The complete plumbing glossary

A Valve – a manual gas shut-off valve

ABS – Acrylonitrile Butadiene Styrene – a stiff, plastic pipe  and fittings used for drain, waste and vent lines

Absolute pressure – the result of atmospheric pressure added to gauge pressure

Absorption field – leech field engineered to receive septic tank sewage

Adjusting link – adjustable strap/bar, which forms a connection between the lift rod of a faucet and the ball lever of the drain

Aerator – a device screwed into a faucet spout, which mixes air into running water to control flow and reduce splashing

Air chamber – vertical, air-filled pipe or spring coil set above the water line to absorb pressure when water is turned off at the faucet

Air gap – air-filled space, which allows contaminated water to discharge freely without coming back into the water supply

Air lock – a blockage in liquid flow

Air volume control – maintains air charge in a standard water tank

Alkalinity – the measure of elements in water, which determine its alkaline conditions

Americast – a patented process, which uses a porcelain surface, an enamelling grade steel material and a structural composite backing bonded together to create a sink that is durable like cast iron but considerably lighter

Angle seat wrench – valve seat wrench with a 90 degree bend

Angle stop – a shut-off valve between water pipes and a faucet, usually used in an emergency repair

Angular discharge tube – discharge tube that changes direction of water flow to 90 degrees

Anode rod – a rod within a heater, which is composed of one or more metals and protects the tank from corrosion

Anti-clog suction – a whirlpool water recirculating system, which prevent clogging but doesn’t restrict water flow

Anti-siphon – prevents backflow of water into a system

Apron – the skirting of a bathtub that covers the rough-in area from the floor to the top of the appliance

Aquastat – thermostat that is submerged in water

Aquifier – a zone below the earth’s surface that is capable of yielding a significant volume of water – its upper level is called the water table

Arrow head – heavy duty auger cable trip

Auger – flexible rod with a curved end used to access a toilet’s built-in trap and remove clogs

Back pressure – pressure that resists the flow of fluid in a piping system

Back siphonage – negative pressure that causes back flow

Back vent – plumbing fixture’s separate vent in a building drainage system

Back wash – the process of cleaning a filter by reversing the flow of water through it – the dirt is sent to the waste disposal

Back flow – when water from one system backs into any part of the main distribution system

Back flow preventer – a device that stops back flow – required for sprinkler systems and handheld showers

Backjet – Whirlpool jets located on the fixture wall behind a reclining bather

Backwater valve – sewer line valve that prevents sewage flowing back into the house

Baffle – an object placed in an appliance to change the direction of the flow of air and gases

Ball check valve – a valve that uses a ball to seal against a seat to stop flow in one direction

Ball joint – spherical assembly allowing pivot rotation for many bathroom and shower accessories

Ball passage – refers to the size of the ball that can pass through the trapway of a toilet – it also relates to the trapway size

Ballcock – the fill valve that controls the flow of water from the water supply line into a gravity-operated toilet tank

Barlow’s formula – an equation which shows the relationship of internal pressure to allowable stress, nominal thickness and diameter

Barrier-free – relating to handicap access – e.g. a shower enclosure with minimal bottom track and opening to ease wheelchair access

Base – a substance that releases hydroxyl ion when dissolved in water

Basin wrench – a wrench with a long handle and jaws mounted on a swivel to reach nuts to fasten faucets on a previously installed tank

Batch feed – type of garbage disposer in which waste is fed into unit one load at a time, then activated by placing a stopper into the drain opening

Bernoulli’s law – the principle that a stream of liquid or gas exerts less sideways pressure while in motion than at rest

BHP – brake horse power – the amount of horsepower being consumed by a pump as measured on a dynamometer

Blowbag – a drain-cleaning device consisting of a rubber bladder with a hose fitting on one end and a nozzle on the other – the device attaches to a water hose and is inserted into a clogged drainpipe – as the water is introduced, it expands to grip the pipe and releases pulsating bursts of water through the nozzle, forcing water through the pip to clear an obstruction

Blowdown – partial venting or draining, under pressure of the water side of a boiler to reduce or remove unwanted contaminants

Brackish water – water containing bacteria between 1, 000 and 15, 000 ppm of dissolved solids

Butterfly valve – a serviceable valve that allows water to flow through it when open and stops the flow when closed

