ASPE Plumbing Engineering Design Handbook: Formulas, Symbols, and Terminology

A comprehensive set of vocabulary flashcards covering the plumbing terminology, fire protection systems, medical air systems, and SI unit standards found in the ASPE Plumbing Engineering Design Handbook.

Abrasion

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

Absolute pressure

The total pressure measured from an absolute vacuum, equal to the sum of gauge pressure plus barometric atmospheric pressure, expressed in $\text{psia}$ or $\text{kPa/m}^{2}$.

Absolute zero

The point at which any substance has no molecular motion and no heat, equivalent to $-459.72^{\text{o}}\text{F}$ or $-273.18^{\text{o}}\text{C}$.

Absorbtion

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

Accuracy

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

Acid

A fluid with a $\text{pH}$ lower than $7.0$.

Activated sludge

Sewage sediment rich in destructive bacteria used to break down fresh sewage quickly.

Actuator

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

Adiabatic compression

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

Adsorption

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

Administrative authority

The individual official, board, or agency established by law to administer and enforce the provisions of a particular code; also called the authority having jurisdiction ($\text{AHJ}$).

Aeration

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

Aerobic

Living or active only in the presence of free oxygen.

Aerosol

A small vapor particle suspended in air.

Air-admittance valve

A one-way valve designed to allow air to enter a drainage system when negative pressures are present and positively close by gravity.

Air gap

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

Air lock

Also called vapor lock, a condition where gas is entrapped between two liquid surfaces in a conduit causing a stoppage.

Standard air

Air having a temperature of $60^{\text{o}}\text{F}$ ($15.6^{\text{o}}\text{C}$), a pressure of $14.70 \text{psia}$ ($101.4 \text{kPa}$), and $0$ percent humidity.

Alarm check valve

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

Alkali

A fluid with a $\text{pH}$ of $7.0$ or higher.

Anaerobic

Living or active in the absence of free oxygen.

Antisiphon

A term describing any device that eliminates siphonic action.

Approach

A value expressed in degrees indicating how close the outlet temperature of a heated fluid comes to the temperature of the heating medium.

Aquifer

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

Asphyxiant gas

A gas with little or no toxicity that can induce unconsciousness or death by replacing air and depriving an organism of oxygen.

Aspirator

A device supplied with fluid under positive pressure that passes through an integral orifice causing a vacuum.

Availability of a sewer

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

Backflow

The reversal of flow in drainage systems or the flow of substances into potable supply pipes from any source other than intended.

Backsiphonage

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

Backwater valve

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

Balling joint

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

Bell

Commonly called a hub, the enlarged portion of a pipe that receives the mating spigot end of another pipe.

Boiling point

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

Branch interval

A length of soil or waste stack corresponding to a story height, but not less than $8\text{ ft}$ ($2.4\text{ m}$).

Brazing

The joining of two pipes using a filler metal that has a melting point more than $1,000^{\text{o}}\text{F}$ ($538^{\text{o}}\text{C}$).

British thermal unit (Btu)

The amount of heat required to raise the temperature of $1\text{ pound}$ ($0.45\text{ kg}$) of water $1^{\text{o}}\text{F}$ ($0.565^{\text{o}}\text{C}$).

Building drain

The lowest piping of a drainage system that conveys waste inside the walls to a distance of $2$ to $5\text{ ft}$ ($0.70$ to $1.70\text{ m}$) outside the building.

Building sewer

The horizontal piping extending from the end of the building drain to a public sewer or private disposal system.

Building trap

Also called a house trap, a device installed in the house drain to prevent air circulation between the house drain and house sewer.

Burst pressure

The maximum design pressure, usually four times normal operating pressure, applied to a piping assembly without causing rupture.

Butterfly valve

A valve with a wing-like disc that operates at right angles to the flow.

Capillary

The action by which a liquid is drawn into a void, primarily observed during soldering.

Cathodic protection

The control of electrolytic corrosion by applying an electric current so a structure acts as a cathode.

Cavitation

The formation of bubbles in a liquid due to a partial vacuum, which damages adjacent parts when bubbles revert to liquid.

Circuit vent

A branch vent serving two or more traps extending from in front of the last fixture to the vent stack.

Combined waste and vent system

A system using horizontal wet venting of fixtures by means of a common pipe sized to allow free air movement above the flow line.

