The withstanding of any material to rubbing, scratching, or wearing away.

The total pressure equal to that measured from an absolute vacuum. It equals the sum of gauge pressure plus barometric atmospheric pressure. It is expressed in pounds per square inch (psia) or kilopascals per square meter (kPa/m2).

Temperature measured from absolute zero.

The point at which any substance has no molecular motion and no heat. It is equivalent to -459.72°F or -273.18°C.

The soaking up of a gas or liquid into a solid substance.

A panel that can be opened and used to provide easy approach to concealed valves or equipment.

That which enables a fixture, device, or appliance to be easily reached.

The degree of agreement between a measured value and the true value of a quantity or concern.

That which enables direct approach, either with or without the removing or moving of any panel, door, or similar obstruction. Regarding physically challenged individuals, a plumbing fixture, site, building, facility, or portion thereof that can be approached, entered, and/or used.

The amount a pressure, temperature, liquid level, or differential pressure deviates higher from a set value.

A container in which fluid is stored under pressure as a source of power.

A fluid with a pH lower than 7.0.

A pipe venting an acid-waste system.

A pipe that conveys liquid waste matter having a pH of less than 7.0.

Sewage sediment, rich in destructive bacteria, that can be used to break down fresh sewage quickly.

A movable component of a valve that when operated causes the closure element to move.

With reference to inlet conditions, the volume rate of air compressed and delivered at the discharge point.

Any fitting that mates or connects two pipes or fittings of different size, material, or design.

A substance capable of holding two or more objects together by attaching to their surfaces.

Air compression that allows an increase of temperature in the air.

The surface retention or adhesion of a gas on the surface of a solid.

Also called the authority having jurisdiction, the individual official, board, department, entity, or agency established and authorized by a state, county, city, or other political subdivision created by law to administer and enforce the provisions of a particular code as adapted or amended.

An artificial method of bringing a liquid into direct contact with air.

Living or active only in the presence of free oxygen.

A small vapor particle suspended in air

A device used to lower the temperature of a gas after the compression process.

The effect of exposing material to a specific environment for an extended period of time.

A one-way valve designed to open and allow air to enter a drainage system when negative pressures are present without extending to the outside air and then positively close by gravity.

A device, either made up of fittings or manufactured, installed on a piping system for the purpose of attenuating a pressure surge resulting from water hammer.

Air at any pressure greater than atmospheric pressure.

Air subject only to ambient atmospheric conditions.

The unobstructed vertical distance between the end of a pipe and the flood level of a plumbing fixture or receptacle.

Sometimes called vapor lock, a condition in which a gas is entrapped between two liquid surfaces in a conduit causing a stoppage or impediment.

Air having a temperature of 60°F (15.6°C), with a pressure of 14.70 psia (101.4 kPa) and 0 percent humidity. These figures may be different outside the United States.

A test using compressed air applied to a plumbing system for the purpose of determining a leak.

Any audible or visible signal indicating the existence of any condition or operation outside a preset normal.

A check valve, equipped with a signaling device, that will annunciate a remote alarm when a sprinkler head is discharging.

A fluid with a pH of 7.0 or higher.

A substance composed of two or more metals or a metal and nonmetal intimately united, usually fused together and dissolving in each other when molten.

A metallic pipe composed of two or more metals.

The average or mean temperature of the surrounding air where a reading is taken.

A type of screw thread commonly used on pipe and fittings.

A device that magnifies the input signal using power other than that from the signal itself.

A measurement of the distance between the highest to the lowest excursion of a variable or physical motion.

Living or active in the absence of free oxygen.

Separation and measurements of component parts.

A device used to fasten or secure pipes to a building or structure.

In a pipe, the angle between radial lines from the beginning and end of the bend to the center.

Common term for right-angle valves used to control water supplies to plumbing fixtures.

A device, usually of the globe type, in which the inlet and outlet are at right angles.

A negatively charged atom attracted to the negative electrode.

A procedure for preventing or removing stress within a material through controlled heating and/or cooling.