BX cable – metallic sheathed cable containing A/C electrical wiring – typically used when wiring would otherwise be exposed

Carbonising – in a pump, where a reduction of hydrocarbons results in the formation of carbon residue that will interfere with the movement of a mechanical seal – often called coking

Cartridge – typically refers to a valve cartridge – it is a single-piece unit that replaces the use of separate seats, stems and seals for water flow

Casing – a tubular structure intended to be watertight – it is installed in the drilled hole to maintain the well opening and prevent ground water from entering

Catch basin – large underground container with a grate on top for collection of storm water – it catches debris and prevent steams and lakes being contaminated

Cathode – a negatively charged electrode

Cation – a positively charged ion in an electrolyte solution, which is attracted to the cathode by a difference in electrical potential

Cavitation – the vacuum created when the discharge of the pump exceeds the replacement in the suction line

Chain wrench – an adjustable wrench, in which a chain is used for gripping

Chamfer – bevelled end

Check stop – shut-off valve used with tub/shower faucet that is activated by turning a slotted stem with a screwdriver – also known as a screwdriver stop or a service stop

Check valve – a type of back flow preventer installed in a pipe that allows water to flow in one direction

Circuit vent – plumbing drainage system vertical vent, which is run from the last two traps on a horizontal drain line to the main vent stack of a building drainage system

Cistern – rainwater storage tank, often underground

Clevis – a U-shaped piece of metal with holes in the ends, through which a pin is run to attached to pipes

Closed system – a system where the incoming cold water supply has a device that will not allow water to expand when heated

Conduit – tube that houses electrical wiring

Cowl – a short fitting used to join two pieces of pipe

Crocus cloth – finer than sandpaper grit on a cloth backing

Cross-connection – any connection that may allow wastewater to enter the supply system

Crown-vented trap – an air admittance valve attached to a drainpipe, protected by a valve, designed to equalise pressure in the drain line and to protect the trap seal

Crows foot – a PVC tee with twin outlets at right angles off the main

Dam – the barrier built into a trapway of a toilet that controls the water level in the bowl

DC – Direct Current – electrical supply in which the polarity of the two wires does not change

Deionisation – process of reducing water to a non-mineral state by passing it over a bed of resins

Diaphragm – flexible membrane in a valve that deflects down onto a rigid area of the valve body to regulate water flow from the supply lines to eliminate accumulation of debris inside

Die – cutting device used to thread pipe

Dip tube – tube inside water heater that sends cold water to the bottom of the tank

Direct vent – a system that pulls outside air for combustion and vents combustion gases directly outside without a chimney

Directional jet – whirlpool air discharge unit with pivot allowing discharge path to be adjusted by user

Directional tee – tee fitting that allows direct flow in one direction by use of an internal baffle

Dishwasher tailpiece – a flanged adaptor connecting a basket strainer to the drainpipe with a dishwasher inlet

Dope – pasty lubricant used on a seal pipe thread prior to making a threaded pipe connection

Double extra strong – standard pipe weight designation, sometimes call XXH

Down head boring gimlet – a flexible cutting tip for an auger cable

Drain valve – device that allows drainage of stored contents from a water heater

Drainage tile – historically, pipe shaped clay tiles installed in below-grade trenches for gravity-rated drainage but now PVC pipes are more commonly used

Drawdown – the distance the water level drops below standing water level while pump is operating

Drip leg – a stub end pipe placed at a low point in the gas piping to collect condensate and permit its removal

Duovalve – a twin valve (hot and cold) with a single on/off lever used for washing machines

Duplex basin – an ejector pump container, large enough for two pumps, used in multi-family buildings

DWV – Drainage, Waste and Vent systems, which remove wastewater

Dynamic pressure – the pressure when the water is flowing

E Coli – the common abbreviation of Escherichia Coli, which is one of the members of the Coliform groups of bacteria

Eccentric shank – a fitting with a shank, in which the centreline is offset to allow minor compensation for supply lines that would be difficult to precisely position

ECO – Energy Cut Off – a safety device designed to shut power off to the water heater and prevent high temperature

Eductor – a device utilising a nozzle and throat that is installed in a stream of water to create a partial vacuum to draw air or liquid into the stream – it’s commonly used to draw regeneration chemicals into an ion exchange water treatment system, such as a softener

