The check valve belongs to this type of valve, which generally includesLift check valve, Swing check valve. The swing check valve has a hinge mechanism, and a door-like disc freely leans on the inclined seat surface.
The function of this type of valve is to only allow the medium to flow in one direction and prevent the flow in one 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 on by the fluid pressure and the self-weight of the valve disc to cut off the flow.
In order to ensure that the valve clack can reach the proper position of the seat surface every time, the valve clack is designed in the hinge mechanism, so that the valve clack has enough swing space, and makes the valve clack truly and comprehensively contact with the valve seat. The disc can be made entirely of metal, or it can be inlaid with leather, rubber, or a synthetic covering on the metal, depending on the requirements of performance. 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 of the lift check valve is seated on the sealing surface of the valve seat on the valve body.
Except that the valve disc can rise and fall freely, the rest of the valve is like a globe valve. The fluid pressure makes the valve disc lift from the sealing surface of the valve seat, and the backflow of the medium causes the valve disc to fall back to the valve seat and cut off the flow. According to the conditions of use, the valve clack can be of all-metal structure, or in the form of inlaid rubber pads or rubber rings on the valve clack frame. 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 that of the swing check valve, and the flow rate of the swing check valve is limited. rare.
The above is all the content about the selection of valves to prevent medium backflow shared by Xiao Valve today. I hope it can help you in need~