As stated, do not EVER use galvanized pipe as a chimney. The fumes it gives off will be poisonous. First you know of it is when you end up feeling like you have the flu. Hit me when I was a young guy, welding galvanized plate on a job.
Stove like that needs to be 3 feet from any combustible surface(this includes wood framing behind a wall sheathing that is noncombustible). You can cut that distance in half by installing a noncombustible shield with a 1” minimum air gap between the shield and the wall. Shield needs to be at least 1 inch off the floor and end three to four inches below the ceiling. It should extend 18 inches past the stove on both sides. If stove is in a corner, or within 3 feet of a sidewall, both walls must be shielded or have sufficient clear space from stove. Assume shop floor is concrete? If a flammable surface, more hoops to jump through.
