What Is a Black Red Plumbing Coupling?

Black Pipe

• Black pipe gets its name from its color. A type of steel pipe, black pipe exhibits high temperature resistance and corrosion resistance. These qualities help define the applications in which plumbers most frequently use it. Black pipe appears commonly in gas systems and in other heating and cooling operations that require the transportation of very hot things, such as steam. Manufacturers also make black pipe for transporting oil and water, since it resists rusting. The exact temperature and pressure ratings of black pipe depends on the intended purpose of the pipe.

Couplings

• Couplings comprise one of the many plumbing fittings. Fittings join two pieces of pipe together. Numerous types of fittings exist, including elbows, crosses, unions, tees and double tees. A coupling entails a straight piece of pipe with threaded openings on either end. By screwing the end of threaded pipes into either side of the coupling, plumbers join two pipes or pipe systems. The word “coupling” sometimes appears erroneously in reference to any type of fitting, though only straight fittings with two opposite threaded openings technically constitute couplings.

Reduction Fitting

• A reduction fitting is any pipe fitting that accommodates two different-sized pipes. Plumbers use reduction fittings at junctures where two different-sized pipes come together and the system requires some kind of transition between the two. Reduction fittings exist to accommodate all types of fittings, so they can fit anywhere within a plumbing system -- you can buy reduction elbows, reduction crosses, reduction tees and more. The term “reduction fitting” often appears in its abbreviated form, “red fitting,” in both written and spoken language.

Black Red Coupling

• A black red plumbing coupling is a black pipe reducing coupling. Or, a black steel coupling used to join two different-sized pipes. Black red couplings may appear in all of the plumbing systems -- gas, oil, water, steam, HVAC -- suited for black pipes. Numerous types of black red couplings exist, each differentiated by the size of openings at either end. Manufacturers produce these fittings in a number of sizes to accommodate for all the possible sizes of pipes a plumber may need to join in a system.