Plumbing Glossary
Your complete dictionary to understanding plumbing jargon, tools, and systems.
Aerator
A small mesh screen attached to the end of a faucet to mix air with the water flow, reducing splashing and water usage.
Auger
Also known as a plumbing snake, a flexible tool used to dislodge clogs in drains and pipes.
Backflow
The undesirable reversal of the flow of water or mixtures from their intended direction in a plumbing system.
Ball Valve
A valve that controls water flow using a hollow, perforated, pivoting ball. When open, the hole is inline with flow.
Black Water
Wastewater from toilets that contains fecal matter and urine, requiring specialized treatment.
Catch Basin
A reservoir or receptacle designed to catch surface water runoff or debris before it enters a drainage system.
Cleanout
An accessible opening in a drainage system used for the removal of obstructions and clearing clogs.
CPVC
Chlorinated Polyvinyl Chloride. A type of plastic pipe that can withstand high temperatures, often used for hot water lines.
Descaling
The process of removing hard water mineral deposits (scale) from pipes, water heaters, and fixtures.
Drain Snake
A flexible auger used to clear clogs in smaller drains like sinks and tubs.
Effluent
Liquid waste or sewage discharged into a river or the sea, or from a septic tank into a leach field.
Escutcheon
A decorative plate that covers the hole in a wall or floor where a pipe or plumbing fixture enters.
Flapper
The rubber seal at the bottom of a toilet tank that lifts to release water into the bowl during a flush.
Float Valve
A valve connected to a hollow ball (float) that controls the water level in a toilet tank.
French Drain
A trench filled with gravel or rock containing a perforated pipe that redirects surface water and groundwater away from an area.
Galvanized Pipe
Steel pipes coated with zinc to prevent rust. Commonly found in older homes, they eventually corrode from the inside out.
Gray Water
Relatively clean wastewater from baths, sinks, washing machines, and other kitchen appliances (excluding toilets).
Grease Trap
A plumbing device designed to intercept most greases and solids before they enter a wastewater disposal system.
Hard Water
Water that contains high levels of dissolved minerals, specifically calcium and magnesium, which can cause scale buildup.
Hose Bibb
An outdoor water faucet protruding from a building to which a garden hose can be attached.
Hydro Jetter
A specialized machine that uses high-pressure water to scour and clean the inside surfaces of plumbing pipes.
Invert
The lowest inside point of a horizontal pipe or sewer invert.
Knockout Plug
A removable piece of plastic or metal in a plumbing fixture or pipe that is removed to allow a connection.
Leach Field
A network of perforated pipes laid in underground gravel trenches that dissipate effluent from a septic tank.
Main Line
The primary pipe that supplies water to a building or carries wastewater away to the municipal sewer or septic system.
Manifold
A pipe fitting with several lateral outlets for connecting multiple branch pipes to a main water supply line.
O-Ring
A circular rubber ring used as a gasket to create a watertight seal in faucets and valves.
Overflow Tube
A vertical tube inside a toilet tank that directs excess water into the bowl to prevent the tank from overflowing.
P-Trap
A U-shaped section of pipe under a sink or drain that traps a small amount of water to prevent sewer gases from entering the home.
Plumber's Putty
A pliable, clay-like substance used to create watertight seals around faucets and drains.
Pressure Reducing Valve (PRV)
A valve installed on the main water line that reduces high incoming municipal water pressure to a safe level for the home.
Reamer
A tool used to remove burrs from the inside of a pipe after it has been cut.
Repipe
The process of completely replacing the water supply plumbing system in a home or building.
Rough-In
The stage of construction where plumbing lines are run through the wall studs and floor joists before walls are closed.
Septic Tank
An underground wastewater treatment structure commonly used in rural areas without centralized sewer systems.
Sump Pump
A pump installed in a basement or crawlspace pit (sump) that pumps accumulated groundwater away from the foundation.
Sweat Fitting
A method of joining copper pipes by heating the joint and applying solder.
Tailpiece
The section of pipe that connects the bottom of a sink drain to the P-trap.
Tankless Water Heater
A water heating system that instantly heats water as it flows through the device, rather than storing it in a tank.
Trap
A curved section of plumbing designed to hold water and prevent sewer gases from escaping into the building.
Valve
A device that regulates, directs, or controls the flow of water by opening, closing, or partially obstructing passageways.
Vent Stack
A vertical pipe projecting through the roof that allows sewer gases to escape and air to enter the plumbing system.
Water Softener
A filtration system that removes calcium and magnesium minerals from hard water through a process called ion exchange.
Wax Ring
A wax donut-shaped seal placed between the bottom of a toilet and the closet flange on the floor to prevent leaks.
Weep Hole
A small opening that allows water to drain from an assembly, such as at the base of a retaining wall or shower drain.