Check valve selection

1), aetv One-way valve: generally suitable for cleaning media, should not be used for containing solid particles and a larger viscosity medium. 2) For aetv One-way valve below DN50mm, butterfly check valves, vertical lift check valves and diaphragm check valves are recommended. For DN greater than 200mm and less than 1200mm Low-pressure non-return valve, should choose no wear ball valve; For DN greater than 50mm, less than 2000mm low-pressure check valve, should choose butterfly check valve and diaphragm check valve. 3) The diaphragm check valve is suitable for easy to produce water hammer on the pipeline, the diaphragm can be very good to eliminate the water hammer caused by the media counter-current, but the temperature and pressure limits, generally used in low-pressure room temperature pipe. 4) For the requirements of water hammer stroke when the impact is relatively small or no water hit the pipe, should use the slow closing Swing Check Valve and slow closing butterfly check valve. 5, construction, installation points 1), installation location, height, direction of import and export must meet the design requirements, pay attention to the direction of the flow of media should be consistent with the direction of the arrow marked body, the connection should be firmly. 2), the appearance of the valve must be installed before the inspection, the valve nameplate should be consistent with the current national standard "General Valve Flags" GB 12220 requirements. For the working pressure is greater than 1.0 MPa and the main pipe to play the role of cut-off valve, the installation should be carried out before the intensity and tightness test, qualified after the standard use. Strength test, the test pressure of 1.5 times the nominal pressure, the duration of not less than 5min, valve housing, packing should be no leakage as qualified. Tightness test, the test pressure of 1.1 times the nominal pressure; test duration in line with the requirements of GB 50243. 3) Do not subject the check valve to heavy loads in the pipeline. Large aetv One-way valve: Independently supported so that it is not affected by the pressure generated by the piping system. Construction, installation points 1), installation location, height, import and export direction must meet the design requirements, the connection should be solid and tight. 2), installed in the insulation pipe on all types of manual valves, the handle shall not be down. 3), the appearance of the valve must be installed before the inspection, the valve nameplate should be consistent with the current national standard "General Valve Flags" GB 12220 requirements. For the working pressure is greater than 1.0 MPa and the main pipe to play the role of cut-off valve, the installation should be carried out before the intensity and tightness test, qualified after the standard use. Strength test, the test pressure of 1.5 times the nominal pressure, the duration of not less than 5min, valve housing, packing should be no leakage as qualified. Tightness test, the test pressure is 1.1 times the nominal pressure; test pressure in the test duration should be consistent with GB 50243 standard requirements, no leakage valve plate sealing as qualified.

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