Tuesday, February 21, 2012
More on Plumbing - Connecting the Torch - Teflon Tape vs Dope
Here's a picture of a torch - after correct installation.
This is a Nortel Minor Burner. The black hose is the gas, and the green hose is oxygen. Both are using "B" fittings. Notice the dope - white, on the gas, and the orange T-tape - teflon tape - on the oxygen.
Notice also the gas fittings have notches cut into the outside. Gas fittings are threaded to screw on in the opposite direction from usual (so lefty - tighty instead). This is so you don't attach a flammable gas line to a breathable gas line by mistake. You literally can't do it.
It takes two wrenches to undo and tighten the fittings - otherwise the torch just gets bent out of shape. The plumbing inside the torch is easy to bend once you start going at it with a wrench - and you don't want to do that. You notice the plate on the side marked "plate to stablize fittings" on the illustration above? If you have an older torch, and do not have these, but are planning to convert your torch from the barb fittings to the B fittings, contact firstname.lastname@example.org to obtain these plates. They just bolt on and stabilize the connectors so that you don't bend them while taking the fittings off.
Below, marked by the yellow arrows, is the adapter, and in hot pink, is the B fitting. Notice there is no dope or tape between these two. B fittings do not require tape and should seal tightly without it. If they don't - generally - there is some contamination or the fitting is damaged. It was the presence of a sealant in this area - between the pink and yellow - that clued us in that there was something wrong (see last post.).