I've got to change some vents at the end of my steam mains. The vents are connected to 3/8" risers coming out of a 3/8" elbow coming out of a 1 1/2" main. I can't get the elbow or the risers (or the couplings on the risers) to budge. I've tried PB blaster and even tried heating one of the couplers with propane torch but still nothing will budge. any ideas?
