Glossary

Adaptor
A fitting that either provides a way to change the size of the pipe (reducing coupling), or that provides a way to change the type of pipe.

Appliance
In plumbing, a device that uses water and attaches to the plumbing and uses an external source of power, such as a dishwasher, washing machine, or water heater. Also see fixture.

Bend
see Ell

Bibb
See hose bibb

Boiler drain
A stop valve similar to a hose bibb, but with a male thread (outside, or exposed, thread)

Cap
A fitting with only one hole that fits over the end of a pipe to close it off. Also see plug

Cleanout
A fitting that attaches to a pipe that has a threaded plug (or cap) that can be removed for cleaning purposes.

Coupling
A fitting with two holes that permanently joins together two pipes.

Ell
Also called elbow, a fitting with two openings and a bend between, for changing direction in pipes. A right-angle ell is called a 90-ell, and a 45-degree ell is called a 45-ell. In DWV plumbing, 90-ell is also called a quarter bend, and a 45-degree ell is similarly called an eighth-bend. There are also a 60-degree fitting called a sixth-bend and a 22.5-degree fitting called a sixteenth-bend.

Fixture
Any plumbing device that uses water for a specific purpose but has no powered parts, such as a toilet, lavatory, tub, shower, or sink. Also see appliance.

Flange
A fitting that features a flat part so that it can be fastened down with screws or nails

Flood rim level
The level at which a fixture, when filled with water, will overflow.

Flux
A paste or thick liquid that is applied to metal before soldering, and which etches the surface of the metal and helps the solder to flow and adhere to the metal.

Frost proof valve
A hose bibb that features a long stem, so that the valve is inside the house while the handle is outside the house, and so that any water remaining on the outside of the valve automatically drains out whenever the valve is shut.

Gate valve
A valve that opens and closes by moving a solid piece of metal that fits tightly against machined surfaces.

Hose bibb
A stop valve with a female thread (inside thread), and with a flange for mounting with screws.

Lavatory
A bathroom sink. Also sometimes used for the bathroom itself. It is NOT a toilet.

Leader
A downspout from guttering

Nipple
A short piece of threaded pipe.

Plug
A fitting that fits inside the end of a pipe to close it off.

Soil
The waste from a toilet.

Solder
A mixture of soft metals that melts at a low-enough temperature that it can be used to provide a seal by adhering to harder metals.

Stop
A type of valve that closes off by means of a rubber washer that provides a seal under compression.

Supply
A tube that carries a fresh water supply from a stop valve to a faucet or other plumbing fixture.

Tee
A plumbing fitting with three openings, so that three pipes may be fitted together.

Trap
A compound bend in a pipe that provides a low point where water stays to provide an air seal

Union
A fitting that joins together the ends of two pipes, which features two parts that fit together with a threaded collar to clamp the ends together. The union enables the pipes to be tightly joined but also makes it easy to take them apart when necessary.

Vent
A pipe for connecting waste/drain plumbing systems with the outside air.

Waste
Drainage from plumbing fixtures.