Plumbing Glossary

A.

Angle Stop
A shut-off valve located under sinks or behind toilets that controls water flow to a specific fixture.

Anode Rod
A metal rod inside a water heater tank that helps prevent corrosion and extends the life of the unit.

Air Gap
A safety device that prevents contaminated water from flowing back into your clean water supply.

B.

Backflow
The unwanted reversal of water flow that can allow contaminated water to enter your clean water supply.

Ball Valve
A shut-off valve that uses a rotating ball to quickly control water flow.

Branch Line
A smaller pipe that connects to a main plumbing line and carries water to specific fixtures.

C.

Cleanout
An access point in your plumbing system that allows plumbers to clear blockages from drain lines.

Compression Fitting
A type of pipe connection that seals pipes together without soldering.

Cross Connection
A connection between clean water and wastewater systems that can cause contamination if not protected.

D.

Drain Trap (P-Trap)
The curved pipe beneath sinks that holds water to prevent sewer gases from entering your home.

Drain Line
A pipe that carries wastewater away from sinks, tubs, toilets, and appliances.

Diverter Valve
A valve that redirects water flow, commonly used in showers or tub spouts.

E.

Expansion Tank
A small tank installed near a water heater that absorbs pressure increases caused by heated water expansion.

F.

Fixture
Any plumbing device that uses water, such as sinks, toilets, showers, or faucets.

Flange
A pipe fitting that connects a toilet to the floor and the drain pipe beneath it.

G.

Galvanized Pipe
Steel pipe coated with zinc to prevent rust. Common in older homes and often replaced with modern piping.

Greywater
Wastewater from sinks, showers, and laundry that does not contain sewage.

H.

Hard Water
Water containing high levels of minerals like calcium and magnesium, which can cause buildup in pipes and fixtures.

M.

Main Water Line
The primary pipe that brings water from the municipal supply into your home.

P.

Pressure Regulator (PRV)
A device that controls incoming water pressure to protect your plumbing system.

PEX Piping
Flexible plastic piping commonly used in modern plumbing installations.

Plumbing Stack
The main vertical drain pipe that connects multiple drain lines to the sewer system.

S.

Sewer Line
The main underground pipe that carries wastewater from your home to the municipal sewer system.

Shut-Off Valve
A valve that stops water flow to a specific fixture or the entire home.

Sump Pump
A pump installed in a basement or crawlspace that removes excess groundwater to prevent flooding.

T.

Tankless Water Heater
A water heater that heats water on demand rather than storing it in a tank.

Thermostatic Mixing Valve
A valve that blends hot and cold water to maintain a consistent and safe temperature.

V.

Vent Pipe
A pipe that allows sewer gases to escape and helps maintain proper drain pressure.