CO Plumber key terms

A physical separation between the end of a water supply pipe and the flood-level rim of a fixture or receptacle. The open space prevents used water from being siphoned back into the potable supply.

Any actual or potential link between a potable water system and a source of contamination or pollution. Such a link can allow backflow to carry harmful substances into drinking water.

A device or assembly installed to stop water from flowing backward into the potable supply. It protects drinking water from contamination caused by backpressure or back-siphonage.

A backflow-prevention device that opens to atmosphere when supply pressure drops, breaking a siphon. It is commonly used on hose bibs and flush valves to protect potable water.

A safety procedure that isolates energy sources and locks them off before work begins. Tags warn others not to restore power or pressure while a worker is exposed.

A space large enough for a worker to enter but with limited entry or exit and not designed for continuous occupancy. It may contain hazardous air or engulfment risks requiring testing and permits.

Personal protective equipment such as gloves, safety glasses, hard hats, and respirators. It is the last line of defense against workplace hazards and must fit and be used correctly.

A numerical value assigned to plumbing fixtures based on their probable discharge rate and use. Plumbers add fixture units to size drain, vent, and water-supply piping.

Drainage, waste, and vent piping. This system carries sewage and gray water away from fixtures and provides air paths that protect trap seals from siphonage.

A vertical pipe that carries toilet waste and other soil drainage from fixtures down to the building drain. It usually extends upward to connect with the vent system.

A vertical vent pipe that provides air to a drainage system and releases sewer gases above the roof. It helps maintain atmospheric pressure so trap seals are not siphoned.

A U-shaped fitting that holds a water seal to block sewer gases from entering a building. It is required at most fixture drains unless a listed alternative is approved.

The pipe section between a fixture trap and its vent connection. Its length and slope are limited so the trap seal is not siphoned or pushed out.

An accessible opening with a removable cap in drainage piping. It allows plumbers to clear blockages with augers or jets without cutting the pipe.

The lowest horizontal piping of a drainage system that receives soil and waste from stacks and branches. It ends where it passes through the building foundation or wall.

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

The downward pitch of horizontal drainage pipe, usually stated as fall per foot. Proper slope lets wastewater and solids flow without clogging or leaving standing water.

The piping system that delivers potable water from the service line or meter to fixtures and appliances. It is sized for pressure, flow, and fixture demand.

A fitting that separates two different metals with an insulating material to prevent galvanic corrosion. It is often used where copper and steel piping connect.

Cross-linked polyethylene flexible tubing used for hot- and cold-water distribution. It is joined with approved fittings and must be protected from sunlight and physical damage where required.

Metal tubing commonly used for potable water and heating lines. It is durable and resists corrosion but requires approved joining methods and protection from dissimilar-metal contact.

A metal alloy melted to join copper tubing and fittings. Lead-free solder is required for potable water; the joint must be cleaned and fluxed before heating.

A temperature and pressure relief valve on a water heater. It opens automatically if temperature or pressure exceeds safe limits, preventing a tank explosion.

A closed tank with a flexible diaphragm or air cushion that absorbs the volume increase when water is heated. It prevents excess pressure in a closed water system.

A sacrificial metal rod inside a water heater tank that corrodes before the steel tank does. It protects the tank lining from rust and extends heater life.

A tube inside a water heater that delivers cold water to the bottom of the tank. A broken dip tube can reduce hot-water output and mix cold water with hot.

A shallow pan placed under a water heater to catch leaks. It must be piped to an approved drain or discharge point where leakage could cause damage.

A device or piping arrangement that adds water to a floor drain trap to keep its seal from evaporating. It prevents sewer gas from entering the building.

A fitting installed on a gas line near an appliance to collect dirt and moisture before they reach the controls. It has a capped drip leg that can be cleaned.

An official authorization from the local building department to perform plumbing work. It ensures the work is reviewed and inspected for code compliance.

An inspection performed after pipes are installed but before walls, floors, or ceilings are closed. It verifies drainage, venting, water piping, and supports are correct.

The last inspection after fixtures and appliances are installed and the system is tested. Approval confirms the completed work complies with code and the permitted plans.

The state board that licenses plumbers and oversees plumbing rules in Colorado. It works with local jurisdictions and adopts code requirements for plumbing work.

A credential allowing a plumber to perform plumbing work under the rules of the licensing authority. In Colorado, it is issued by the state after meeting experience and exam requirements.

A person learning the trade while working under a licensed plumber. Apprentices must be registered and work within supervision ratios and scope limits set by the state.