Plumbing NC I key terms

Gear worn to reduce injury risk on site, such as safety glasses, gloves, hard hat, hearing protection, and steel-toe boots. It supplements, but never replaces, safe work procedures and guards.

The process of spotting conditions or acts that could cause harm before work starts and as conditions change. Findings are reported and controlled through elimination, substitution, engineering controls, or administrative measures.

A procedure for isolating energy sources, such as electricity, gas, or pressurized water, and applying locks and warning tags so equipment cannot be started while someone works on it.

An enclosed or partly enclosed area with limited entry and exit that is not designed for continuous occupancy and may hold hazardous gas or low oxygen. Entry usually requires a permit and monitoring.

A written instruction authorizing a specific job, listing the location, scope, materials, and any safety or access conditions. It links field work to the client's request and to record keeping.

A short, regular briefing before or during a shift covering the day's tasks, hazards, controls, and questions from the crew. It is documented so attendance and topics can be verified.

A fitting or assembly that stops used or contaminated water from reversing into a clean supply. Common types include air gaps, vacuum breakers, and reduced-pressure zone assemblies.

Any actual or potential link between a potable water system and a source of contamination. It must be removed or protected by an approved backflow device.

Water fit for human consumption that meets the applicable drinking-water quality standard. Supply piping, fittings, and joining materials in contact with it must be approved for that use.

A valve used to shut off flow to a section of piping so it can be repaired, tested, or isolated for safety. It is closed and usually locked or tagged during work.

A valve with a sliding wedge that opens or closes the flow path with minimal resistance when fully open. It is intended for on/off service, not for throttling flow.

A valve in which flow passes through a seat and plug arrangement that allows reasonably fine throttling. Its higher pressure loss makes it less suitable for simple shutoff duty.

A pressure surge caused when moving water is stopped or redirected suddenly. It produces banging noise and can damage pipes and fittings, so arrestors and proper support are used.

A device containing a trapped air or gas cushion that absorbs the pressure spike created when flow stops abruptly. It is installed near quick-closing valves and appliances.

The downward slope of a horizontal drain pipe that lets wastewater and solids move by gravity. Too little slope causes blockage; too much leaves liquids behind and clogs solids.

A fitting holding a water seal that blocks sewer gas from entering a building while allowing wastewater to pass. Each fixture normally has its own trap.

The pipe section between a fixture trap and the point where it connects to the drainage stack or branch. Its length and fall are limited to protect the trap seal.

A vertical pipe that admits air into the drainage system and releases sewer gases above the roof. It protects trap seals by keeping pressure in the system near atmospheric.

An accessible opening fitted with a removable plug or cover that allows a drain to be rodded or inspected when it blocks. It is placed at the base of stacks and ends of runs.

Piping that carries sewage containing solids from water closets to the drainage system. It is distinguished from waste pipe, which carries liquid waste without fecal solids.

Piping that carries liquid waste from fixtures other than water closets, such as sinks and showers. It connects to the drainage system and is protected by traps and vents.

The stage of installation where supply and drainage connections are positioned and stubbed out before fixtures and finished surfaces are installed. Dimensions come from the approved drawings.

The distance from a finished wall, floor, or reference line to the center of a pipe connection, used to place plumbing so the fixture lines up correctly after finishing.

A support bracket fixed to structure that holds a wall-mounted fixture and its drain connection in position. It carries the fixture load so the finished wall is not relied on.

A toilet fixture that receives human waste and discharges it through a trap to the soil pipe. Installation requires correct rough-in, secure fixing, and an adequate water supply.

A valve that releases a measured volume of water from the supply directly into a fixture for flushing. It needs adequate pressure and flow to work and is often used in commercial toilets.

A drawing showing pipe routes, sizes, fixture locations, valves, and connections for a building's water and drainage systems. It is read with sections, risers, and specifications.

A schematic drawing that shows how vertical stacks and horizontal branches connect floor by floor, with pipe sizes and fixtures. It is not drawn to scale and shows relationships, not distances.

A three-dimensional style drawing using angled axes to show pipe runs in length, width, and height on one view. Plumbers use it to plan offsets and fittings before fabrication.

The ratio between a distance on a drawing and the real distance it represents, such as 1:50. It is used to take measurements and check pipe runs against site conditions.

A quantified list of pipes, fittings, valves, fixtures, and supports needed for a job, prepared from drawings and specifications. It drives ordering and reduces site waste.

A pair of bends that shifts a pipe run sideways or vertically to avoid an obstruction or reach a new line. The bend angle and travel length are calculated from the offset distance.

Forming a pipe to a required angle or curve using heat, a bender, or a bending machine. Bend radius and wall thinning must stay within limits so flow and strength are not reduced.

Cutting a tapered screw thread on a pipe end so it can be joined with a threaded fitting. Correct thread length and lubrication are needed to avoid leaks and split fittings.

A cutting tool with hardened teeth that forms external threads on pipe. It is held in a stock or power threader and is sized to match the pipe diameter and thread standard.

A hand or power tool that cuts pipe by rotating a hardened wheel against it while tightening. The burr left inside must be reamed out before the pipe is joined.

A tool that removes the internal burr left by a pipe cutter or saw. Clearing the burr restores full bore and prevents turbulence and debris in the system.

A joint made on plastic pipe by applying solvent cement that softens the surfaces so they fuse. Surfaces must be clean and dry, and the joint held still while it sets.

A hanger, bracket, or clamp that carries pipe weight and keeps spacing and alignment within limits. Correct support prevents sagging, vibration, and stress on joints.

A tool with a sealed bubble vial used to check whether a surface or pipe is horizontal or vertical. It is essential for setting drainage fall and aligning fixtures.