Plain definitions of 36 terms we use on the job in Kent.
Term Index
Open any term below for a dedicated definition page.
An aerator is a small screen fitted to the end of a faucet spout. The screen mixes air with the water stream and helps control splashing. A faucet aerator also catches small debris that may affect flow. It can be removed for cleaning or replacement during faucet repair.
An air gap is a plumbing fitting that prevents contaminated water from flowing backward into a clean water supply. In a kitchen, the fitting usually sits beside the faucet and connects to a dishwasher drain hose. Its open space breaks the drain connection, so wastewater cannot siphon back through the hose.
Anode Rod is a metal component inside a tank water heater that helps protect the steel tank from corrosion. The rod attracts corrosive elements in the water, so the rod wears away before the tank does. A plumber checks its condition during water heater repair and replaces it when the remaining material is too thin.
Also called: Sacrificial Anode
A Backflow Preventer is a plumbing device that stops contaminated water from moving backward into a clean water supply. It protects drinking water when pressure changes push water in the wrong direction. Different models serve homes, irrigation systems, boilers, and other connections that may expose supply lines to unsafe water.
Also called: Backflow Device
A cleanout is an access point in a drain or sewer pipe. A removable cap covers the opening when the line is in normal use. Plumbers remove the cap to inspect the pipe, clear a blockage, or flush the line. Cleanouts may sit indoors, outdoors, or near a building’s sewer connection.
Also called: Cleanout Plug
A compression fitting is a plumbing connector that joins pipe or tubing without soldering or threaded bonding. The fitting uses a nut and compression ring to press against the pipe. This pressure forms a seal around the connection. Compression fittings are common in water line repairs where access is limited.
A drain auger is a flexible cable tool that clears clogs inside drain pipes. The cable moves through the pipe and breaks apart or pulls back soft blockages, such as hair or buildup. A hand crank or motor turns the cable, while the attached tip reaches material that water pressure alone may not remove.
Also called: Plumbing Snake
A Drain Trap is a curved section of drain pipe that holds a small amount of water beneath a fixture. That water blocks sewer gases from entering the room through the drain. Drain traps also collect some debris, which can affect drainage and may need cleaning during drain service.
An expansion tank is a small vessel connected to a water heater that absorbs pressure from heated water. Its internal air cushion gives the water room to expand. This helps limit pressure changes in a closed plumbing system and can reduce stress on pipes, fittings, valves, and the water heater.
Also called: Thermal Expansion Tank
A flapper valve is the rubber or plastic seal inside a toilet tank that controls water leaving the tank. It lifts when you flush and closes as the tank refills. A worn, warped, or poorly seated flapper valve can let water leak into the bowl and cause repeated refilling.
Also called: Toilet Flapper
A float switch is a water-level control that starts or stops equipment as a float rises or falls. In a sump pump system, the switch senses water in the pit and signals the pump to remove it. The switch may hang from a cord or move along a fixed rod.
A Garbage Disposal Baffle is a flexible rubber guard fitted at the top opening of a garbage disposal. The baffle helps limit splashing, reduces noise, and keeps larger objects from entering the grinding chamber too quickly. Water and small food particles can pass through its openings during normal disposal use.
Also called: Splash Guard
Hydrostatic Testing is a plumbing inspection method that uses water pressure to check whether a pipe system holds pressure without leaking. A technician isolates the section, fills it with water, and watches the pressure reading. In sewer line work, the test helps show whether buried piping may have leaks, breaks, or open connections.
Also called: Pressure Testing
A leak sensor is a small device that detects unwanted water and sends an alert when moisture reaches its sensing area. You can place one near a water heater, washing machine, sink, or other plumbing fixture. A leak sensor helps reveal a developing water problem before visible damage spreads.
Also called: Water Leak Alarm
A main shutoff valve is the control that stops water from entering a building through the main water line. You can close the valve during a leak, plumbing repair, or water line replacement. The valve is usually near where the water service line enters the home, though its exact location can vary.
Also called: Main Water Shutoff
A manifold is a plumbing distribution fitting that sends water from one supply line to several branch lines. Each branch serves a fixture or area, such as a bathroom, kitchen, or laundry room. Shutoff points on the manifold can isolate one branch while the rest of the home keeps receiving water.
Also called: Plumbing Manifold
A P-Trap is a curved drain fitting that holds a small amount of water beneath a sink, tub, shower, or other fixture. The water blocks sewer gases from entering the room. The trap also provides a reachable section of pipe where debris may collect and where drain cleaning work can begin.
Also called: U-Bend
Pipe Bursting is a trenchless sewer repair method that breaks an old buried pipe while pulling a new pipe through the same path. The process needs small access pits at selected points. It can replace damaged sewer lines while limiting surface digging across areas such as driveways, yards, or walkways.
