Application characteristics of general equipment valves

1 Threaded connection valve. This type of connection is generally to process the inlet and outlet ends of the valve into a tapered pipe or straight pipe thread, which can be connected to a tapered pipe threaded joint or pipeline. Considering that this type of connection may have relatively large leakage channels, sealants, sealing tapes or fillers can be used to plug these channels. If the material of the valve body can be welded, but the coefficient of expansion differs greatly, or the range of the operating temperature is relatively large, the threaded connection part must be honey sealed. Threaded valves are mainly valves whose nominal diameter is below 50 mm. If the diameter size is too large, the installation and sealing of the joint is very difficult.

In order to better facilitate the installation and disassembly of the threaded valve, pipe joints can be used on the appropriate parts of the piping system. Valves with a nominal diameter of less than 50 mm can use pipe sockets as pipe joints, and the thread of the pipe socket connects the two connected parts together.

2Flange connection valve. The installation and disassembly of the valve connected with the vacuum valve flange is relatively convenient. However, it is heavier than the threaded valve, and the corresponding price is also more expensive. Therefore, it is more suitable for pipe connections of various diameters and pressures. However, when the temperature exceeds 350 degrees, considering that the bolts, gaskets and flanges become loose, the load of the bolts is obviously reduced, which may cause leakage to the flange connection with greater force.

3 Weld and connect the valve. This type of connection is more suitable for various pressures and temperatures, and is more reliable than flange connections when used under more severe conditions. However, it is more difficult to disassemble and re-install the valve connected by welding, so its use is limited to generally reliable operation for a long time, or places where the operating conditions are heavy and the temperature is high. Such as the pipelines of thermal power stations, nuclear power projects, and ethylene projects.