Combustible liquid Class II

A liquid with a flash point at or above $37.8^{\text{o}}\text{C}$ ($100^{\text{o}}\text{F}$) and below $60^{\text{o}}\text{C}$ ($140^{\text{o}}\text{F}$).

Common vent

A vent that connects at the junction of two fixture drains and serves both fixtures.

Conductor

Piping conveying stormwater from a building to a point of disposal.

Critical level

The reference point on a backflow preventer determining the minimum elevation above the flood level rim for installation.

Cross-connection

Any physical arrangement between two separated piping systems (one potable and one unknown) where flow may occur depending on pressure differential.

Dead end

A pipe $2\text{ ft}$ ($0.70\text{ m}$) or more terminated by a plug, cap, or fitting closing off the end.

Developed length

The length measured along the centerline of pipe and fittings.

Dewpoint

The temperature at which water in the air will start to condense on a surface.

Dielectric fitting

A fitting with insulating parts that prohibits the flow of electric current.

Diversity factor

A usage percentage applied to the water flow rate that lowers the connected load based on non-simultaneous fixture discharge.

Domestic sewage

Liquid wastes derived from ordinary living processes free of industrial wastes.

Drainage fixture unit (dfu)

A measure of the probable discharge of a fixture or device into a drainage system.

Durham system

A soil or waste system in which all piping is threaded pipe or rigid tubing using recessed drainage fittings.

Durion

Brand name for a high-silicon alloy with approximately $14.5$ percent silicon that is acid resistant through its entire thickness.

Effective opening

The minimum cross-sectional area at the point of water-supply discharge, applicable to an air gap.

Ejector pump

A mechanical device for removing sanitary waste containing solids from an ejector pit.

Elastomer

A rubber-like substance that returns to its original shape after being stretched to at least two times its length.

Fire department connection (FDC)

An inlet connection receiving pumped water from fire department equipment to supply a building sprinkler or standpipe system.

Fire pump

An approved pump with driver and controls used to supply water for fire protection service.

Flash point

The temperature at which a fluid gives off flammable vapor in sufficient concentration to form an ignitable mixture.

Flood level rim

The top edge of a receptacle or fixture from which water overflows.

Flush valve

A pressurized device supplying a predetermined quantity of water to fixtures; also called a flushometer valve.

Galvanic action

An interchange of atoms carrying electric charge between materials where the anode metal with higher electrode potential corrodes.

Grease interceptor

A plumbing appurtenance installed to intercept oily and greasy wastes while permitting acceptable liquids to flow into a drainage system.

Head loss

The energy loss of a fluid as it passes through a flow passage; also called pressure drop.

Indirect waste

A discharge to the drainage system through an air gap as a method to avoid cross-connections.

Invert

The lowest point on the interior of a horizontal pipe.

Jockey pump

Properly known as a pressure maintenance pump, used to maintain pressure in a fire protection system without operating the fire pump.

Medical air

Pharmaceutical air used for life support, supplied from cylinders, bulk containers, or medical air compressors.

Medical support gas

Nitrogen or instrument air used for medical purposes, such as operating surgical tools, and not respired as part of treatment.

Pendent sprinkler

A sprinkler designed so that the water stream is directed downward against the deflector.

Potable water

Water of sufficient purity suitable for human use and meeting quality standards of the health authority having jurisdiction.

Reduced pressure zone backflow preventer

A device consisting of two independent check valves separated by an intermediate chamber intended to discharge water that backflows.

Roughing in

The installation of all parts of a plumbing system that can be completed prior to fixture installation, including piping and supports.

Suds pressure zone

The portion of a waste stack where the formation of soap suds could create pressure higher than atmospheric.

Tepid

A moderate water temperature between $60^{\text{o}}\text{F}$ and $100^{\text{o}}\text{F}$ ($16^{\text{o}}\text{C}$ and $38^{\text{o}}\text{C}$).

Trap seal

The maximum vertical depth of liquid a trap retains, measured between the crown weir and the top sum of the dip.

Water hammer

A surge pressure resulting from a sudden start or stop of water.

Wet vent

A vent that also serves as a drain.

SI Base Unit for Length

meter ($\text{m}$)

SI Base Unit for Thermodynamic Temperature

Kelvin ($\text{K}$)

SI Base Unit for Intensity

candela ($\text{cd}$)

Soft conversion

A conversion to the SI unit value in software only, where material products remain physically unchanged.

Hard conversion

A conversion where product or material characteristics are physically changed to preferred SI unit values.