EF – Energy Factor – a measure of the overall efficiency rating of the water heater based on the model’s recovery, efficiency, stand-by loss and energy input

Elbow – sometimes called an ell – a fitting used to change the direction of rigid pipe or tubing

Elevation – the vertical distance between the level where fluid enters a pipe and the level where it leaves, which must be added to the total discharge head if the inlet is lower than the outlet and subtracted if the inlet is higher

EMT – Electrical Metal Tubing – a galvanised steel pipe used to carry electrical or other types of conductors

Expansion tank – a tank designed to absorb excess pressure due to thermal expansion

Expansion valve – thermostatically controlled valve that controls liquid refrigerant

Extinction pop – a flashback occurring when a burner is turned off

Extra strong – sometimes called extra heavy – a standard pipe weight designation

Face plate – trim piece found behind a single-control wall-mount faucet handle – also known as a dial plate

Facultative bacteria – bacteria that can live under aerobic and anaerobic conditions

Fall/flow – the proper slope or pitch of a pipe for adequate drainage

Faucet – an exposed plumbing fitting used to control the flow of water to a basin

Feed pump – a pump that supplies water to a boiler

Ferrous – material containing or derived from iron

First draw – water that has been sitting in pipes or plumbing fixtures overnight and is first drawn when taps are opened in the morning

Fixed cone valve – a cylinder gate mounted with the axis horizontal – also known as a Howell Bunger valve

Flange – a rib or rim for strength, which is present for guiding or for attachment to another object

Flapper – disc-like rubber composite that retains water in the tank, and upon flushing, cycle lifts to release water of the tank to the bowl for a complete flushing cycle

Floating flames – an undesirable burning operating condition, usually indicating incomplete combustion in which flames leave the burner port to reach for combustion air

Flocculant – a chemical substance that promotes the aggregation of coagulation of suspended particles in the water

Flux – paste applied to copper pipes and fittings before soldering to help the fusion process and prevent oxidation

Footprint – the area of floor space taken up by a water heater or other appliance

Freshwater – water that contains less than 1,000 milligrams per litre of dissolved solids – generally, more than 500mg/l of dissolved solids is undesirable for drinking and many industrial uses

Galvanise – the process of applying a coating of zinc to the finished product to provide corrosion protection – the coating can be applied by hot dipping or electrolytic deposition

Galvanometer – Laboratory instrument that detects and measures small electrical currents

Gas cock – plug valve installed in the main gas line

Gasket – flat device, usually made of rubber, which is used to provide a watertight seal between metal joints

Gauge – refers to thickness of stainless steel and is commonly used in reference to quality grades on certain types of lavatories and sinks – for instance, 10 and 20-guage stainless steel sinks have gone through a number of polishing operations to establish a pristine finish

Giardiasis – a disease that results from an infection by the parasite Giardia, caused by drinking water that is either not filtered or not chlorinated

Gland – in a pump, the part that holds one half of the mechanical seal and attaches to the stuffing box

GPF – Gallons Per Flush – the rate of water flow by which toilets and flush valves are measured and regulated

Greensand – a natural mineral, primarily composed of complex silicates, which possess ion exchange properties

Greywater – waste water from sinks, showers and bathtubs, but not from toilets

Grip fitting – a compression-type fitting used on PB pipes

Grounding – connects a piece of electrical equipment to a ‘ground wire’, which is connected to the electrical system ground at the circuit breaker box – this helps to ensure the circuit breaker will trip and cut off power in the event of a short circuit or damage to insulation

Guide arm – the valve that controls water flow in to the toilet tank

Hanger – a device used to support pipes

Hard water – natural water containing impurities in various proportions – traditional hardness is a measure of calcium or dissolved solids in a solution, measured in parts per million

Head – the pressure of water or steam in a closed system – it represents the difference in the gravitational force exerted by a liquid at two different depths

Heat exchanger – a heat transfer system

Heat trap – restriction of heat loss through water connections to a tank

Hermetic – completely sealed, especially against the escape or entry of air

Hertz – a measure of frequency wherein one hertz equals one cycle per second

Hex key – allen wrench

Hold down – a type of pipe anchor consisting of a U-strap bolted at either end on to a horizontal plate

Hollow-jet valve – a valve having a closing member that moves upstream to shut off the flow

