1. The disc of the rubber lined check valve is disk-shaped and rotates around the rotating shaft of the valve seat channel. Because the channel in the valve is streamlined, the flow resistance is smaller than that of the butterfly type check valve. Butterfly check valve is divided into single disc type, double disc type and half type three, these three forms are mainly divided according to the valve diameter, the purpose is to prevent the medium from stopping the flow or backflow, weaken the hydraulic impact.
2,Rubber lined check valve: valve disc sliding along the vertical center line of the valve body check valve, noise check valve can only be installed on the horizontal pipe, in the high pressure small caliber check valve disc can be used ball. The body shape of the silencing check valve is the same as that of the globe valve (can be universal with the globe valve), so its fluid resistance coefficient is larger. Its structure is similar to the globe valve, and the body and disc are the same as the globe valve. The upper part of the disc and the lower part of the valve cover are processed with a guide sleeve, and the disc guide can be lifted and lowered freely in the valve cap guide. When the medium is flowing, the disc is opened by the medium thrust, and when the medium stops flowing, the valve disc lands on the seat by the vertical side to prevent the medium from countercurrent. Straight-through butterfly check valve medium inlet and outlet channel direction and seat channel direction perpendicular; Vertical lift check valve, the medium inlet and outlet channel direction and seat channel direction is the same, the flow resistance is smaller than straight through.
3. Rubber lined check valve: the valve disc slides along the center line of the valve body. Pipe type check valve is a new valve, its small size, light weight, good processing technology, is one of the development direction of check valve. But the fluid drag coefficient is slightly greater than that of swing check valves.