Also called: Pipe Splitting
Pipe lining is a trenchless sewer repair method that creates a new inner surface inside a damaged pipe. A flexible liner coated with resin goes through the existing pipe and is shaped against its walls. The resin hardens in place, sealing cracks and restoring flow without removing the full pipe from the ground.
Also called: Cured-In-Place Pipe
A pipe sleeve is a protective tube or opening placed around a pipe where it passes through concrete, soil, framing, or another material. The sleeve creates space around the pipe and helps protect it from rubbing, movement, moisture contact, or damage during construction and later repairs.
A Pressure Balancing Valve is a shower control that keeps water temperature steadier when hot or cold water pressure changes. The valve adjusts the flow from each supply line as pressure shifts. This helps reduce sudden temperature changes when another fixture uses water during a shower.
Also called: Pressure Balance Valve
A Pressure Reducing Valve is a plumbing control that lowers high incoming water pressure to a safer level for a building’s pipes and fixtures. The valve uses a spring and diaphragm to adjust water flow as pressure changes. It helps limit stress on supply lines, faucets, toilets, and water heaters.
Also called: Pressure Regulator
A pressure switch is an electrical control that starts or stops equipment when fluid pressure reaches a set point. The switch senses pressure through a diaphragm or similar part, then opens or closes its electrical contacts. Plumbing systems may use pressure switches with pumps, tanks, or controls that depend on steady pressure.
Root Intrusion is a sewer pipe problem in which tree or shrub roots enter through cracks, loose joints, or small openings. Inside the line, roots grow and form a tangled mass that catches waste and slows flow. The blockage can lead to backups, leaks, or pipe damage if the opening remains untreated.
Also called: Tree Root Intrusion
A Sewer Camera is a flexible inspection tool with a small camera on its end. A plumber guides the camera through a sewer pipe and views the live image on a monitor. The inspection can show blockages, cracks, root intrusion, separated joints, or other conditions inside the pipe.
Also called: Inspection Camera
Sewer Lateral is the underground pipe that carries wastewater from a building's plumbing to a public sewer main or private treatment system. The property owner usually controls the section on the property, while public agencies may control the connection near the street. A lateral can include buried pipe, cleanouts, and connection points.
Also called: Lateral Sewer Line
A sewer pipe is a buried or exposed pipe that carries wastewater from a building to a public sewer or private treatment system. Sewer pipes connect household drains to the sewer line. They rely on gravity or pumping to move wastewater, and they must keep joints sealed to prevent leaks, soil entry, and blockages.
Also called: Sanitary Sewer Pipe
A supply line is a flexible or rigid tube that carries clean water from a shutoff valve to a plumbing fixture. In toilet installation, it connects the toilet tank to the valve in the wall or floor. The line must fit both connections and allow water to reach the fixture without leaking.
Also called: Water Supply Line
A tankless water heater is a water-heating appliance that warms water only when a fixture calls for hot water. It has no storage tank. Cold water passes through a heat exchanger, where gas burners or electric elements raise the water temperature before it reaches a faucet, shower, or other outlet.
Also called: On-Demand Water Heater
A Thermostatic Mixing Valve is a temperature-control device that blends hot and cold water before water reaches a fixture. The valve senses the mixed water temperature and adjusts the flow when conditions change. This helps a water heater supply hot water while the tap receives a steadier, controlled temperature.
Also called: TMV
A toilet flange is a fitting that connects a toilet to the drainpipe and anchors it to the floor. The flange sits at the drain opening beneath the toilet. It has holes for mounting bolts and a surface that supports a wax ring or another toilet seal.
Also called: Closet Flange
A Trap Primer is a plumbing device that adds water to a drain trap when the trap may dry out. The added water helps maintain the trap seal, which blocks sewer gases from entering a building. Trap primers commonly serve floor drains in areas that receive little regular water flow.
A Vacuum Breaker is a backflow prevention device that stops contaminated water from being pulled into a clean water supply. The device admits air when water pressure drops or flow reverses. Vacuum breakers commonly protect hose connections, irrigation lines, boilers, and other outlets where backsiphonage could affect drinking water.
Also called: Atmospheric Vacuum Breaker
Water Hammer is a pressure surge that occurs when moving water stops or changes direction quickly inside a pipe. The sudden force can make pipes bang, shake, or vibrate. The noise often happens when a faucet, valve, washing machine, or dishwasher shuts off and interrupts the water flow.
Also called: Hydraulic Shock
Water Softener Resin is a group of small beads inside a water softener tank that removes hardness minerals from water. The beads attract calcium and magnesium as water passes through the tank. A salt solution later cleans the beads so they can continue treating water. Resin condition affects softener performance.
Also called: Resin Beads
A Wax Ring is a soft sealing gasket that fits between a toilet and the drain flange. It closes the joint around the toilet outlet, helping keep wastewater and sewer gases inside the drain system. The ring compresses when the toilet rests on it, creating a watertight seal without threaded connections or glue.
Also called: Toilet Seal