Hose bibb – term used for sillcock

HP – horsepower

Hydraulic pressure – pressure that exists in a system containing non-compressible liquid

Hydrolysis – the reaction of a salt with water to form an acid and a base

Hydronic – system of forced hot water

Hydrojet – cold inlet tube designed to reduce sediment build-up and increase efficiency in a water heater

Hydroxyl – the chemical group of ion, which is neutral or positively charged

Hygroscopic – attracting or absorbing moisture from the air changed or altered by this absorption

I.D. – Inside Diameter – all pipes are sized according to their inside diameter

Impeller – rotating wheel with vanes found inside a centrifugal pump; as it spins at high speed it draws fluids in and thrusts them under pressure to the discharge outlet

Induction motor – with a slippage of 2-5% compared to synchronous motors, this is the most commonly used type in the industry

Influent – the stream entering a unit, stream or process, such as the hard water entering an ion exchange water softener

Inserts – faucet handles

Instantaneous water heater – a type of water heater, which heats supply as it passes through with no storage tank necessary – also known as a tankless heater

Ion – an atom or group of atoms that function as a unit and have a positive or negative electrical charge due to the gain or loss of one or more electrons

Ion exchange – a reversible process in which ions are released from an insoluble permanent material in exchange for other ions in a surrounding solution; the direction of the exchange depends upon the affinities of the ion exchanger for the ions present and the concentrations of the ions in the solution

Ionisation – the process in which atoms gain or lose electrons – sometimes used as synonymous with dissociation; the separation of molecules in to charged ions in solutions

IPS – Iron Pipe Size – standard pipe threads (the female IPS refers to internal pipe threads and the male IPS refers to external pipe threads)

Integral stops – stops that allow the owner to shut off water supply at the faucet for maintenance without shutting off the water supply to the entire house

Integral vacuum breaker – a device typically used in a sink or shower sprayer to keep water from flowing back into the fresh water supply

Interceptor – device for separating grease and oil from drainage systems

Isothermal – action that takes place with no change in temperature

J bend – the trap section with a 180-degree bend or a multi-piece P-trap – also called a return bend

J hook – a pipe hanger in the shape of a ‘J’

Jacket – usually refers to the heating or cooling outer casing, which surrounds the stuffing box on some pumps

Jet – a feature of a toilet that is designed to direct water into the trapway quickly to start the siphon action

Jetport – hydro-jet dip tube, which creates turbulence in the tank

Johnni-bolts – closet bolts, used to mount toilet bowls to the closet flange

Joint – one length of pipe

Joint runner – collar-like device that keeps molten lead in place while sealing a joint in a cast iron pipe

JTU – Jackson Turbidity Unit – a quantitative unit of turbidity, originally based on the comparison of a liquid (such as water) with a suspension of a specific type of silica

Junction box – utility area where incoming current is connected in an electrical appliance

KW – kilowatt – a measure of the rate of supply of energy or power, equal to 1000 watts or 3412 BTU per hour

Kafer fitting – cast iron drainage pipe fitting with threaded-on hub used to attach to existing cast iron lines

Knockout Plug – PVC test plug

Kollar kap – styrofoam forms used to protect floor drains while concrete is being poured around them.

kPa – a metric unit for pressure – 100 kPa = one atmosphere

L tubing – an industry standard for copper tubing defined by the tube wall thickness and identified by a blue strip – a Type L copper tube wall is approximately 50% greater in thickness than Type M

LDO – Lint, Dust and Oil

LP – Liquid Propane – a fuel for gas water heaters

Laminar flow – streamlined flow of a fluid near a solid boundary

Laminated glass – glass that has been made by uniting layers of glass in order to strengthen it

Langelier index – a calculated number used to predict whether or not water will precipitate, be in equilibrium with, or dissolve calcium carbonate – it is sometimes erroneously assumed that any water that tends to dissolve calcium carbonate is automatically corrosive

Lateral sewage line – a sewage line that connects one sewage pipe with another

Laundry tub – a very deep sink used in a laundry room for soaking or washing clothing

Lav tube – water supply tube for a lavatory

Leach field – porous soil area, through which septic tank leach lines run, emptying the treated waste

Leach lines – pipes that carry effluent from the septic system out to the leach field

Leakage – loss of fluid, usually due to mechanical breakdown or gasket wear

Lean mixture – an air-gas mixture that contains more air than needed for complete combustion of the gas

