Post #10055

When we are using water, it is ok to depend on the thread itself being a sealing surface. But when it comes to gas lines or refrigerant lines, we use what's called a flare fitting. There's a tool that forces the end of the tubing to flare out and that's the sealing surface. note with these fittings the thread inside the nut is not tapered, its is a straight thread. Also note that for gas that is breathable like oxygen, the flare fittings use a normal right hand thread. But for gasses we should not breath like LP gas, argon (welding), CO2 (welding) the threads are left hand threads. The turn backwards to a normal nut and bolt. So if you find a thread that looks odd or screws together backwards let that be a warning that it could be a flammable gas or a poisonous gas line.