Useful A-Z Plumbing Terms for Homeowners

There are many interconnected parts that work together to keep a modern home running. Understanding how everything works can be a real challenge and nowhere is this more apparent than with home plumbing. Sometimes it can be difficult to explain an issue to a professional plumber or order a part without knowing the terminology. In this article, we will explain some useful plumbing terms in alphabetical order and offer a brief description for each one.

A’s

Access Panel: This is a panel located in a wall or ceiling near a fixture, and it allows access to work on hidden electrical or plumbing systems.

Angle Stop: This a shutoff valve that’s located between the water supply and a plumbing fixture and it’s turned to shut off the flow of water for repairs.

Anode Rod: This is a rod that can be found inside the water heater, it’s used to protect the water tank from corrosion caused by aluminum or magnesium.

B’s

Backwater Valve: This is a critical valve that’s used to prevent a flow of disposed of sewage from coming back into the home.

Ball Check Valve: This valve is placed on a water line to ensure that the water can only flow in a single direction and it’s useful to prevent a backflow of water.

Ballcock: A ballcock is used to control how the water flows in a gravity operated toilet tank. When the toilet is flushed a float drops, and this is how the ballcock is opened. The water is distributed into the tank, and the water rises taking the float with it. Once the float has risen to the predetermined level, the ballcock is shut off automatically.

Branch: This is also known as a lateral line, and it’s a secondary part of a drain system.

Branch Vent: This is a vent that connects to a vent stack.

C’s

Check Valve: This is another type of backflow prevention measure, the check valve can be installed on a pipe to ensure that the water can only flow in one direction.

Cleanout Plug: This is a plug located in a drain trap or pipe, and it’s used to gain access to the drain line to clear clogs and blockages in the pipes.

Closet: This is a polite synonym for a toilet from the term “water closet” or “WC.”

Closet Augur: This is a flexible rod with a connected augur that’s used to access and remove hard to reach clogs in a toilet trap.

Closet Flange: This is the ring that’s used to anchor the toilet bend in place on the floor. A closet flange will also have closed bolts included to secure the toilet in place.

D’s

Diaphragm: This is a flexible membrane that is used to regulate water flow and any build up that occurs inside a valve.

Dip Tube: This supplies cold water to the bottom of your water heater tank.

Drip Leg: This is also referred to as a sediment trap, it’s a pipe installed in the lower part of a gas line, and it’s used to collect debris and condensation.

E’s

Escutcheon: This is a protective cover located under the faucet handle to hide the fixture hole.

F’s

Fall: This is also referred to as a pitch or flow, it’s a slope that’s required to ensure correct drainage in a pipe.

Fixture: This is any plumbing device that can provide water or facilitate disposal. The most common plumbing fixtures are found in areas such: sinks, showers, and toilets.

Flapper Valve: This valve connects the water tank and toilet bowl together; when it opens water can flow from the tank into the bowl.

Float Ball: This is a plastic ball that’s attached to the ballock, and the height of the water is determined by its placement.

Floor Flange: This is also referred to as a closet flange, and it’s used to connect a toilet to a sewer line.

G’s

Gas Cock: This is located on the main gas line, and it’s used to shut off the gas.

Gate Valve: This type of valve is used to control the flow of liquids inside pipes.

Gravity Operated Toilet: This toilet uses gravity for downward pressure inside a toilet tank to create a flush.

Gray Water: This is the waste water that originates from fixtures, and it doesn’t include water from the toilets.

H’s

Horizontal Branch: This runs from a plumbing fixture to connect to a waste stack.

Horizontal Run: This is the distance traveled by a liquid from an entry point to an exit in a pipe.

Hose Bib: This is a term for any common outdoor faucet.

M’s

Main Line: This is the main water supply that comes from the water company meter out at the street and into the plumbing pipes in and around your home.

N’s

Nipple: This is a short section of pipe that connects together various fittings.

P’s

Power Flush System: This is used to compress water in order to provide a pressurized flush, and it’s most often found in commercial plumbing applications.

Pressure Reducing Valve (PRV): This is a special valve found on the main water line, and it’s used to constrain the volume of water that enters from the main supply provided by the water company. It’s used to normalize the water pressure making it more suitable for use in your home.

R’s

Rim Holes: This is a series of small holes that found under the rim around the toilet bowl, and they are used to refill the bowl after a flush.

S’s

Saddle Valve: This valve is a clamping device that’s used to make a quick connection between lower demand plumbing devices.

Septic Tank: This is a sewage treatment system for homes that are not connected to a sewage pipe.

Straight Stop Valve: This valve is used to shut off the water supply for repairs.

Sump Pump: This sits in a pit, water accumulates there and then it’s pushed out of the home. This used primarily in basements that are prone to flooding.

Supply Line: This is a line that carries the water supplied from the main line into plumbing fixtures.

T’s

Temperature and Pressure Valve (T&P Valve): This is a relief valve used to release excess heat and pressure from a water tank.

Tailpiece: A pipe that runs from a fixture to a trap.

Trap: A curved drain line that stops sewer odors from coming into the home, most fixtures have a “P” trap except the toilet which has an “S” trap instead.

Trapway: This connects the toilet bowl to the waste outlet.

Trip Lever: The flush handle on the toilet tank.

V’s

Vent: A pipe that allows air into a drain system.

Vent Stack: A pipe that releases odors and gases outside the home.

W’s

Water Hammer: This is a loud noise and/or vibration caused by a sudden surge or halt of water in pipes.

By Giovanni Longo President Flood Brothers Plumbing
Giovanni Longo is a 3rd generation master plumber who has been practicing his craft and trade in the greater Los Angeles area for well over a decade and a half. A plumbing and hydraulics-engineering innovator, Giovanni’s particular world-class expertise focuses on dealing with challenging sewer system designs as well as resolving complex commercial and residential draining issues. As a certified Flood Mitigation expert, he is also well versed in a wide variety of water damage and remediation solution.