IN Plumber key terms

A person who holds a state-issued license to perform plumbing work for a licensed plumbing contractor, having completed the required work experience and passed the licensing examination.

A licensed individual or business authorized to contract for plumbing installations, obtain permits, and supervise plumbing work, and who is responsible for code compliance on the jobs performed.

Written approval from the local authority allowing specified plumbing work to begin; the completed work must be inspected and approved before it is covered or placed in use.

The official or agency that enforces the plumbing code in a community, with power to interpret rules, approve materials and methods, and inspect installations.

A numerical drainage load assigned to a fixture based on its probable discharge, with one unit equal to about one cubic foot per minute, used to size drainage and vent piping.

The lowest piping of a building's drainage system, receiving soil and waste from stacks and branches and carrying it to the building sewer at or near the building wall.

The pipe that carries sewage from the end of the building drain to a public sewer, private sewage disposal system, or other approved point of disposal.

The measured length along the centerline of a pipe run, including all offsets, bends, and fittings, used to size piping and to limit vent and trap arm distances.

The pipe that brings water from the public main or a private source into the building, ending where the building water distribution system begins.

A valve that automatically lowers incoming water pressure to a set lower level downstream, protecting fixtures, appliances, and piping from excessive pressure.

A device containing a trapped air chamber or piston that absorbs the shock wave produced when water flow stops suddenly, quieting noise and preventing pipe damage.

The pressure remaining at a fixture or outlet while water is flowing, used to confirm the system can deliver adequate flow at the farthest or highest point.

The downward pitch of a horizontal drainage pipe, expressed as inches of fall per foot of run, that keeps wastewater moving fast enough to carry solids.

An accessible fitting with a removable plug or cover installed in drainage piping so a drain auger or cable can be inserted to clear a stoppage.

A one-way valve in a drainage line that closes when flow reverses, keeping sewage from a surcharged public sewer from backing up into the building.

A vertical drainage pipe that receives the discharge of water closets and similar fixtures, as distinguished from a waste stack that carries other liquid wastes.

A vertical pipe that supplies air to the drainage system so internal pressure stays near atmospheric, protecting trap seals from siphonage and back pressure.

A vent pipe that connects one fixture's trap arm to a vent stack or other approved vent, protecting that single trap from pressure changes.

One vent pipe that serves a group of fixtures connected to a common horizontal branch, relieving pressure in that branch so each fixture trap stays sealed.

A mechanical one-way valve that opens to admit air into drainage piping when pressure drops and closes tightly when flow stops, keeping sewer gas inside the system.

A fitting or assembly that holds a water seal to block sewer gas from entering a building while letting wastewater flow through, and that is self-scouring under normal use.

The water held in a trap between the crown weir and the dip tube that forms the barrier against sewer gas, typically two to four inches deep.

The section of pipe between a trap's weir and its connection to the drainage system, limited in length and fall so the trap seal is not siphoned out.

A tank or receptacle that slows wastewater so fats, oils, and grease separate and float while solids settle, keeping them out of the building sewer.

A receptacle or device that receives water or waste and discharges it to the drainage system, such as a sink, water closet, bathtub, or floor drain.

A fixture that receives human waste and flushes it into the drainage system using a gravity tank, flushometer valve, or other approved flushing device.

A floor-level receptor with a strainer that catches surface water and directs it into a trapped drainage connection, protecting the floor from standing water.

A fitting screwed onto a faucet spout that mixes air with the water to reduce splashing and flow rate while producing a soft, full stream.

A safety valve on a water heater that opens automatically when internal temperature or pressure exceeds its setting, releasing water or steam to prevent tank rupture.

A closed, air-charged tank connected to the water heating system that absorbs the extra volume created as water heats and expands, limiting pressure rise.

A mixing valve that blends hot and cold water to deliver a controlled, lower temperature at fixtures to reduce the risk of scalding.

A watertight pan placed under a water heater to catch leaks or relief valve discharge and route the water to an approved drain or safe location.

A fitting set at a low point in a roof that collects rainwater and leads it into storm drainage piping, often equipped with a strainer and sump.

A vertical rainwater pipe, also called a downspout, that carries water from a roof drain or gutter down to the storm drainage system or to grade.

A pipe system, public or private, that carries rainwater and surface runoff to a point of discharge, separate from sanitary sewage.

The unobstructed vertical space between a water supply outlet and the flood level rim of the fixture it serves, the most dependable protection against backflow.

Any actual or potential link between potable water piping and a source of contamination, such as a hose submerged in a sink or a boiler feed line.

A testable backflow preventer with two check valves and a relief valve that opens when pressure between the checks reverses, protecting against both backpressure and backsiphonage.

Backflow caused by negative pressure in the supply piping, which pulls contaminated liquid through a cross-connection into the potable water system.