Piston check valve is the media itself flow automatically open and close the valve to prevent medium backflow valve, also known as a check valve, check valve, reflux valve, and backpressure valve. The check valve is an automatic valve, its main role is to prevent the media back to prevent the pump and drive motor reversal, as well as container media bleeder.
The check valve can also be used to pipeline pressure may rise to more than the system pressure auxiliary system to provide supplies. The non-return valve can be divided into the swing check valve (rotate by the center of gravity) and lift check valves (along the axis of movement).
The role of this type of valve is only allow the medium to flow in one direction, and stop the flow direction. Usually the valve is automatically work in a direction of flow of fluid under pressure, the valve opens; fluid flow in opposite directions, from the coincidence of the valve role of fluid pressure and the valve on the valve seat, thereby cutting off the flow.
1, Piston check valves on the valve disk-shaped around the seat channel the shaft for rotation, streamlined into a channel within the valve, the flow resistance than l butterfly valve small, suitable for low flow rate andmobile infrequently changing the large diameter occasions, but should not be used for pulsatile flow, the sealing performance is less than lift. Points univalve butterfly valve, double valve type, and mostly style, three points mainly in the form of valve size, to prevent the media to stop the flow or backflow, weakened hydraulic shock.
2, The check valve sliding piston check valve flap along the vertical centerline of the valve body, the internal thread check valve can be installed only in horizontal pipe, the valve can be used on the check valve of the high-pressure small-caliber ball.
3, Piston-type check valve: the valve around the check valve seat within the pin rotation. Simple disc check valve structure can only be installed in a horizontal pipe, sealing well.
4,Valve piston check valve: valve slide along the valve body centerline. Pipeline check valve is a valve emerging, its small size, light weight, good process is one of the check valve development direction. Fluid drag coefficient is slightly larger than the swing check valve.
5, Compression-type check valve: This valve is used as boiler feed water and steam cut off valve, it has a lift check valves and shut-off valve or angle valve function.
Piston check valves use and performance specifications:
This valve is used as a device to prevent the media counter-current industrial pipe.
Performance Specifications
Piston check valve action principle and structure description:
The valve in the process of using the medium flow direction of the arrow.
1, When the medium flow in the required direction, the role of the media force the valve is open; upstream medium by the media opposing force, due to the valve dead weight and valve, the valves and valve seat sealing surface density closed to prevent the media counter-current purposes.
2, The sealing surface of the valve body and the valve made of stainless steel surfacing.
3,Tthe length of the valve structure according to the provisions of GB12221-1989, flange connection size provisions of JB/T79-1994.
