High pressure check valves
High pressure check valve flow refers to rely on the media itself, and automatically open and close the valve disc, used to prevent the backflow medium valve door, and said, one-way valve, flow valve, non-return valve and the back pressure valve. Check valve belongs to a kind of automatic valve door, its main role is to prevent the backflow medium, to prevent the pump and drive motor reversal, and the discharge of the container medium. The check valve can also be used to give the pressure could rise to more than the system pressure of the auxiliary system supply piping. The check valve can be divided into main swing check valves ( In accordance with the center of gravity rotating) And lift check valve ( Move along the axis) 。 The internal thread check valve, butterfly check valve is belong to this type of valve gate, which includes swing check valve and lift check valve. Swing check valve with the humble hinge institutions, there is also a freely like the door of the valve disc on the tilt of the valve seat surface. In order to ensure that the valve disc to reach every time on the surface of the valve seat appropriate location, in valve design hinge agencies, in order to have enough plug valve kai xuan space, and make the valve valve genuine and comprehensive engagement with the valve seat. All valve disc can be made from metal, can be embedded in the metal on leather, rubber, or synthetic coverage, depending on the use of performance requirements. Swing check valves in the fully open conditions, almost unimpeded fluid pressure, so the pressure drop through the valve door is relatively small. Lift check valve flap valve is located on the valve seat sealing surface in the valve body. The gate valve in addition to the valve disc is free to lift, like the rest of the cut-off valve, the pressure of fluid from the valve disc of the valve seat sealing surface lift, medium return led to back to the valve seat valve disc, and cut off the flow. According to the conditions of use, the valve valve can be all-metal structure, it can also be embedded in the valve disc shelves rubber mat or rubber ring form. Like a cut-off valve, fluid through the lift check valve channel is narrow, so the lift check valve through the pressure drop than the swing check valve bigger, and low temperature check valves are very few restrictions. A, high pressure check valve structure and installation method: 1, high pressure check valve valve valve disc, valve seat around tunnel axis rotation movement, because the valve passage into A streamlined, the flow resistance is smaller than l butterfly 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. Butterfly check valve points single type, double disc type and for the most part three, the three forms mainly by the valve gate diameter, the purpose is to prevent the backflow medium flow or stop, decrease hydraulic shock. 2, high-pressure non-return valve disc along the vertical center line of valve body sliding check valve, internal thread check valve can only be installed in horizontal pipe runs with the high pressure on small-bore non-return valve ball valve disc can be used. Butterfly check valve valve body shape and globe valve ( Globe valve with gm) Fluid resistance coefficient is larger, so it. Its structure is similar to cut-off valve, the valve body and valve disc is the same as the cut-off valve. Valve flap of the upper and lower part of the valve cover processing has a guide sleeve, Jane Jane valve disc guide can be freely within the valve light guide Jane, when the downstream of the medium, the valve disc by medium thrust open, when stop the flow of medium, the valve disc on the vertical landing on the valve seat, prevent medium counter-current role. Straight-through butterfly check valve medium import and export the channel direction and the valve seat vertical direction; Vertical lift check valves, import and export of its media channel direction and the valve seat in the same direction, its a straight-through flow resistance is small. 3, high pressure check valve: the valve disc around the valve seat of pin shaft rotate within the check valve. Disc check valve has simple structure, can only be installed in horizontal pipe runs, sealing is good. 4, high pressure check valve: the valve disc along the center line of valve body sliding gate valve. Pipeline check valve is a new kind of valve door, its small size, light in weight and good processing technology, is one of the non-return valve development direction. But the fluid drag coefficient is slightly superior to swing check valves. 5, high pressure check valve: the valve door is used as boiler feed water and steam to cut off the valve, it can lift check valve and globe valve or Angle of comprehensive function of the valve. In addition, there are & ndash; Some is not suitable for pump discharge to install the check valve, such as the bottom valve, spring loaded, Y type check valve, etc. B, high pressure check valves use and performance specification: the gate valve used in industrial pipeline for preventing medium counter-current device. Performance specification C, action principle and structure of high pressure check valve: the valve door in use process, medium according to the graphic flow direction arrow. 1, when the medium flow direction by the regulation, the role of the valve disc force by the medium, be opened; Medium counter-current, due to the weight of the valve disc and valve disc reverse force by the medium effect, make the valve disc and the valve seat sealing surface and shut down, to achieve the purpose of preventing medium counter-current. 2, the sealing face of valve body and valve disc is made of stainless steel welding. 3, press GB12221 - the structure of the valve gate length The provisions of the 1989 according to JB/T79 - flange connection size The provisions of the 1994.