Pipeline by hand is predominately downhand XX10 rods ran really hot! I worked in a few vessel shops. The better shops had welders weld and fitters and steel fabricators cut and fit pieces. The most valuable guys in the shop were the welders who were also good fitters and could fit there own pipe and read piping blueprints. I worked with a few of these guys and they made fitting look easy, it isn't.
I also worked in some oilfield shops. One in particular a guy thought he was the worlds greatest fitter because he could fit one piece at time in place to run piping for a mud tank. Another guy there who ran his own rig, was a really good fitter, and said the guy couldn't look at a piping blueprint with 4 pieces and fit them on a bench. I knew this to be so true having worked as an apprentice welder at one of the big vessel shops. They could look at the print and fit 90% of the pieces allowing for expansion and contraction to get the right finished length. Once in place only a few welds had to be done in position. The worlds greatest would have been totally lost. I was never fortunate enough to get to work a lot with fitters. I did do a lot of cutting of pieces and got pretty good with a torch though. People would comment on my cutting and then ask why I always cleaned the tip before I started. Duh! I worked for a cheap employer who didn't have a shape cutter and had to cut triangle hinges out of 3/8" and 1/2" flat bar using a cardboard template, tack 3 of them together, drill the hole and then grind them all the same. Grinding 1 1/2" thick steel isn't fun so I got pretty good at accurate cutting. Here's my tip when following a soapstone line, don't cut down the middle of the line or your piece will be too short. Cut on the outside or inside (when cutting a hole) of the line so you get the right size.