GI Pipe Welding

gi pipe welding electrode

gi pipe welding procedure pdf

Using "chill rings" might be a good idea. You can't really do too much about the inside if the pipe, but the adjacent zinc can to some extent migrate to the weld area.

On the outside, you can grind off the zinc for about 13mm away from the weld. This will diminish exposure to zinc fumes while welding. Afterward, paint the area with cold galvanizing compound. Or, more elaborately, you could spray-galvanize the joints.

Duplicate thread. Welding anything with zinc on it with electrodes is hazardous to the operative, as has been pointed out in these columns several times before.

So, either:

• Screw or flange GI pipes together,

or

• Use a substitute material that doesn't need something unfathomable to protect the inside of the joint after welding. How about polyethylene, polypropylene, ABS or PVC pipes? These weld perfectly well using externally-applied heat or proprietary solvents and standard sizes are available off-the-shelf for the sorts of diameters under consideration.

Don't know your service, but have you considered grooved connections?

AWS (American Welding Society) D1.1 has the requirement(s) for steel structures. ASTM has the testing requirements for steel. Of course, these are rigid American standards and may not ne applicable to your application.

You don't mention whether you are welding uphill, downhill, or circumferential. You didn't mention the environment, welder's qualifications, or certification(s).

A WPS (Welding Process Specification) addresses all of these issues.

I suspect these pipes would be screwed and our dear friend has lost the thread cutting kit.

Galvanised pipe welding. Perish the thought!