When installing the American standard plug valve, in order to prevent damage to the plug valve and ensure the full performance of the plug valve, the following four points should be paid attention to: 　　
1. Make sure the valve is open.  Heat the pipe first.  Transfer as much heat as possible from the pipe to the plug valve.  Avoid extending the heating time of the plug valve itself.

2. Use gauze or steel wire brush to remove the pipe and cutting parts to make the metal surface shiny.  It is recommended not to use steel wool.

3. First cut the pipe in the vertical direction, trim and remove burrs, and measure the pipe diameter.

4. Apply flux to the outside of the pipe and the inside of the welding cover. The flux must completely cover the welding surface.  Please use flux sparingly