Pipe Fittings For Air Conditioner, Refrigeration, Natural gas, Water, Heat-Exchangers, Oil. Pipe Fittings For Air Conditioner, Refrigeration, Natural gas, Water, Heat-Exchangers, Oil. Outside Diameter: 1/4"-4 1/8" The kinds of Pipe Fittings: Elbow, Tee, Union, Coupling. Standard: ANSI B16.22 Package: Plastic bag, then put into carton box.