Leader pipe – a pipe that carries rainwater to the ground or sewer

Length – a unit of linear measure for pipes (e.g. 10 ft)

Life cycle labs – a place where water heaters are tested at an accelerated rate to simulate life expectancies

Light duty – small commercial applications

Lime – the substance that settles on the bottom of a water tank – also known as sediment

Limit stop – faucet control unit used to adjust maximum water temperature

Lock nut – a nut fitted into a piece of pipe and screwed onto another pipe to join the two pieces

Low consumption toilet – a class of toilet designed to flush using 1.6 gallons of water or less – also known as a water-saving toilet

M tubing – an industry standard for copper tubing defined by the tube wall thickness and identified by a red stripe

MC Tank – acetylene tank holding 10 cu.ft. of gas, once used to fuel motorcycles and now used for plumbing

MCL – Maximum Contaminant Level – the maximum level of a contaminant allowed in water by law, which is based on potential health risks and what treatment is readily available

MHT – Male Hose Threads – the threads on the outside of a connection

MIPC – Male Iron Pipe Connection – standard external threads on pipe and fittings

MPN – Most Probable Number – term used to indicate the number of organisms that, according to statistical theory, would be most likely to produce the results observed in certain bacteriological tests – usually expressed as a number in 100 ml of water

Macerator – a device installed in a drain line between a toilet and the soil stack to reduce solids to liquid form

Magnesium – an element in the Earth’s crust that makes water hard when dissolved, causing scale and insoluble soap curds

Main – the primary artery of water supply in a drain system

Male fitting – fitting that is inserted into another fitting

Malleable fittings – fittings made of cast iron, a metal which is soft and pliable

Manganese – an element sometimes found dissolved in ground water that causes black stains

Manhole – access opening to a hole, usually with a cover, through which a person may enter a sewer, boiler, drain, etc. – it’s usually round to prevent the cover from falling into the opening

Mapp gas – a colourless, flammable gas made by combining liquefied petroleum gas with Methylacetylene-Propadiene – it is a stable, non-toxic fuel used for brazing and soldering

Meter tailpiece – an adapter connecting a water meter to the water supply line

Mission coupling – a neoprene flex coupling, connecting PVC to PVC, or clay to PVC

Mixing valve – mixes hot and cold water to achieve a specified delivery temperature

Monobloc faucet – a single-handle faucet, usually a lever

Multi-port valve – rotary type backwash valve, which can replace up to six regular gate valves

Multi-stage pump – a pump that has more than one impeller

Municipal water – water supplied by a city for public use

NOM – nominal – usually refers to the inside diameter of trade sizes of copper pipe

Natural gas – a colourless, odourless fuel (primarily consisting of methane) derived from the Earth – odours are added to aid in leak detection

Neo angle base – a shower base designed to allow a shower to be fitted in to a corner using minimal floor space

Negative pressure – less than atmospheric pressure

Nipple – a short length of pipe installed between couplings or other fittings

Nipple extractor – a tool used to unscrew sections of piping

No-hub connector – a connector for no-hub iron pipes consisting of a rubber sleeve and a stainless steel band secured by hose clamps

Non-ferrous – does not contain iron

Non-potable – unsuitable for drinking

O-Ring – round rubber washer used to create a watertight seal

OD – Outside Diameter – the diameter of a pipe measured from the outside edge

Oakum – loosely woven hemp rope that has been treated with oil or another waterproofing agent, which is used to caulk joints

Oil powered – a water heater that uses oil for its fuel source

Operating cost – the cost of running a water heater for a given time period

Orbital weld – a circumferential, full fusion weld used to join together two lengths of tubing

Organic matter – plant and animal substance created by living organisms

Outlet – the opening through which water exits the pump

Overflow tube – the vertical tube inside a toilet tank that directs water into the bowl in case the ballcock malfunctions

Ozone – an unstable form of oxygen, which can be generated by an electrical discharge through air or regular oxygen – it is a strong oxidising agent and has been used in water conditioning as a disinfectant

PB – polybutylene – a flexible type of tubing used in water supply systems

PE – polyethylene – a plastic material

PH – Potential Hydrogen – the hydrogen ion concentration of water measured on a scale of 0 to 14 (below 7 denotes acidity and above 7 indicates alkalinity)

