IL Plumber key terms

The unobstructed vertical distance through free atmosphere between the lowest opening of a water supply outlet and the flood-level rim of the receiving fixture or vessel. It is the strongest form of backflow prevention because no mechanical part can fail.

The unwanted reversal of water flow in a piping system, carrying nonpotable water or other substances toward the potable supply. It occurs either by backsiphonage, driven by negative pressure, or by backpressure, driven by a downstream pressure higher than supply pressure.

Backflow caused by a drop in supply pressure below atmospheric or below downstream pressure, which pulls contaminants into the potable system. Main breaks, heavy firefighting demand, or nearby high-volume use can create the vacuum that triggers it.

Backflow caused when pressure downstream of a connection exceeds the pressure in the potable supply, pushing nonpotable fluid backward. Pumps, boilers, thermal expansion, and elevated tanks are common sources of the higher downstream pressure.

Any actual or potential physical link between a potable water system and a source of contamination or pollution. Even a temporarily connected hose, submerged inlet, or jumper can create one, and each must be eliminated or protected by an approved method.

An assembly with two independently acting check valves and a hydraulically operating differential relief valve between them. It protects against both backsiphonage and backpressure at high hazard and must be tested in place after installation and at required intervals.

Two independently acting check valves in series, with test cocks, used to protect against backflow where the hazard is low and backpressure may occur. It is not approved for high-hazard or toxic connections and must be field tested.

A device that admits air into a pipe to break a vacuum and stop backsiphonage. Pressure-type and atmospheric-type models serve different fixtures, and the atmospheric type must be installed at least six inches above the highest downstream outlet.

The edge of the receptacle from which water overflows, such as the top of a fixture or the top of a standpipe. It is the reference point for measuring air gaps and setting the critical level of backflow assemblies.

The marked line on a backflow assembly or plumbing fixture that establishes the minimum height above which the device must be installed. It is the reference elevation that keeps the device above the flood-level rim so discharge or venting works correctly.

Water that is safe for human consumption and meets applicable bacteriological, chemical, radiological, and physical quality standards. Plumbing must deliver it without contamination from fixtures, equipment, or nonpotable sources.

Water not approved for drinking or culinary use, including reclaimed, gray, rain, and industrial water. Its piping must be identified, separated from potable lines, and protected so that no cross-connection can occur.

The increase in water volume as it is heated in a closed system, which raises pressure and can cause relief valve discharge or backflow. Control is provided by an expansion tank, a thermal expansion valve, or an approved relief arrangement.

A safety device that opens to discharge water when tank pressure or temperature exceeds its setpoint, preventing rupture. It must be rated for the heater, piped to a safe discharge point, and never capped or plugged.

An appliance that heats potable water for domestic use, commonly by gas, electric, or indirect means. It requires a temperature and pressure relief valve, a drain pan where leakage could cause damage, and correct venting and combustion air for fuel-fired units.

A device or assembly installed to stop reverse flow between systems. Selection depends on hazard level, whether backpressure or backsiphonage is possible, and local code requirements for testing and inspection.

A dimensionless measure of the load a plumbing fixture places on the drainage or water supply system relative to a standard fixture. Fixture units let designers size pipes from total demand rather than by simply adding fixture flows.

A value assigned to a fixture reflecting its probable discharge rate and waste load for sizing drainage piping. Values are tabulated by fixture type, and branch and building drain sizes are selected from total drainage fixture units.

A value reflecting a fixture's probable hot and cold water demand for sizing supply piping. Because not all fixtures operate at once, total water supply fixture units are converted to probable flow for pipe sizing.

The total measured length of pipe along its run, including fittings and changes of direction, used to size pipe and select pumps. Fittings add equivalent length, so a short straight run with many elbows can behave like a much longer pipe.

The pipe and appurtenances carrying potable water from the public main or private source to the building. It includes the meter, valves, and backflow protection, and is sized for peak demand and available pressure.

The lowest piping of a drainage system that receives waste from soil and waste stacks and conveys it to the building sewer. It extends to a point outside the building wall, where it becomes the building sewer.

