The classification of the check valve
Check valve according to its structure and installation method can be divided into: a, swing check valve, swing check valve disc in disc, seat channel around the axis of rotary motion, due to the channel into a streamline in the valve, flow resistance is smaller than lift check valve, suitable for low flow velocity and flow not often change the large diameter of occasions, but should not be used for oscillating flow, its sealing performance than lift. Swing check valve points single type, double disc type and for the most part three, the three forms mainly by the valve diameter, the purpose is to prevent the backflow medium flow or stop, decrease hydraulic shock. Second, lift check valve: disc along the vertical centerline of sliding body check valve, lift check valve can only be installed in horizontal pipe runs with the high pressure small check valve disc can be used on the ball. Lift check valve body shape and cut-off valve ( To stop valve general) Fluid resistance coefficient is larger, so it. Its structure is similar to cut-off valve, valve body and disc is the same as the cut-off valve. Disc upper part and lower part of the cover processing has a guide sleeve, Jane Jane disc guide can be freely within the valve light guide Jane, when the downstream of the medium, the disc by medium thrust open, when stop the flow of medium, the disc landing on the hanging on the seat, to prevent medium counter-current role. Straight-through lift check valve medium import and export channel direction and seat vertical direction; Vertical lift check valve, import and export of its media channel direction and seat in the same direction, its a straight-through flow resistance is small. Three, disc check valve: disc around seat pin shaft rotate within the check valve. Disc check valve has simple structure, can only be installed in horizontal pipe runs, poor sealing. Four, pipeline check valve: disc sliding along the center line of the body of the valve. Pipeline check valve is a new kind of valve, its small size, light in weight and good processing technology, is one of the check valve development direction. But the fluid drag coefficient is slightly superior to swing check valves. Five, the compression type check valve: the valve is used as boiler feed water and steam to cut off the valve, it can lift check valve and globe or Angle valves integrated function.