve body reaches the proper position of the valve seat surface every time, the valve body is designed as a hinge mechanism, the valve body has enough space for rotation, and the valve body really touches the valve seat. The valve body can be made of metal or embedded in the metal with leather, rubber, or synthetic target surface, depending on the performance requirements.
Rotary check valves hardly impede the pressure of the fluid in the fully open state, so the pressure drop across the valve is relatively small. The lift check valve body is located on the seat sealing surface on the valve body. Except the valve body can rise and fall freely, the rest of the valve is like a globe valve. Under the pressure of the fluid, the valve body is lifted from the sealing surface of the valve seat, the medium flows back, the valve body returns to the valve seat, and the flow is blocked. Depending on the conditions of use, the valve body can be of an all-metal construction or in the form of a rubber seal or rubber ring embedded in the valve body frame.
Like globe valves, the passage of fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is greater than that of the rotary check valve, and the flow of the rotary check valve is rarely restricted.