The drainage pipe carrying sewage from the building drain to the public sewer or private disposal system. It begins outside the building foundation and is sized and sloped to maintain scouring velocity.

A fitting that holds a water seal to prevent sewer gas from entering a building. Each fixture must have a trap unless specifically exempted, and traps must be vented and protected from siphonage and evaporation.

The vertical depth of water in a trap that blocks the passage of air and gas. It must be maintained at the code-required depth, and shallower seals can be lost by evaporation, siphonage, or turbulence.

The portion of a drainage pipe between the fixture trap and the point where the pipe connects to a stack or branch. Its length and fall are limited so that the trap is not siphoned and the trap arm remains self-cleaning.

A vertical pipe that provides air to a drainage system so traps keep their seals and flow is smooth. It extends through the roof or connects to an approved vent terminal and must be sized with the drainage it serves.

The open end of a vent pipe that admits air and releases gases above the building. It must be located where gases will not enter windows, doors, or air intakes and at the height required by code.

An access fitting that allows a drain or sewer to be cleared of blockages. It must be the same size as the pipe it serves, accessible, and provided at required locations such as changes in direction and long runs.

The fall of a drainage pipe per unit of horizontal run, expressed in inches per foot or as a percentage. Correct slope keeps solids moving and prevents both clogging from too little pitch and self-siphoning from too much.

The practice of installing, altering, repairing, and maintaining piping, fixtures, and appurtenances that supply water and remove waste. It includes drainage, vents, water heating, and related systems that affect health and safety.

A person licensed under Illinois law to perform plumbing work. The license is issued by the State and may be a journeyman or master level, with different authority to supervise and contract for work.

A plumber licensed at the highest level, authorized to design, supervise, and contract for plumbing work and to employ or supervise journeymen and apprentices. A master license is generally required to hold a plumbing contractor license.

A licensed plumber qualified to perform plumbing work under the supervision of a master plumber or licensed contractor. The journeyman may not independently contract for plumbing work.

A person learning the trade under a registered apprenticeship and the supervision of a licensed plumber. Apprentices may perform plumbing work only within the terms of their apprenticeship and applicable law.

A business entity licensed to engage in the plumbing business in Illinois, operating through a licensed master plumber. The contractor is responsible for permits, code compliance, and the work performed under its license.

Written authorization from the authority having jurisdiction to install, alter, or repair plumbing work. Work must not begin before the permit is issued, and inspections are required at specified stages of construction.

The official review of plumbing work at required stages to confirm compliance with the code and approved plans. Concealed work must be inspected before covering, and final inspection follows completion and testing.

The stage of plumbing installation when piping is in place but fixtures and trim are not, before walls and floors are closed. Rough-in must be inspected and tested before concealment.

The last inspection after fixtures, trim, and equipment are installed and the system is tested and operational. Approval at final inspection closes the permit and confirms the work is complete and code compliant.

The official or agency responsible for enforcing the plumbing code and issuing permits and inspections. Its approved interpretations govern local compliance and may add requirements beyond the statewide minimum.

The statewide plumbing regulation adopted under Illinois law that sets minimum requirements for plumbing materials, design, installation, and inspection. Local governments may adopt stricter rules but may not weaken the statewide minimum.

The administrative rules implementing the Illinois Plumbing License Law, covering licensing, examinations, continuing education, and disciplinary procedures. It works together with the statute to govern who may perform plumbing work.

The Illinois statute, 225 ILCS 320, that establishes licensing requirements for plumbers and plumbing contractors and authorizes enforcement and discipline. It defines unlawful practice and the scope of regulated plumbing work.

Performing plumbing work without the required license or outside its authorized scope. It can lead to cease-and-desist orders, fines, and discipline, and it exposes the unlicensed person and any enabling contractor to liability.

Required coursework a licensee must complete to renew a plumbing license. It keeps practitioners current on code changes, safety, and public health protection, and completion must be documented for renewal.