How many kinds of check valves should be used?
Check valve applies to the occasionThe purpose of the utility model is to prevent the backflow of the medium, and the half of the utility model is provided with a check valve at the outlet of the pump. In addition, a check valve shall be installed at the outlet of the compressor. In a word, check valves shall be installed on the equipment, installations or pipelines to prevent the flow of the medium.Generally in the nominal diameter of 50mm horizontal pipelines are selected vertical lift check valve. Straight through lift check valves can be installed on both horizontal and vertical lines. At the end of the valve is generally installed in the vertical pipe of the pump inlet, and the bottom-up flow of media.Swing check valve can be made at a high working pressure, PN up to 42Mpa, and DN can also do great, maximum up to 2000mm or more. Depending on the material of the housing and the seal, any working medium and any operating temperature range can be applied.
Medium for water, steam, gas, corrosive media, oil, food, drugs and so on. The medium operating temperature range is between -196~800 degrees centigrade.Swing check valves are installed in an unrestricted position, usually installed on a horizontal pipe, but can also be mounted on a vertical or inclined pipe.Butterfly check valve is suitable for low pressure large diameter, and installation occasions are limited. Because the butterfly valve of the working pressure can not be high, but the public can be large, can reach more than 2000mm. But nominal pressure is below 6.4Mpa. Butterfly check valve can be made into pairs, generally installed in the pipeline between the two flanges, using the form of clamp connection.Butterfly check valves are installed in an unlimited position and can be mounted on horizontal or vertical or sloping lines.Diaphragm type check valves are suitable for pipes that are prone to water hammer. The diaphragm can eliminate the water hammer produced by the medium counter flow. As the diaphragm type check valve operating temperature and practical pressure by the diaphragm material restrictions, generally used in low-pressure, temperature pipe, especially for the water pipeline. General medium temperature between -20~120 degrees, the work pressure of less than 1.6Mpa, but diaphragm type check valve can do larger caliber, DN maximum can be more than 2000mm.
Ball check valve because the sealing part is covered with rubber ball, therefore, good sealing performance, reliable operation, anti water hammer performance; the seals can be a single ball, they can make more balls, so you can make large caliber. But its seal is wrapped in rubber hollow sphere, does not apply to high pressure pipeline, only applies to the middle and low pressure pipeline.Because the shell material of spherical check valve can be made of stainless steel, sealed hollow sphere parts can be coated PTFE plastics, can also be applied in the pipeline so general corrosive medium.The check valve in the working temperature between -101~150 DEG C, the nominal pressure is less than 4.0Mpa, nominal in the range of 200~1200mm