A term used to describe any device that eliminates siphonic action.

A term, expressed in degrees, indicating how close the outlet temperature of a fluid being heated in a heat exchanger comes to the temperature of the heating medium.

Accepted or acceptable under an applicable specification or standard stated or cited for the proposed use under the procedures and authority of the administrative authority.

An organization established for purposes of testing products to approved standards and acceptable to the administrative authority.

A water-bearing underground formation or stratum capable of storing water suitable for development.

A receptacle designed to collect surface or rainwater from a determined or calculated open area.

An enclosed excavated area below grade adjacent to a building open to the weather.

A gas with little or no toxicity, but which could induce unconsciousness or death by replacing air, thus depriving an organism of oxygen.

A fitting or device supplied with water or other fluid under positive pressure that passes through an integral orifice or “constriction,” causing a vacuum.

An event that occurs at an arbitrary time without synchronization to a referenced clock.

A mechanical device consisting of a check valve that opens to the atmosphere when the pressure in the piping drops to atmospheric.

The relative weight of an atom of an element compared to carbon 12.

The organization, office, or individual responsible for approving equipment, materials, installation, or procedure.

The temperature at which a material will ignite and sustain combustion in the absence of a spark or flame.

The closeness of a public sewer to a building based on code requirements, generally 500 ft (151 m) or less.

Material used to replace excavated material for piping installed in an earthen trench.

The flow of water or other liquids, mixtures, or substances into the distributing pipes of a potable supply from any source other than that intended. The reversal of flow in drainage systems.

A arrangement where backflow can occur.

A device or means to prevent backflow into the potable water system.

A metal strip used to prevent melted metal from the welding process from entering a pipe in the process of making a butt-welded joint.

Negative pressure created by any means in the potable water distribution system which causes a potential backflow.

The flowing back of potentially contaminated or polluted water into the potable water supply piping due to a negative pressure in the potable water supply pipe.

A general sanitary condition where wastewater flows back into a fixture or compartment.

A check valve assembly on the sanitary drainage piping that allows effluent to flow in only one direction.

A tray or partition placed in process equipment or tanks to direct or change the direction of flow.

A check valve that uses a spherical or ball-shaped closure member allowing flow in only one direction.

A connection utilizing a ball in a cuplike shell that allows movement in any direction other than along the axis of the pipes.

A type of quarter-turn valve that uses a spherical closure member.

A condition where no obstruction exists to prevent access by physically challenged individuals.

The lowest point of a stack of vertical pipe. A liquid with a pH of 7.0 or higher.

Several plumbing fixtures located together on the same level, generally a water closet, lavatory, and shower or bathtub.

Any group of two or more adjacent fixtures.

Any material in direct contact with a pipe that is under and up to its centerline.

Commonly called a hub, that portion of a pipe that is sufficiently enlarged to receive the mating spigot end of another pipe for the purpose of making a joint.

Commonly called a hub-and-spigot joint for cast-iron soil pipe, a joint in which the spigot is inserted into the hub and the joint is then made tight by caulking or by a gasket.

Steel pipe that has not been galvanized.

A solid plate flange used to seal off the end of a pipe.

The temperature of a liquid where the internal vapor pressure is equal to the pressure on the surface of the liquid.

An outlet on a boiler to permit emptying or discharge of sediment.

That part of a valve connecting the valve actuator to the valve body; in some valves, it may also contain the stem packing.

A secondary water heating system used to heat water to a higher temperature than that of the primary heater.

Any part of a piping system other than a main, riser, or stack.

A length of soil or waste stack corresponding, in general, to a story height, but in no case less than 8 ft (2.4 m) within which the horizontal branches from one floor or story of a building are connected to the soil stack.

A tee having one side branch.

A vent connecting one or more individual vents to a vent stack or stack vent.

The joining of two pipes using a filler metal that has a melting point more than 1,000°F (538 °C).

The ends of a pipe, valve, or fitting that are prepared for brazing.

The amount of heat required to raise the temperature of 1 pound (0.45 kg) of water 1°F (0.565°C).