Check valve refers to the valve that automatically opens and closes the valve flap depending on the flow of the medium itself, and is used to prevent the medium from flowing back. It is also called check valve, one-way valve, reverse flow valve, and back pressure valve. The check valve is a kind of automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and the drive motor from reversing, and the discharge of the container medium.
1. In order to prevent the medium from flowing back, check valves should be installed on the equipment, devices and pipelines;
2. Check valves are generally suitable for clean media, not for media containing solid particles and high viscosity;
3. Generally, horizontal lift check valves should be used on horizontal pipes with a nominal diameter of 50mm;
4. The straight-through lift check valve can only be installed in horizontal pipelines;
5. For the inlet pipeline of the water pump, a bottom valve should be used. The bottom valve is generally only installed on the vertical pipeline at the inlet of the pump, and the medium flows from bottom to top;
6. Compared with the swing type, the lifting type has better sealing performance and greater 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, the nominal pressure can reach 42MPa, and the nominal diameter can also be large, and the larger can reach more than 2000mm. According to the different materials of the shell and the sealing parts, 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--800℃;
9. The applicable occasion for swing check valve 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;
