Check valve is to rely on the flow of the medium itself […]
Check valve is to rely on the flow of the medium itself automatically open and close the valve flap, used to prevent the media back to the valve. Check valve is an automatic valve, its main role is to prevent media backflow, to prevent the pump and drive motor reversal, and the release of container media. Check Valve This type of valve is designed to allow only medium to flow in one direction and to prevent it from flowing in the opposite direction. Usually this kind of valve is automatic working, the valve flap opens under the fluid pressure flowing in one direction; when the fluid flows in the opposite direction, the valve flap is acted upon by the fluid pressure and the self-weight of the valve flap to cut off the flow.
Swing check valve disc is disc-shaped, around the valve seat channel for rotational movement shaft, because of the valve into the streamline, the flow resistance than the lift check valve for low flow rate and flow changes rarely Of the large-diameter occasions, but not for pulsatile flow, the sealing performance is less than the lift. Swing check valve is divided into single valve type, double valve type and most of the three types, these three forms are mainly divided by the valve caliber, the purpose is to prevent the media stop flowing or backwards, weakened the hydraulic impact.
Lift check valve flap located on the valve seat sealing surface. In addition to the valve flap valve can be free to rise and fall, the rest of the same as the cut-off valve, the fluid pressure so that the valve flap from the valve seat lifting surface, the media back to cause the valve flap down to the seat, and cut off the flow. According to the conditions of use, the valve disc can be all-metal structure, it can be in the valve frame inlaid rubber pad or rubber ring form. Like the stop 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 the swing check valve, and the flow of the swing check valve is less limits.
Disc check valve structure is simple, can only be installed on the horizontal pipe, the sealing is poor. Pipeline check valve is a new type of valve, its small size, light weight, good processing technology, is one of the development direction of the check valve. But the fluid resistance coefficient is slightly larger than the swing check valve.