Glossary of Plumbing Terms and Definitions

Planning to hire a plumbing contractor in the near future? Learning key plumbing industry terms and definitions will help you navigate your way through your experience from beginning to end.

access panel
An opening in the ceiling or wall near a plumbing fixture that allows plumbers to service the plumbing system or pipes.

Also known as: plumbing access panel, plumbing access

aerator
A device added to the open end of a faucet that mixes air with water. Aerating the water creates a more even flow. Faucet aerators are inexpensive to install and can help conserve water and make shower and faucet spray seem more full.

Also known as: low-flow aerators, aerator shower heads, aerating faucets, faucet aerators

backflow preventer
A device that stops wastewater and dangerous contaminants from flowing back into the drinkable water supply. Backflow preventers are often code requirements for sprinkler systems, hand-held showers, faucets with pullout spouts and kitchen sink sprayers.

Also known as: wastewater backflow preventer, backflow prevention valve

bathroom plumbing
Fixtures, toilets, sinks, showers and piping that are found in the bathroom

Also known as: bathroom fixtures, bathroom plumbing repair, shower plumbing, toilet plumbing repairs

commercial plumbing
Any plumbing repairs or installations that take place in a commercial building. Commercial plumbing is different than residential plumbing because it often deals with commercial-sized water heaters, boilers, larger piping and more involved plumbing systems. Some plumbing contractors specialize in commercial plumbing while others focus on residential plumbing.

Also known as: commercial building plumbing services, industrial plumbing, multi-tenant building plumbing, store plumbing, shopping center plumbing

coupling
A fitting that connects two pieces of pipe. Common couplings for piping and plumbing include elbow fittings, tee fittings, cap couplings, plug fittings, nipple couplings, barb fittings and pipe reducer couplings. Plumbing system fittings can include closet flange couplings, trap primer couplings, clean-out fittings, combo-tee fittings, sanitary tee and double sanitary tee couplings, and wye fittings.

Also known as: pipe couplings, couplings, fittings, pipe valves, PVC couplings, CPVC couplings

drain cleaning
A method of clearing organic debris and other materials from drains and pipes. Drain cleaning for residential structures and commercial buildings includes drain pressure washing, drain snaking, drain cleaning chemicals, clearing clogged drains, drain tree root clearing, and pipe degreasing.

Also known as: clog removal, degreasing, pipe cleaning, drain clearing, unclogging, clean drainage pipes

elbow
A pipe fitting that has two openings and changes the direction of the plumbing line. Pipe elbows come in a variety of degrees to account for the various angles of piping.

Also known as: el fitting, ell coupling, pipe elbow, plumbing elbow, plumbing ell

fittings
These usually refer to faucets, shower valves and tub fillers, but they may also refer to elbow fittings, tee fittings and flange fittings.

Also known as: plumbing fitting, fitting, pipe coupling

fixtures
In plumbing, fixtures are the objects that water comes from. Plumbing fixtures include water spigots and faucets, shower, sinks, toilets, urinals, and external plumbing system fixtures.

Also known as: fixtures, faucets, kitchen fixtures, bathroom fixtures, plumbing fixtures

GPM
“Gallons per minute” refers to the rate of water flow from faucets and shower heads. GPM flow is regulated by the federal government. New showerhead flow rates can’t exceed 2.5 GMP and new faucet flow rates can’t exceed 2.5 GPM or 2.2 GPM, depending on the pressure. Installing low-flow faucets and fixtures can result in water savings between 25 and 60 percent without a noticeable change in water pressure.

Also known as: gallons per minute, flow rate

GPF
“Gallons per flush” is the amount of water a toilet uses per flush. The current law requires a maximum of 1.6 GPF (older styles were usually 3.5 GPF).

Also known as: gallons per flush, flush flow rate, flush capacity

ID
Stands for “inside diameter,” which refers to the size of the diameter of a plumbing pipe when measured from the inside edges. All pipes are referred to according to their ID.

Also known as: inside diameter

kitchen plumbing
Sinks, faucets, dishwashers, garbage disposals, drains, S-traps, slip joints and supply line water pipes that are found in the kitchen

Also known as: kitchen fixtures, kitchen pipes, kitchen plumbing repair, kitchen plumbing installation

new plumbing installation
Refers to the installation of new plumbing lines, water pipes, drain lines, faucets and plumbing fixtures. New plumbing may be installed in new construction projects or in existing homes.

Also known as: plumbing installation, commercial plumbing installation, residential plumbing installation, industrial plumbing installation, plumbing replacement, plumbing reinstallation

OD
“Outside diameter” refers to the dimension commonly used to size water pipes and tubing for plumbing.

Also known as: outside diameter

PVC pipes
Polyvinyl chloride (PVC) is a hard white or cream-colored plastic that’s used to form plumbing pipes. PVC pipes are often used in venting and waste water systems that are not pressurized. PVC will melt if exposed to hot temperatures, so PVC pipes are used for cold water distribution.

Also known as: polyvinyl chloride, PVC piping

rooter service
A drain cleaning service that unclogs pipes, cuts tree roots out of sewer lines and clears home piping to allow for better plumbing drainage.

Also known as: plumber’s snake, drain snaking, drain rootering, drain rooting, pipe rooter service, pipe snaking

rough-in
The initial part of a plumbing installation that lays out all the basic plumbing lines without permanently connecting them. The rough-in generally includes water supply lines, water drains, water waste and vent lines that run to each fixture (toilet, sink, shower, etc.). It’s usually done before the plumbing inspection.

Also known as: roughing in, to rough in, roughing

toilet repair
Some toilet repairs can be simple enough for homeowners to handle themselves, or they may require the assistance of a plumber. The most common toilet repairs include a toilet running continuously, a loose or sticking toilet handle, water on the floor around the toilet, leaking toilet tanks, poorly flushing toilets, clogged toilets, noisy toilets and toilet tank repairs.

Also known as: toilet problems, toilet problem repairs, toilet part replacement, toilet tank repairs, toilet unclogging, fixing the toilet

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