1. In order to prevent the medium from flowing back, non-slam check valves should be installed on the equipment, devices and pipelines;
2. Non-slam check valves are generally suitable for clean media, not for media containing solid particles and high viscosity;
3. Generally, vertical lift check valves should be used on horizontal pipes with a nominal diameter of 50mm;
4. The straight-through lift check valve can be installed on both horizontal and vertical pipelines;
5. For the water pump inlet pipeline, a bottom valve should be used. The bottom valve is generally only installed on the vertical pipeline at the pump inlet, and the medium flows from bottom to top;
6. The lifting type swing type has good sealing performance and large fluid resistance. The horizontal type should be installed on the horizontal pipeline, and the vertical type on the vertical pipeline;
7. The installation position of the swing check valve is not restricted. It can be installed on a horizontal, vertical or inclined pipeline. If installed on a vertical pipeline, the flow direction of the medium should be from bottom to top;
8. The swing check valve should not be made into a small-diameter valve, it can be made into a high working pressure. According to the material of the shell and the seal, it can be applied to any working medium and any working temperature range. The medium is water, steam, gas, corrosive medium, oil, medicine, etc. The working temperature range of the medium is between -196 to 800鈩;
9. The applicable occasion is low pressure and large diameter, and the installation occasion is restricted;
10. The installation position of the butterfly check valve is not restricted. It can be installed on a horizontal pipeline, or on a vertical or inclined pipeline;
11. Diaphragm check valve is suitable for pipelines that are prone to water hammer. The diaphragm can well eliminate the water hammer caused by the backflow of the medium. It is generally used on low-pressure and normal temperature pipelines, and is especially suitable for tap water pipelines. Normal media work The temperature is between -12-120鈩 and the working pressure is less than 1.6MPa, but the diaphragm check valve can achieve a larger diameter;
12. The spherical check valve is suitable for medium and low pressure pipelines and can be made into a large diameter;
13. The shell material of the spherical check valve can be made of stainless steel, and the hollow sphere of the seal can be wrapped with polytetrafluoroethylene engineering plastics, so it can also be applied to the pipeline of general corrosive media, and the working temperature is -101 to 150 鈩;
14. When selecting a check valve for incompressible fluids, first evaluate the required closing speed, and the second step is to select the type of non-slam check valve that may meet the required closing speed;
15. The check valve for compressible fluid can be selected according to the similar method of check valve for incompressible fluid. If the medium flow range is large, the check valve for compressible fluid can be used with a deceleration device. If the medium flow is stopped and started quickly and continuously, such as the outlet of the compressor, a lift check valve is used.
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