PP – Polypropylene Pipe

PPM – Parts Per Million – a unit of measure for impurities in water

PR – Pressure Regulator – usually required if water pressure exceeds 80 PSI (pounds per square inch)

Packing nut – the nut that holds the stem of a faucet in position

Perfect vacuum – theoretically, space without matter in it

Perforated pipe – a pipe designed to discharge water through small nozzles, placed in a segment of its circumference for irrigation purposes

Petcock – a small faucet for draining liquids or relieving air pressure

Pickling – pipe immersed into an acid bath for removal of scale, oil or dirt

Pilot – a small burner used to ignite the main burner

Pin – external (male) threaded end of pipe

Pipe dope – substance applied to threaded fittings to create a watertight seal

Plumb – precisely vertical

Plumber’s helper – a plunger

Plumbing tree – prefabricated set of drain waste, vent and supply lines

Poppet – valve that rises perpendicularly to or from its seat

Pre-charged tank – a water storage tank pre-charged with air at factory, featuring a vinyl bag to separate water from air to prevent water-logging

Pressure head – pressure in a plumbing system – the unit of measure which is the vertical force exerted by water at a depth of one foot

Primary air – air which is mixed with gas before the gas leaves a burner port to burn – the ideal burning condition is generally 10 cubic feet of air per one cubic foot of gas

Priming jet – opening in bowl through which tank-supplied water flows – designed to propel waste up into trapway

Pumping level – the lowest water level reached during pumping operation

Purged line – a plumbing line in which the faucet has been opened and allowed to run for a specified length of time (usually between 1 and 5 minutes)

Quench – accelerated cooling, frequently in water (oil, water)

Quick closing valve – a valve or faucet that closes automatically when released manually or that is controlled by mechanical means for fast action closing

R & D – Reamed and Drifted – pipe commonly used in water wells with a heavy-duty coupling

RF – Recovery Factor – rating based on the efficiency of the product

Raw water – water supplied to the plant before any treatment

Recovery – the amount of water in gallons that can be heated in one hour (gph)

Recovery capacity – the amount of water in gallons per hour raised 100 degrees F at a given thermal efficiency and BTU per hour

Red water – water that is red or brown in colour due to the presence of precipitated iron and/or iron bacteria

Reducer – a fitting that connects pipes of different sizes together

Refill tube – the tube that directs water from a ballcock into the overflow tube to refill bowl after a siphon break

Relief valve – a valve that opens to relieve excess temperature

Reverse osmosis – a water treatment method whereby water is forced through a semi permeable membrane to filter out impurities

Rigid pipe – pipe designed to transmit the backfill load to the foundation beneath the pipe

Rim holes – a series of small holes in the underside of a toilet rim through which water flows to wash over the entire inner service of the bowl

Roman spout – deck-mounted faucet spout

Roof flashing – sheet metal installed at any break in a shingled roofline to prevent leaks around sewer vents

Rough-in – installation of the drain, waste, vent and supply lines in a structure to the proposed location of each fixture

Run – a complete or secondary section of pipe that extends from supply to fixture or drain to stack

STD – standard

Saddle tee – fitting that taps into the side of a pipe to make a quick connection to an existing line

Saddle valve – a valve mounted on a pipe run by a clamping device or saddle tee to supply water for a low-demand device

Safety shutoff valve – a device on a gas appliance that shuts off the gas supply to prevent a hazardous situation

Sag pipe – a section of a sewer line that is placed deeper in the ground than normal to pass under utility piping, waterways, rail lines, highways or other obstacles

Saponification –the process in which a fatty acid is neutralised with an alkali or base to form a soap

Scale – a thin layer of calcium on the interior of a tank that may prevent heat transfer

Schedule – numbers assigned to different wall thicknesses of pipe (e.g. sch 40)

Scupper drain – a drain on a roof or deck that allows rainwater to drain off

Sediment – the substance that settles on the bottom of a tank, also known as lime

Serial / model – a permanent information plate attached to a major home appliance detailing the product model and serial number, plus information about wattage or industry standard requirements

Siphon – a pipe connecting two canals, through which water flows over a high point of gravity

Sleeve – pipe that is passed through a wall for the purpose of inserting another pipe through it

