The purpose of using the check valve is to prevent the upstream of the media, generally in the pump outlet to install check valve. In addition, check valves are also installed at the outlet of the compressor. In short, in order to prevent the media upstream, the device, device or pipe should be installed on the road check valve. Vertical lift check valve is usually used in the horizontal pipe on the nominal path 50mm. Straight-Through lift check valves can be installed on both horizontal and vertical pipes. The bottom valve is generally only installed on the vertical pipe inlet of the pump, and the medium flow from bottom to top.
Swing check valve can be made into a very high working pressure, PN can reach 42MPa, and DN can also be very large, the maximum up to 2000mm above. Depending on the material of the shell and seal, any working medium and any operating temperature range can be applied. The medium is water, steam, gas, corrosive medium, oil, food, medicine and so on. Medium operating temperature range between-196~800℃. The installation location of the swing check valve is not restricted, usually installed on the horizontal pipe, but can also be installed on the vertical pipe or inclined pipe.Butterfly Valve
The application of butterfly check valve is low pressure large caliber, and the installation situation is limited. Because the butterfly check valve's work pressure cannot do very high, but the nominal diameter can do very big, can reach above 2000mm, but the nominal pressure is in 6.4MPa below. Butterfly check valve can be made to clamp, generally installed in the pipe between the two flanges, the use of the form of the clamp connection. The installation position of butterfly check valve is unrestricted, can be installed on the horizontal pipe, or can be installed on the vertical pipe or inclined pipe road.Butterfly Valve
The diaphragm check valve is suitable for the water hammer which is easy to produce, and the diaphragm can remove the water hammer from the medium countercurrent. Because the diaphragm type check valve's working temperature and the use pressure are limited by the diaphragm material, generally uses in the low-pressure normal temperature tube road, specially is suitable for the pipeline road. General medium working temperature between-20~120℃, work pressure <1.6MPa, but the diaphragm check valve can do a larger caliber, the DN can be up to 2000mm above. The diaphragm type check valve has been applied more in recent years because of its excellent waterproof striking performance, simple structure and low manufacturing cost.
Spherical check valve because the seal is coated rubber sphere, so good sealing performance, reliable operation, good resistance to water hammer, and because the seals can be a single ball, but also can be made of multiple balls, so can be made into large caliber. But its seal is covered with rubber hollow sphere, not suitable for high-pressure piping, only applicable to the middle and low pressure pipe. Due to the spherical check valve shell material can be made of stainless steel, sealing pieces of the hollow sphere can be.
The straight-through type lift check valve should be installed on the horizontal pipe, the vertical lift type check valve and the bottom valve are generally installed on the vertical pipe, and the media flow from bottom to top. The installation position of the swing check valve is not limited, usually installed in the horizontal pipe, but can also be installed in the vertical pipe or the dumping pipeline. When installing check valves, special attention should be paid to the flow direction of the medium, so that the normal flow direction of the medium is consistent with the arrow direction indicated on the valve body, otherwise the normal flow of the medium will be truncated. The bottom valve should be installed at the bottom of the water pump suction pipe road. Check valve closed, will produce water hammer pressure in the pipeline, serious will lead to valve, pipeline or equipment damage, especially for large mouth lines or high-pressure piping, it should cause check valve selection of the high attention.Butterfly Valve