Welding connection refers to a connection form in which the valve body has a welding groove and is connected to the piping system by welding. The welding connection between valve and pipeline is divided into butt welding connection (BW) and socket welding connection (SW). Butt welding (BW) can be applied to various sizes, pressures and high temperature conditions. Socket welding connection (SW) is generally suitable for valves less than or equal to DN50.
2 Threaded connection
A simple connection method, often used for small valves.
There are two situations:
Direct sealing: the internal and external threads directly play a sealing role. In order to ensure that the joints do not leak, they are often filled with lead oil, thread hemp and PTFE tape. Among them, PTFE tape is widely used.
Indirect sealing: the force of screw tightening is transmitted to the gaskets on the two planes, so that the gasket plays a sealing role.