Slip joint – a connection made with compression fittings

Soft water – water that has a low calcium and magnesium content

Solder – a metal alloy that is melted to create a fused joint between metal pieces

Spark test – a test procedure to evaluate the integrity of the glass lining

Specific gravity – the ratio of the weight of a specific volume of substance compared to the weight of the same volume of pure water at 4 degrees Celsius

Stem – part of the faucet that holds the handle on one end and the washer on the other

Straight cross – fitting that connects four pipes of the same diameter

Street ell – a 90 degree elbow joint with a hub on one end and male threads on the other used to make an angled connection between pipe or tubing and a fitting with a hub

Stud guard – short band of metal attached to wall studs to prevent nails from penetrating and damaging pipes

Supply kit – a kit of all parts needed to fit a faucet or toilet to the pipes coming out of a wall, usually containing stop valves, water connectors and escutcheons

Supply stop – the valve that controls water supply to a toilet

Sweep – a drain ell fitting with a long radius that allows for smooth passage of waste

Swing joint – a flexible sprinkler connection made by connecting three threaded elbow fittings together

TBE – Threaded Both Ends

T&C – Threaded and Coupled

Tailpiece – section of pipe that runs between a fixture outlet and the trap

Tap adapter – fitting with one plain end and one threaded female end

Tap tee – cast iron tee with a threaded female side inlet

Tee – T-shaped fitting with three openings that allow another pipe to be attached at a 90 degree angle

Teflon tape – a fluorocarbon polymer with non-sticking properties used to wrap pipe threads to seal a joint

Test plug – a rubber plug used to seal off sections of pipe to test for leaks

Thermal efficiency – ability to transfer and absorb heat from fuel sources into water

Throat-plate – the underside portion of some faucet spouts that also use a top shroud to cover an assembled faucet waterway – the throat-plate is only visible when viewed from a very low angle

Threaded – a spiral ridge on a screw, nut or bolt

Trap – curved section of drain line that prevents sewer odours from escaping into the atmosphere – all features that have drains must have a P-trap installed, whilst toilets will have S-traps

Trap arm – the waste arm portion of a drainage trap

Trap dip – the U-bend portion of a drainage trap

Trap drain – a flex adapter to connect drain pipes

Trap primer – a small feeder line connecting the cold water line directly to the drainage trap – it releases a small amount of water to the trap if it runs dry to maintain the water seal

Trap seal – height of water in a toilet bowl at rest, providing a water seal to prevent sewer gases entering the home

Trap weir – an interior projection in the outlet side of a trap to aid in maintaining a water seal

Tuberculation – the process in which blister-like growths of metal oxides form in pipes as the result of corrosion of the pipe metal – iron oxide tubercles often develop over pits in iron or steel pipe and can seriously affect water flow

Type M tube – an industry standard for copper tubing defined by the tube wall thickness and identified by a red stripe

Tyseal gasket – gasket for joining SV cast iron pipe into a hub

U-bend – a section of a waste pipe that is shaped like the letter U, which stops smells coming back into the property – Battersea-based plumbing company U-Benders created a pun of the word to form their popular brand’s name, attracting an array of celebrity customers, including Julian Clary

ULF – Ultra Low Flush – a widely used description of toilets that use 1.6 gallons per flush or less

UNC – Unified National Coarse Thread – standard type of stiff, straight thread used on fittings, nuts and bolts

UNF – Unified National Fine Thread – standard type of thin, straight thread used on fittings, nuts and bolts

Ultra coil – double wall heat exchanger

Uniformity coefficient – a measure of the variation in particle sizes of ion exchange resins and filter media – it is defined as the ratio of the size that has 60 per cent of the material finer than itself to the size of the particle that has 10 per cent finer than itself

Union – three piece fitting that joins two sections of pipe but allows them to be disconnected without cutting the pipe, primarily used with steel pipe

Urinal – plumbing fixture that receives liquid body waste and conveys the waste through a trap seal into a gravity drainage system

Urinal strainers – domed metal piece fastened to the bottom of a urinal to prevent debris from blocking the trapway of the unit

Usable storage – percentage of hot water that can be drawn from a tank before the temperature drops to a point that it is no longer considered hot

Utility sink – deep fixed basin supplied with hot and cold water, used for rinsing mops and the disposal of cleaning water

