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The characteristics and scope of valve connection are different.
Apr 20, 2018

1. threaded connection valve. This connection usually processes the inlet and outlet ends of the valve into tapered pipes or straight pipe threads, so that it can be connected to the threaded joints or pipelines of taper pipes. Due to the possibility of larger leakage channels, sealing channels, sealing tape or packing can be used to block these channels. If the body material can be welded, but the coefficient of expansion is very different, or the range of changing range of working temperature is larger, and the thread joint must be welded by honey.

The main thread of the valve is the valve nominal below 50mm. If the path size is too large, the installation and sealing of the connecting part is very difficult.

In order to facilitate installation and removal of threaded connection valves, pipe joints can be used at appropriate locations in the piping system. A valve with a nominal diameter of less than 50mm can be used as a pipe joint, and the thread of the sleeve joint connects the two parts of the connection.

The 2. flange is connected to the valve. Flanged valves are easy to install and remove. But the valve is heavier than the threaded connection, and the price is higher. Therefore, it is suitable for all kinds of pipeline connection with diameter and pressure. However, when the temperature is over 350 degrees, the bolts, gaskets and flanges are loosened, and the load of the bolt is obviously reduced, and the flange connection with large force may be leaked.

3. welding connection valve. This connection is applicable to all kinds of pressure and temperature, and is more reliable than flange connection when used in the condition of loading. However, the disassembly and reinstallation of the welded joints are difficult, so its use is limited to a long and reliable operation, or the use of conditions and high temperature. Such as thermal power station, nuclear power engineering, ethylene engineering pipeline.

Valves with a nominal diameter less than 50mm usually have a welding socket to carry on the pipe at the flat end. Due to the formation of gap between the socket and the pipe in the socket welding, it is possible to cause the gap to be corroded by some medium, and the vibration of the pipe will make the connection part fatigue. Therefore, the use of socket welding is limited.

When the nominal diameter is larger, the use conditions are carve and the temperature is high, the valve body often uses the groove to weld the welding seam. At the same time, the welding seam has the original requirement. It is necessary to select the skilled welder to complete this work.