True the branch test must be welded out with the branch down. When you make a field weld, the weld/thread/sock-o-let can be anywhere on the pipe. It is common on pipelines for the weld to be on the side or top of the pipe from a ease of connection view. As for ruling, I work with an engineer. I am familiar with B31.5 and 31.8 along with DOT 192 and 195. If the approved construction drawings show the connection on the side, I get it put on the side.A lot of these connections are hot taps where the o-let is welded to the carrier pipe, the proper length of a nipple and flange is welded on the o-let and the whole shebang is NDT and hydro-tested. Sometimes the o-let, nipple and flange are prefabricated and all that is done is the o-let is welded to the carrier pipe, NDE and then hydro-tested. Some companies require a split tee where the forged fitting is welded to the pipe, tested and then tapped. These are used a lot in stopple situations where the line needs to be blocked off for installation of valves or replacement of pipe. Welders here must no only be multiple qualified, but pass API 1107. Another special breed of welder is one who welds on loaded lines. Nothing like having 450 psi of LPG or gasoline 0.375 inches away from a hot electrode.
BABRT's