Check valve is an automatic valve used to open when the pipeline system medium is downstream and close when the counter current. The main function is to prevent the back flow of the medium, pump and drive mechanical reversal, prevent the water strike wave generated when the pump and drive motor suddenly stop running, and reduce the damage to the pipeline system. According to the relative displacement mode of the closed parts and the valve seat, the PVC Ball Check Valve can be divided into five categories:Swing Check Valve,Wafer Check Valve,Ball Check Valve, lifting type, turning type, disc type, diaphragm type and spherical check valve. For the above check valves, most have the following disadvantages: "loud noise" and vibration caused by the water hammer; the vibration between the "joint parts" in the valve shaft and the shaft, the mechanical friction between the shaft and the valve plate vibration frequency, valve plate displacement, seal failure, sometimes cause the valve plate off, system protection failure; valve fluid flow disorder, large flow resistance loss, serious energy loss. In order to avoid and improve the above shortcomings, the spherical PVC Check Valve, with its good sealing and small flow resistance and other performance advantages, has been widely used and promoted. Its structure is gradually improved from the initial "single ball" check valve to the "independent multi-channel multi-ball" Plastic Check Valve.
Check valve is one of the most commonly used equipment types for fluid transmission. The existing check valve has the problems of large resistance and large energy consumption. Reducing the flow resistance coefficient is an important way to save energy in fluid transmission. Common check valves include spherical check valve, pair clip check valve, etc. The common disadvantage of these check valves is that: when the fluid flow is moving forward, the check valve opens, some parts of the Ball Check Valve, such as the valve flap or the sphere, is in the center of the flow channel, there is a certain water retaining area, the resistance to the fluid flow is large, so that the effluent pressure is reduced, so the waste of energy.
Structure: the spherical check valve is a kind of multi-ball, multi-flow channel, multi-cone inverted fluid structure of the check valve, mainly composed of the front and rear valve body, rubber ball, cone body, etc.
Working principle: the rubber ball in the ball cover for a short stroke rolling to achieve the opening and closing of the valve. When the pump is started, the water drives off the rubber ball under the pressure to roll the glue ball to the right side by the cone in the rear valve body to open the check valve. After the pump stops, force the rubber ball due to the backwater pressure in the pipeline system to close the check valve. The rubber ball adopts hollow steel ball. The external elastic rubber can ensure both sealing and reduce the damage to the pipe system in the process of valve closing. When the valve opens, the cone with holes in the body plays a fixed role on the steel ball and eliminates the pressure of the contact area between the rubber ball and the cone, making the contact a surface contact, and reducing the hydraulic loss caused by the trembling of the rubber ball in the valve body.