Introduction of wafer check valve
Aug 06, 2020
is also known as the counter flow valve. This kind of valve is automatically opened and closed by the force generated by the flow of liquid itself, belonging to an automatic valve.
The function of this type of valve is to allow the medium to flow in one direction only and to prevent the flow in the opposite direction. Usually this kind of valve works automatically. Under the action of fluid pressure flowing in one direction, the valve disc opens; when the fluid flows in the opposite direction, the valve seat is acted by the fluid pressure and the self weight of the valve disc, and the flow is cut off. Among them, stainless steel wafer type check valve belongs to this type of valve, which includes swing check valve and lift check valve. Swing check valve has a hinge mechanism, and a valve disc like a door is free to lean on the inclined seat surface. In order to ensure that the valve disc can reach the proper position of the valve seat surface every time, the valve disc is designed in the hinge mechanism, so that the valve disc has enough swing space and makes the valve disc truly and comprehensively contact with the valve seat. The valve disc can be made of metal, inlaid with leather, rubber or synthetic cover, depending on the performance requirements. When the swing check valve is fully open, the fluid pressure is almost unimpeded, so the pressure drop through the valve is relatively small. The disc seat of lift check valve is located on the sealing surface of valve seat on the valve body.
Except that the valve disc can be lifted and lowered freely, the rest of the valve is like the stop valve. The fluid pressure makes the valve disc lift from the sealing surface of the valve seat, and the medium backflow causes the valve disc to fall back to the valve seat and cut off the flow. According to the service conditions, the valve disc can be all metal structure, or it can be inlaid with rubber pad or rubber ring on the valve disc frame. Like the globe 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 that of the swing check valve, and the flow rate of the swing check valve is limited.
The check valve is used in the pipeline system, its main function is to prevent the reverse flow of medium, prevent the pump and its driving motor from reversing, and discharge the medium in the container. The check valve can also be used to supply the auxiliary system in which the pressure may rise above the main system pressure. According to the different materials, check valve can be applied to all kinds of medium pipeline. When the check valve is installed on the pipeline, it becomes one of the fluid components of the whole pipeline. The opening and closing process of the valve disc is affected by the transient flow state of the system in which it is located; conversely, the closing characteristics of the valve disc have an effect on the fluid flow state.