Aerator:
A device screwed into the end of a faucet spout that mixes air into flowing water, and controls flow to reduce splashing. It sometimes contains a baffle to reduce flow to 2.5 gpm.

Angle Stop:
A shutoff valve between the water pipes and a faucet. Its inlet connects to the water supply pipe in a wall, and its outlet angles up 90 degrees toward the faucet. These are usually used to shut off water to a fixture in case of an emergency repair rather than daily usage.

Anode Rod:
A sacrificial rod installed in a water heater that protects the tank from corrosion, helping to extend the life of the tank.

Back Flow Preventer:
A device to prevent water from traveling from one system back into any part of the main distribution system, usually by siphoning, esp. into a potable water supply. This is generally required for sprinkler systems, handheld showers, pullout faucet spouts, kitchen sprayers, etc.

Ballcock:
The fill valve that controls the flow of water from the water supply line into a gravity-operated toilet tank. It is controlled by a float mechanism that floats in the tank water. When the toilet is flushed, the float drops and opens the ballcock, releasing water into the tank and/or bowl. As the water in the tank is restored, the float rises and shuts off the ballcock when the tank is full.

Basket Strainer:
A basket-shaped strainer with holes and a slot that fits into a sink or shower drain to allow water to run out but to catch food or other objects before they can enter the sewage system and possibly clog the drain.

Bleed:
To drain a pipe, tube, or hose of excess air by opening a valve at the end or systematically removing the air by force or suction.

Check Valve:
A type of backflow preventer installed in a pipe run that allows water to flow in only one direction.

Cleanout Plug:
A plug in a trap or drain pipe that provides access for the purpose of clearing an obstruction.

Compression Valve:
A type of valve that is often used for water faucets. It is opened or closed by raising or lowering a horizontal disk by a threaded stem.

Dip Tube:
Tube inside the water heater that sends cold water to the bottom of the tank.

Discharge Tube:
Outlet tube that connects a disposer or sump pump to the drain line.

Diverter:
Valves which direct water to various outlets. They are used in showers, tubs, bidets, and sinks.

Escutcheon:
A decorative metal flange or trim shield beneath a faucet handle that covers the faucet stem and the hole in the fixture or wall.

Fixture:
In plumbing, the devices that provide a supply of water and/or its disposal, e.g. sinks, tubs, toilets.

Flapper Valve:
The part on the bottom of the toilet tank that opens to allow water to flow from the tank into the bowl.

Float Ball:
The floating ball connected to the ballcock inside the tank that rises or falls with changing water levels in the tank, and actuates or shuts off the ballcock as needed.

Floor Flange:
A fitting that connects a toilet to a floor drain.

Hose Bibb:
An outdoor faucet, also used to supply washing machines.

Lavatory (Lav):
A fixed bowl or basin with running water and drainage for washing. Also reffered to as a restroom or a bathroom.

O-Ring:
Round rubber washer used to create a watertight seal, chiefly around valve stems.

Packing Nut:
Nut that holds the stem of a faucet in position & holds the packing material.

Pop-Up Drain:
Type of drain assembly for lavatory and bath. When a lavatory lift rod or bath overflow plate lever is lifted, the pop-up drain closes so the lavatory or tub retains water.

Reducer:
A fitting that connects pipes of different sizes together.

Saddle Valve:
A valve mounted on a pipe run by a clamping device, or fitting that taps into the side of a pipe, used to make quick connection to an existing line to provide a water supply for a low-demand device.

Sleeve:
Pipe which is passed through a wall for the purpose of inserting another pipe through it.

Stack:
The vertical main in the drain, waste, and vent system, extending one or more stories.

Stop Valve:
The shutoff valve under sinks and toilets. Allows water supply to be cut off to one fixture without affecting the water supply to other fixtures.

T & P Valve:
Temperature & pressure relief valve. A safety device used to expel excess pressure or heat from inside a tank.

Tailpiece:
Section of pipe that runs between a fixture outlet and the trap.

Tail Pipe:
The pipe added below the jet assembly, in a weak well application.

Tank:
Fixture reservoir for flush water. On a conventional toilet, the ballcock, flush valve, and trip lever are installed in the tank. A tank lid closes the top tank opening.

Tee:
A T-shaped fitting with three openings used to create branch lines.

Trap:
Curved section of drain line that prevents sewer odors from escaping into the atmosphere. All fixtures that have drains must have a "P" trap installed. A toilet is the only plumbing fixture with an "S" trap.

Trip Lever:
Flush handle and actuating arm on a toilet tank. Also the lever that opens and closes the drain on the bathtub waste and overflow.

Waste & Overflow:
Drain assembly for a bathtub. The outlet at the top removes the overflow water during tub filling and the drain at the bottom removes wastewater when the tub is drained.