OR Plumber key terms

The depth of water held in a plumbing fixture's trap, measured from the trap's weir to the lowest point of the dip, that blocks sewer gas from entering the building.

The top edge of the outlet side of a trap through which water must flow to drain away, setting the maximum water level the trap can hold.

The section of pipe between a fixture's trap and its connection to the branch or stack, which carries the fixture's waste and must be kept short to protect the trap seal.

A vertical pipe that extends above the building and provides air to the drainage system so traps keep their seals and wastewater flows freely.

The extension of a soil or waste stack above the highest fixture drain, which vents that stack and often the building sewer through the roof.

A vertical pipe that carries the discharge of water closets and other fixtures containing solid waste down through the building to the building drain.

A vertical pipe that conveys liquid waste from fixtures other than water closets, such as sinks and lavatories, down to the building drain.

A pipe that connects one or more individual fixtures to a soil, waste, or vent stack, serving as the local drain line for those fixtures.

The lowest horizontal pipe inside a building that collects waste from all stacks and branches and carries it to the building sewer.

The pipe that carries waste from the building drain, past the foundation, to the public sewer or private disposal system such as a septic tank.

An accessible opening with a removable cap or plug installed in a drainage line so that blockages can be cleared with a snake or auger.

An unobstructed vertical space between a water supply outlet and the flood level of a fixture or receptacle, providing the highest level of backflow protection.

The unwanted reversal of water flow in a piping system, which can pull contaminants from a fixture or cross-connection into the potable supply.

A device such as a reduced-pressure-zone assembly or double check valve that stops contaminated water from flowing backward into a potable water system.

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

The upper edge of a fixture or receptacle over which water would overflow onto the floor, used as a reference point for air gaps and backflow protection.

The pipe that brings potable water from the public main or private well to the building, ending at the water meter or main shutoff valve.

A device that measures the volume of water delivered to a building, typically installed on the service line and often serving as the utility's ownership point.

The primary valve that stops all water flow into a building's distribution system, used in emergencies and repairs.

A valve installed on a fixture supply line or branch that lets water be shut off locally for repair or replacement without draining the whole system.

A loud banging or knocking in pipes caused by a sudden change in water velocity when a valve closes quickly, producing a pressure surge that can damage fittings.

A device containing a trapped air chamber or piston that absorbs the pressure surge created when water flow stops abruptly, protecting piping from water hammer.

The increase in water volume as it is heated, which in a closed system can raise pressure and requires a means such as an expansion tank to relieve it.

A tank connected to a closed water heating system that accepts the extra volume created as water heats, keeping pressure within safe limits.

A safety device on a water heater or boiler that opens automatically to release pressure before it reaches a dangerous level.

A combined safety valve on a water heater that discharges water if either the temperature or the pressure inside the tank exceeds its set limit.

An appliance that heats and stores potable water for domestic use, typically including a tank, heating element or burner, thermostat, and safety valves.

A numerical value assigned to each plumbing fixture based on its probable rate of water use and waste discharge, used to size pipes and vents.

A unit of measure expressing the probable waste discharge load a fixture places on the drainage system, used when sizing drains and stacks.

A unit of measure expressing the probable demand a fixture places on the water distribution system, used to size supply piping.

The total measured length of pipe along its centerline, including all fittings and bends, used in sizing supply and drainage lines.

The drop in water pressure caused by resistance as water moves through pipe, fittings, and valves, which increases with flow rate and pipe length.

The pressure exerted by water at rest, determined by the height of the water column above the point of measurement, roughly 0.433 psi per foot of elevation.

A valve that lowers incoming water pressure to a safe, consistent level for the building's distribution system and fixtures.

A U-shaped fitting beneath a fixture that holds a water seal to block sewer gases while allowing waste to pass through.

A pipe or opening that lets air into the drainage system and allows sewer gases to escape above the roof, protecting trap seals and aiding flow.

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

A toilet fixture that receives human waste and discharges it through a trap to the drainage system, typically the largest single source of drainage load.

The set of plumbing regulations adopted by the state of Oregon, based on a model code with state amendments, governing installation and inspection of plumbing systems.

An official authorization issued by the local authority before plumbing work begins, ensuring the work will be inspected for code compliance.

A review of plumbing work by a code official at required stages, such as rough-in and final, to confirm compliance with the adopted code.

The stage of plumbing work completed before walls and floors are closed, when pipes, fittings, and supports are installed and ready for inspection.

A person who has met Oregon's training, examination, and experience requirements and holds a state license to perform plumbing work.

The open end of a vent pipe that extends above the roof, admitting air to the system and releasing gases safely outdoors.