ICC P1 key terms

Accepted by the code official as meeting the requirements of the adopted plumbing code, usually through listing by an approved agency or by a documented engineering evaluation.

The officer or authorized representative appointed by the jurisdiction to enforce the plumbing code, including reviewing plans, issuing permits, and inspecting work for compliance.

A change, addition, or modification to an existing plumbing system that affects its layout, capacity, or function, such as replacing pipe or relocating a fixture.

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

A device attached to a plumbing fixture that controls or directs the water supply, such as a faucet, flush valve, or shower valve.

The edge of a fixture or receptor from which water would overflow onto the floor, used to establish the required air gap or backflow protection height.

A dimensionless value assigned to a fixture based on its probable peak discharge rate and drain time, used to size drainage and water supply piping.

An appliance that heats potable water for domestic use and stores it for distribution, including the tank, controls, and connected safety devices.

A combined safety device that opens automatically when either the temperature or pressure inside a water heater exceeds its set limit, discharging water to a safe location.

A closed vessel with a compressed air charge that absorbs the increased volume of water as it is heated, limiting pressure rise in a closed potable water system.

Water that is free of harmful contaminants and safe for human consumption, cooking, and personal hygiene, meeting the quality requirements of the code.

The reverse flow of water or other liquids, gases, or substances into the potable water distribution system from any unintended source or direction.

Any actual or potential connection between the potable water system and a source of contamination or pollution that could allow backflow into potable water.

An assembly or device, such as a reduced-pressure principle assembly or double check valve, installed to prevent backflow from reversing into the potable water supply.

The unobstructed vertical distance between the lowest outlet of a water supply pipe and the flood level rim of the receiving fixture or vessel.

A backflow prevention device that admits air into a piping system to break a vacuum, preventing backsiphonage of contaminated liquid into the potable water supply.

The pipe that carries potable water from the water main or source of supply to the building, ending at the first shutoff valve inside the building.

The lowest piping of a drainage system that receives waste from inside the building and conveys it to the building sewer, usually at or below the lowest floor.

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

A vertical pipe that carries the discharge of water closets and other fixtures containing fecal matter from upper levels down to the building drain.

A pipe that conveys liquid waste from fixtures that does not contain fecal matter, such as from sinks, lavatories, and showers.

An accessible opening with a removable plug or cap installed in a drainage pipe to allow inspection and clearing of blockages with drain cleaning tools.

A drainage pipe that extends horizontally from a fixture or group of fixtures to a soil or waste stack, building drain, or branch.

The length of a pipe measured along its centerline, including fittings and changes in direction, used in sizing and slope calculations.

A vertical vent pipe installed to provide air circulation to a drainage stack and to relieve pressure, extending from the stack to the vent terminal.

The extension of a soil or waste stack above the highest fixture connection, serving as a vent for that stack and terminating outdoors.

The open end of a vent pipe that extends outdoors above the roof to admit air and release gases, subject to height and location rules.

A one-way valve that opens to admit air into a drainage system when pressure drops and closes to prevent sewer gases from escaping into the building.

A vent that also serves as a drainage pipe for fixtures other than the fixtures it vents, allowed only under specific code conditions.

A fitting or device that retains a liquid seal to prevent sewer gases from passing into the building while allowing wastewater to flow through.

The vertical depth of liquid held in a trap between its outlet and the dip, blocking the passage of sewer gas into the building.

The portion of a fixture drain between the trap weir and the point where it connects to a vent or drainage stack.

A device installed in a drainage line to separate and retain fats, oils, and grease from wastewater before it enters the sewer, reducing blockages.

A piping system that conveys rainwater, surface water, and other clear water from roofs, yards, and areas to a point of disposal.

A receptacle installed on a roof to collect rainwater and direct it into a leader or storm drainage system, with a strainer to keep out debris.

A vertical pipe that carries rainwater from a roof drain or gutter to a storm drain, sometimes called a downspout or conductor.

Natural gas, liquefied petroleum gas, or a mixture of gases used for heating, cooking, or power, distributed through piping to appliances.

A fitting or piping arrangement installed downstream of a gas appliance control valve to collect dirt, scale, and condensate before they enter the appliance.