The use of brass check valve
A, swing check valve: swing brass check valve flap is disc-shaped, rotating movement around the axis of the valve seat channel, because the valve channel into a streamline, flow resistance than the lift
The flow resistance is smaller than the ascending and descending check valve, suitable for low flow rate and flow does not often change the large-diameter occasions, but not for pulsating flow, its sealing performance is not as good as lifting type. Swing check valve is divided into single, double and more than half of the three forms of valve caliber, the purpose is to prevent the media to stop flowing or backflow, weakening the hydraulic impact.
Second, the lift check valve: the valve flap along the vertical centerline of the body slide check valve, lift check valve can only be installed in the horizontal pipeline, in the high pressure small diameter check valve on the valve flap can be used round ball. Lift check valve body shape and globe valve - the same can be common with the globe valve, so it has a large fluid resistance coefficient. Its structure is similar to the globe valve, the valve body and valve flap and the same globe valve. The upper part of the valve flap and the lower part of the valve cover is processed with a loud sleeve Jane, the valve guide Jane can be freely lifted in the valve jan guide Jane, when the media flow, the valve flap by the media thrust open, when the media stop flowing, the valve flap by the self-hanging landing on the valve seat, play a role in stopping the media backflow. Straight lift check valve media import and export channel direction and seat channel direction perpendicular; vertical lift check valve, the quality of the import and export channel direction and seat channel direction, the flow resistance is smaller than the straight type.
Third, the disc check valve: the flap rotates around the pin in the valve seat check valve. Disc check valve structure is simple, can only be installed in the horizontal pipeline, the seal is poor.
Fourth, the pipe-type brass check valve: the valve flap slides along the centerline of the valve body. Pipe-type check valve is a new kind of valve, its small size, light weight, processing
Process is good, is the development direction of the check valve -. But the fluid resistance coefficient than the swing check valve is slightly larger.
Fifth, the pressure check valve: this valve [ ] is made for boiler water and steam shut-off valve, it has a lift check valve and globe valve or angle valve integrated function.
In addition, there are some brass check valves that are not suitable for pump outlet installation, such as bottom valves, spring type, Y-type check valves.
Check valve principle of operation
Check valve is to rely on the medium itself flow and automatically open and close the valve flap, used to prevent the backflow of media valves, also known as check valves, check valves, backflow valves and back pressure valves. Check valve is an automatic valve, the main role is to prevent the backflow of the medium, to prevent the pump and drive motor reversal, as well as the release of the container medium. Check valves can also be used to provide recharge to the auxiliary system in which the pressure may rise above the system pressure. Check valves can be mainly divided into swing check valves rotate according to the center of gravity and lift check valves move along the axis. Check valves of this type] serve to allow the medium to flow in one direction only, and to prevent flow in the opposite direction. Usually this kind of valve is automatic work, in a direction of flow of fluid pressure, the valve flap open; fluid flow in the opposite direction, by the fluid pressure and the valve flap of the self-gravity of the valve flap act on the valve seat, thus cutting off the flow. Among them, check valves belong to this type of valve, which includes swing check valves and lift check valves. Swing check valves have a hinge mechanism, and a door-like flap that rests freely on the surface of the inclined seat. In order to ensure that the flap reaches the proper position on the seat surface every time, the flap is designed to be hinged so that the flap has sufficient swing space and true, full contact with the seat. The valve can be made entirely of metal, or can be inlaid with leather, rubber, or synthetic coverings, depending on the performance requirements. Swing-open check valves are fully open, the fluid pressure is almost unobstructed, so the pressure drop [through the valve] is relatively small. The lift check valve has a flap located on the sealing surface of the valve seat on the valve body. In addition to the valve flap can be raised and lowered freely, the valve is partly like a globe valve, fluid pressure causes the valve flap to lift from the seat sealing surface, and the media backflow causes the valve flap to fall back to the seat and cut off the flow. Depending on the conditions of use, the valve can be all-metal structure, but also in the form of rubber gasket or rubber ring inlaid on the valve frame. Like the globe 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 the swing check valve, and the flow of the swing check valve is very little restricted.
The main role of brass check valve
-、Clamp brass check valve use:
Check valve is installed in the pipeline system, the main role is to prevent the backflow of media, check valve is a kind of automatic valve relying on the pressure of the medium to open and close. Clamp check valve is suitable for nominal pressure PN1.0MPa ~ 42.0MPa, Class150 ~ 25000; nominal diameter DN15 ~ 1200mm, NPS1/2 ~ 48; working temperature - 196 ~ 540°C of various pipelines, used to prevent the backflow of media. Through the choice of different materials, can be applied to water, steam, oil, nitric acid, acetic acid, strong oxidizing medium and uric acid and other media.
Second, the main material of the clamped check valve:
There are carbon steel, low temperature steel, duplex steel F51/F55, titanium alloy, aluminum bronze, Inconel, SS304, SS304L, SS316, SS316L, chromium-molybdenum steel, Naier 400/500, 20# alloy, Hastelloy and other metal materials. The use and structural characteristics of the clamped check valve
Three, the standards and specifications of the clamped brass check valve:
1, design and manufacture: API594, API6D, JB/T8937, JB/T3595,
2, structure length: API594, API6D, DIN3202, JB/T8937, ANSI/ASME B16.10
3, Reed, temperature grade: ANSI B16.34, DIN2401, GB/T9124, HG20604, HG20625, SH3406, JB/T74
4、Test and inspection: API598, JB/T9092, GB/T13927
5、Pipe flange: JB/T74~90, GB/T9112-9124, HG20592~ 20635, SH3406, ANSI/ASME B 16.5, DIN2543-2548.
GB/T13402, API605, ASMEB17
Fourth, the structural characteristics of the clamp brass check valve:
1, the structure length is short, its structure length is only 1/4~1/8 of the traditional flange check valve
2, small volume, light weight, only 1/4~1/20 of the traditional flange check valve
3、The valve flap closes quickly and the water hammer pressure is small
4, horizontal or vertical pipeline can be used, easy to install
5, smooth flow, small fluid resistance
6、Sensitive action, good sealing performance
7、Short stroke of valve flap, small closing impact
8、The overall structure is simple and compact, beautiful shape
9, long service life, reliable performance
The role of the check valve in the pump water supply system is to prevent the impact of high pressure water reflux on the pump impeller. When the pump suddenly stops running for some reason during the operation of the system, the pressure inside the pump disappears, and the high pressure water connected with the pump outlet will flow back to the pump. When the pump outlet is equipped with a check valve, it will immediately close to prevent the reverse flow of high-pressure water back to the pump. The function of check valve in hot water system is to prevent hot water from flowing back into the pipe. If it is a PVC pipe it is likely to scald the pipe and may even injure someone, especially in a solar water heater system.
