ND Journeyman Plumber key terms

A model plumbing code adopted by many jurisdictions that sets minimum requirements for the design, installation, and maintenance of plumbing systems, fixtures, and appliances. Local amendments may modify its provisions.

The individual or agency responsible for enforcing a code, approving materials and methods, and issuing permits and inspections. The AHJ interprets code provisions and may accept alternatives judged equivalent.

The formal process by which a state or local government legally adopts a model plumbing code, often with local amendments. Only the adopted version, as amended, is enforceable in that jurisdiction.

The approval required before installing or altering plumbing work, followed by required inspections at stages such as rough-in and final. Inspections verify that concealed and completed work complies with the adopted code.

The stage of construction when piping, fittings, and fixture supports are installed before walls, floors, or fixtures are finished. Rough-in must be inspected and approved before being concealed.

The drainage, waste, and vent piping network that carries sewage and gray water away while admitting air to protect trap seals. Drain and vent piping are sized and installed as one coordinated system.

A dimensionless measure of the load a fixture places on the drainage or water supply system, based on its probable flow rate and use. Fixture units are totaled to size drain pipes and water service lines.

The drainage load value assigned to a fixture, reflecting the volume and rate of waste it discharges. Drainage fixture units from all connected fixtures are summed to determine required drain pipe size and slope.

A demand value assigned to a fixture based on its hot and cold water flow requirements. Total water supply fixture units, adjusted for the type of building, determine the required size of the water service and distribution piping.

The depth of water held in a fixture trap, typically two to four inches, that blocks sewer gas from entering a building. The seal is maintained by venting and is lost through evaporation, siphonage, or back pressure.

A U-shaped fitting beneath a fixture that holds a water seal and connects the fixture to the drainage system. It must be self-cleaning and accessible for cleaning unless removable without damage.

A vertical vent pipe that extends from the drainage system to open air and provides relief for trap seals. It may serve multiple fixtures and must terminate at the required height above the roof.

A one-way mechanical vent that admits air into drain piping to protect trap seals but does not allow sewer gas to escape. AAVs are permitted only where the code allows and must be installed accessibly.

The lowest horizontal piping of a drainage system that receives waste from soil and waste stacks and conveys it to the building sewer. It is typically sized by total drainage fixture units and installed at a uniform slope.

The pipe carrying sewage from the building drain to the public sewer or private disposal system. It lies outside the building foundation and is usually the owner's responsibility to maintain.

The downward pitch of horizontal drain pipe, expressed as fall per unit of length, that allows gravity flow and solids transport. Insufficient slope causes clogs; excessive slope can separate liquids from solids.

A device installed on a drain line to prevent sewage from backing up into a building when the public sewer surcharges. It is required where fixtures are below the level of the next upstream manhole.

An assembly that prevents contaminated water from reversing flow into the potable water supply. Selection depends on the degree of hazard, and the device must be tested and maintained by qualified personnel.

Any actual or potential link between the potable water supply and a source of contamination or pollution. Cross-connections must be eliminated or protected by an air gap or approved backflow preventer.

An unobstructed vertical separation between a water supply outlet and the flood level rim of a fixture or receptacle. It is the most reliable backflow protection and requires no moving parts.

The pipe carrying potable water from the water main or private source to the building. It is sized using total water supply fixture units and must be installed below the local frost depth.

A device containing a trapped air cushion or piston that absorbs pressure surges when valves close quickly. It is installed near quick-closing valves to reduce noise and protect piping and fittings.

A device that lowers incoming water pressure to a safe level for the building's piping and fixtures. It is required when supply pressure exceeds the code limit and protects against leaks and fixture damage.

The increase in water volume as it is heated, which raises pressure in a closed system such as one with a backflow preventer. A thermal expansion tank absorbs this pressure and prevents relief valve discharge.

A safety valve that discharges water if tank temperature or pressure exceeds safe limits. It must be piped to a safe discharge point, and the discharge pipe must not be capped or reduced in size.

A toilet fixture that receives human waste and discharges it through a trap to the drainage system. Installation requires a water supply, a closet flange, and code-compliant clearances and venting.

A fitting that secures a water closet to the floor and connects its outlet to the drain pipe. It must be set level, fastened securely, and sealed to prevent leakage.

The edge of a fixture or receptacle over which water would overflow onto the floor. It sets the reference height for air gaps and backflow protection and helps determine fixture overflow requirements.

The pipe that carries waste from a fixture trap to the drainage system. It must be sized according to fixture units and slope requirements and is usually vented to protect the trap seal.

An accessible opening in drainage piping that allows a drain snake or rod to clear blockages. Cleanouts are required at specified intervals, at changes of direction, and at the base of stacks.

A waterproof membrane installed under a shower floor to contain water and direct it to the drain. It must be sloped, lapped over the curb, and tested before tile is installed.

Safety gear such as gloves, eye protection, and respirators worn to reduce injury and exposure on the job. Proper use is required when handling chemicals, soldering, or working in confined spaces.

A space large enough to enter but with limited entry or exit and not designed for continuous occupancy, such as a pit or vault. Entry requires atmospheric testing, ventilation, and an attendant outside.

A procedure that isolates energy sources and locks them off before servicing equipment to prevent unexpected startup. Only the person who applied the lock may remove it, following the site's energy control program.

A pressure test in which a piping system or container is filled with water and checked for leaks at a specified pressure. It verifies the integrity of drainage and water piping before concealment or final approval.

A heavy adjustable wrench with serrated jaws used to grip and turn threaded pipe and fittings. Correct sizing and proper jaw direction prevent damage to pipe and reduce slipping injuries.

Materials used to join copper tubing by capillary action, where flux cleans the metal and solder fills the joint gap. Lead-free solder is required for potable water piping.

Wastewater from sinks, showers, and laundry that contains low levels of contamination and may be reused for irrigation under code conditions. It excludes toilet waste and kitchen sink discharge.