What are the structural characteristics of butterfly valves?

Butterfly check valve refers to the valve that automatically opens and closes the disc depending on the flow of the medium itself to prevent the medium from flowing backwards, also known as check valve, one-way valve, reverse flow valve and back pressure valve. Check valve is an automatic valve, its main function is to prevent the medium from flowing backwards, prevent the pump and driving motor from reversing, and release the medium in the container. Check valves can also be used in pipes supplying water to auxiliary systems, in which the pressure may rise above the system pressure. Check valves can be mainly divided into swing check valves (rotating according to the center of gravity), lifting check valves (moving along the axis) and butterfly check valves (rotating along the center).

Structural characteristics of butterfly check valve;

Butterfly check valves include swing check valves and lift check valves. Swing check valve has a hinge mechanism, and a disc like a door is freely supported on the inclined seat surface. In order to ensure that the disc can reach the proper position of the valve seat surface every time, the disc is designed in the hinge mechanism, so that the disc has enough swing space to make the disc truly and comprehensively contact with the valve seat. According to the performance requirements, the disc can be completely made of metal or inlaid with leather, rubber or synthetic materials. When the swing check valve is fully opened, the fluid pressure is almost unimpeded, so the pressure drop through the valve is relatively small. The disc of the lifting check valve is located on the sealing surface of the upper valve seat of the valve body. This valve is similar to a globe valve except that the disc can be lifted freely. The fluid pressure makes the disc lift from the sealing surface of the valve seat, and the medium backflow makes the disc fall back to the valve seat, cutting off the flow. Depending on the service conditions, the disc can be all-metal structure, or it can be in the form of embedding rubber pads or rubber rings on the disc frame. Like the globe valve, the passage of fluid through the lift check valve is very narrow, so the pressure drop through the lift check valve is greater than that of the swing check valve, and the flow rate of the swing check valve is rarely limited.