How Should The Galvanized Pipe Be Welded?

Galvanized pipes are corrosion-resistant, have a long service life, and are relatively cheap, so they are widely used. When welding galvanized pipes, we must pay attention to the correct welding method of galvanized pipes and some matters needing attention:

1. Before welding

The pre-welding preparation of galvanized steel is the same as that of ordinary low-carbon steel. The main thing is to deal with the groove size and the nearby galvanized layer. The groove size is generally 60-65°, leaving a certain gap, generally 1.5~2.5mm; before welding, in order to reduce the penetration of zinc into the weld, the galvanized layer in the slope door should be removed before welding.

2. When welding

The welding method adopts centralized beveling, without a blunt edge process for centralized control, and the two-layer welding process reduces the possibility of incomplete penetration. Pay attention to the following when welding:

(1) When welding the first layer of the weld seam in multi-layer welding, try to melt the zinc layer and make it vaporize, evaporate and escape the weld seam, which can greatly reduce the liquid zinc remaining in the weld seam.

(2) When welding the fillet weld, also try to melt the zinc layer on the first layer and make it vaporize and evaporate to escape the weld. The method is to move the end of the electrode forward about 5~7mm, and then return to the original position to continue welding forward after the zinc layer is melted.

(3) For horizontal welding and vertical welding, it is recommended to use short slag electrodes; the welding quality is better by adopting back-and-forth forward and backward transport technology.

3. After welding

After the galvanized pipe is welded, the galvanized layer at the weld must be polished off, otherwise, problems such as air bubbles, trachoma, and false welding will occur, the weld will become brittle and the rigidity will decrease.