V-clip – a clip shaped like the letter ‘V’ used on a lavatory drain lift linkage assembly to easily adjust the connection of the drain to the lift rod

Vacuum breaker – an anti-siphon device that prevents backflow of contaminated water into the water supply system

Valve – a device that regulates the flow of fluid

Valve seat – the non-moving part of a valve – water flow is stopped when the movable element comes into contact with the valve seat

Valve seat wrench – hexagonal end wrench inserted into the hexagonal opening of a valve seat for installation or removal

Velocity head – amount of energy required to accelerate water to a given speed, expressed in feet per head

Vent – a pipe that allows air into a drain system to balance air pressure and to prevent water in the traps from being siphoned off

Vent header – a vent pipe into which several vents connect – this leads to the vent stack and out of the building

Vent stack – upper portion of the soil stack above the top fixture, through which gases and odours escape

Venting materials – a number of materials are used for venting, including PVC and metal

Venturi – a short tube with a tapered constriction in the middle that causes an increase in the velocity of fluid flow and the corresponding decrease in fluid pressure that is used for creating suction in a vacuum pump

Viscosity – resistance of fluid flow due to internal forces and friction between molecules, which increases as its temperature decreases

Vitreous surface – material on some plumbing fixtures that is derived from or consists of glass, is translucent and low on porosity

Vitreous China – ceramic materials fired at a high temperature to form a non-porous body, yielding exposed surfaces coated with ceramic glaze, and used for bathroom fixtures such as toilets

Volatile – capable of vaporisation at a relatively low temperature

Volumetric – refers to measurement by volume rather than weight

Voral tube – flexible steel hose used for handheld shower sprays

WC – Water Closet – toilet

Wall thickness – the thickness of the tubing wall

Waste arm drain – an extension pipe usually used to extend a sink drain into a wall

Waste and overflow drain – an assembly for a bathtub – the outlet at the top removes overflow water during tub filling and the drain at the bottom removes wastewater when the tub is drained

Waste plug – drain stopper on a bathtub drain

Waste shoe – bathtub drain assembly

Waste stack – main vertical pipe in a drainage system, extending one or more stories

Water hammer – loud banging noise caused by hydraulic shock that occurs when water supply is suddenly shut off, resulting in water moving against the side of containing pipe

Water hammer arrestor – device installed near fixture to absorb hydraulic shock of abrupt water shutoff

Water Horse Power (WHP) – calculated horse power produced by pump using formula WHP = head x gpm/3960

Water service pipe – pipe from the water main

Water spot – water surface in the toilet bowl once the flush is completed

Water table – level below the earth’s surface at which the ground becomes saturated with water

Waterway fitting – a channel through which water can flow, connecting water heater to inlet and outlet lines

Wave washer – a washer, common in drain linkages, which provides pressure against a ball or other mechanism even when the nut is not fully tightened

Weak well – application occurs when the pump lowers the water level in the well faster than the well can replenish itself

Weir – long notch with horizontal edge used to measure the quantity of flowing water

Well casing – steel or plastic pipe inserted into a drilled well to prevent dirt and debris from contaminating the water

Well point – pipe fitted with driving point and a fine mesh screen used to remove underground water

Wet vent – drain or waste pipe that also acts for one or more fixtures on the same line

Working pressure – maximum pressure of the operating system permissible

Wrought copper fittings – plumbing fittings used to connect copper tubes made of mechanically worked and toughened copper

Wye – Y-shaped fitting with three openings used to create branch lines and allows one pipe to be joined to another at a 45-degree angle

XH – Extra Heavy

XL – Extra Large

XLG – Extra Long

XS – Extra Small

Yellow tipping – a flame condition caused by a severe reduction in primary air – the yellow colour is caused by glowing carbon particles in the flame and can be corrected by the injection of more primary air

Yoke – Usually a brass casting that holds both the hot and cold valves and the mixing chamber for the water – may also refer to an assembly of copper or other metal which serves the same function

Yoke vent – pipe connecting upward from a soil or waste stack to a vent stack to prevent pressure changes in the stacks

Zeolite – a group of hydrated sodium aluminosilicates, either natural or synthetic, with ion exchange properties

Zone of aeration – the layer in the ground above the water table where the available voids are filled with air – water falling on the ground percolates through this zone on its way to the aquifer

Zone of saturation – the layer in the ground in which all of the available voids are filled with water