DE Plumber key terms

A number that rates how much wastewater a fixture produces compared with a standard fixture, used to size drain pipes and vents so the system carries the expected load.

A number that estimates the likely peak demand a fixture places on the water supply system, accounting for how often it is used, used to size supply piping.

The measured depth of water held in a plumbing trap that blocks sewer gas from entering a building; it is lost through evaporation or siphonage if the trap is improperly vented.

A U-shaped fitting beneath or near a fixture that holds water to seal out sewer gas while allowing wastewater to pass through to the drain.

A vertical pipe that lets air into the drainage system and releases sewer gas above the roof, protecting trap seals from siphonage and allowing drains to flow smoothly.

A one-way valve installed on a vent line that admits air when a fixture drains and closes to keep sewer gas inside, often used where a full vent stack is impractical.

The pipe that connects one or more fixtures to a soil or waste stack, sized by the fixture units it serves and required to be vented.

The main vertical pipe that carries wastewater and sewage from fixtures down to the building drain, extending upward to connect with the vent system.

The lowest horizontal piping of a drainage system that receives waste from stacks and branches and carries it to the building sewer.

The pipe that carries sewage from the building drain to the public sewer or private disposal system, starting outside the building foundation.

A one-way valve installed on a drainage line that closes automatically to stop sewage from flowing backward into a building during a sewer backup.

An accessible fitting with a removable cap that lets a plumber rod or snake a drain line to clear blockages.

A banging or knocking noise and pressure surge caused when flowing water is stopped suddenly, often controlled with air chambers or arrestors.

A device containing a trapped air cushion that absorbs the pressure surge when a valve closes quickly, preventing banging and pipe damage.

A device that lowers incoming water pressure to a safe level for the building's piping and fixtures, protecting them from excessive stress.

The increase in water volume as it is heated in a closed system, which raises pressure and must be relieved by an expansion tank or relief valve.

A safety valve on a water heater that opens to release water if temperature or pressure inside the tank becomes dangerously high.

A valve or assembly that stops contaminated water from flowing backward into the potable water supply, protecting drinking water from pollution.

Any actual or potential link between the potable water supply and a source of contamination that could allow pollutants to enter drinking water.

The unobstructed vertical distance between a water supply outlet and the flood-level rim of a fixture, providing the strongest form of backflow protection.

The edge of a fixture over which water would overflow onto the floor, used as the reference point for setting air gaps and fixture outlet heights.

A vent pipe that also serves as a drain for fixtures on a floor above, allowed only under specific code conditions and sizing limits.

The total length of pipe measured along its centerline including all fittings and bends, used to determine drain slope and vent sizing.

The downward pitch of a horizontal drain pipe, usually expressed in inches per foot, that lets wastewater flow by gravity without clogging.

The plumbing code term for a toilet; a fixture that receives human waste and discharges it through a trap into the drainage system.

Water that is safe for drinking, cooking, and personal use because it meets health standards for contamination and quality.

Official authorization from the local authority to perform plumbing work, required before installation so the work can be inspected and approved.

The stage of construction when pipes, drains, and vents are installed inside walls and floors before fixtures and finished surfaces are put in place.

A required visit by a code official to examine plumbing work at set stages, such as rough-in and final, to confirm it meets code before it is covered or used.

A document issued by the local authority confirming a building or space may legally be occupied, typically issued after final plumbing inspections pass.

A safety procedure that isolates energy sources and applies locks and tags so equipment cannot be started while a worker is servicing it.

Gear such as gloves, safety glasses, respirators, and boots worn to protect a worker from hazards on the job site.

An area with limited entry and exit that is not designed for continuous occupancy and may contain hazardous gases or low oxygen, requiring special safety procedures.

A document that describes the hazards, safe handling, and emergency measures for a chemical product used on the job.

A written agreement that modifies the scope, price, or schedule of a construction contract after work has begun.

A list of incomplete or defective items identified near the end of a project that the contractor must correct before final payment and acceptance.

A contractor's formal offer to perform specified work at a stated price, based on plans, specifications, and estimated labor and material costs.

A percentage of each payment withheld by the owner until the project is substantially complete, protecting the owner against unfinished or defective work.

A legal claim against a property for unpaid work or materials, which a contractor or supplier can file to secure payment.