Click on a letter below to jump to the definition you need. -
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - R - S - T - U - V - W - Y
ABS: Aristocraft bristone
styrine, a rigid black plastic pipe used for drain,
waste, and vent lines.
Aerator: A device screwed into the end of a faucet
spout that mixes air into flowing water, and controls
flow to reduce splashing. It sometimes contains a baffle
to reduce flow to 2.5 gpm.
Air Lock : Blockage in the flow of liquid, esp. on the
suction side of a pump caused by an air bubble in the
Angle Stop: A shutoff valve between
the water pipes and a faucet. Its inlet connects to the
water supply pipe in a wall, and its outlet angles up
90 degrees toward the faucet. These are usually used
to shut off water to a fixture in case of an emergency
repair rather than daily usage.
Anode Rod: A sacrificial rod installed
in a water heater that protects the tank from corrosion,
helping to extend the life of the tank.
Anti-Siphon: Preventive device for
the backflow of liquid into a system. Used on sprinkler
systems to prevent water from trickling back into the
supply that is feeding it.
BTU: British Thermal Unit - A unit of heat energy required
to raise the temperature of 1 lb. of water 1 degree Fahrenheit.
Back Flow Preventer: A device to prevent water from
traveling from one system back into any part of the main
distribution system, usually by siphoning, esp. into
a potable water supply. This is generally required for
sprinkler systems, handheld showers, pullout faucet spouts,
kitchen sprayers, etc.
Back Pressure: Pressure that resists the flow of fluid
in a piping system.
Backwater Valve: Sewer line valve that prevents sewage
from flowing back into the house.
Ball Check Valve: A valve that uses a ball to seal
against a seat to stop flow in one direction.
Ballcock: The fill valve that controls
the flow of water from the water supply line into a gravity-operated
toilet tank. It is controlled by a float mechanism that
floats in the tank water. When the toilet is flushed,
the float drops and opens the ballcock, releasing water
into the tank and/or bowl. As the water in the tank is
restored, the float rises and shuts off the ballcock
when the tank is full.
Basin Wrench: A wrench with a long handle with jaws
mounted on a swivel that allows the jaws to reach and
handle nuts to fasten faucets to a previously installed
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 water is introduced,
it expands to grip the pipe, and releases pulsating bursts
of water through the nozzle, forcing water through the
pipe to clear the obstruction.
Branch: Any part of a drain system other than the main,
riser, or stack.
Branch Vent: A vent connecting one or more individual
vents with a vent stack.
Basin: Large underground container, with a grate on the top,
for collection of storm water run-off. It catches or
collects dirt and other debris and prevents them from
polluting streams and lakes.
Centerset: Style of bathroom faucet having combined
spout and handles, with handles 4 inches apart, center-to-center.
Also a single-handle faucet installed on 4 inches center-to-center
Check Valve: A type of backflow preventer installed
in a pipe run that allows water to flow in only one direction.
Circuit Ven: 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
Cistern: Rainwater storage tank, often underground.
Cleanout Plug: A plug in a trap or drain pipe that
provides access for the purpose of clearing an obstruction.
Closet Auger: A flexible rod with a curved end used
to access the toilet's built-in trap and remove clogs.
Closet Bend: A curved fitting mounted immediately below
the toilet that connects the closet flange to the toilet
Closet Flange: An anchoring ring that attaches to the
closet bend and secured to the floor. The heads of closet
bolts, used to secure the toilet in place, insert into
slots in the closet flange.
Cock: A faucet or valve for regulating the flow of
Common Ven: Building drain system vertical vent which
connects two or more fixture branches on the same level.
Compression Fitting: A kind of tubing or pipe connection
where a nut, and then a sleeve or ferrule is placed over
a copper or plastic tube and is compressed tightly around
the tube as the nut is tightened, forming a positive
grip and seal without soldering. Also a flexible connector
that has a nut and gasket designed to attach directly
to an SAE standard compression thread, without the use
of a sleeve or ferrule.
Compression Valve: A type of valve that is often used
for water faucets. It is opened or closed by raising
or lowering a horizontal disk by a threaded stem.
Coupling: Vent pipe hood, which protects it from the
Culvert: A pipe-like construction of concrete that
passes under a road to allow drainage.
Fitting: A type of compression adapter that connects
tubular brass fittings to PVC pipe.
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. This eliminates the
possibility of debris build-up within the valve.
Dip Tube: Tube inside the water heater that sends cold
water to the bottom of the tank.
Direct Tap: Clamping device that allows a branch line
to be drilled and tapped off a main line.
Discharge Tube: Outlet tube that connects a disposer
or sump pump to the drain line.
Disposal Field: A series of trenches conveying the
effluent from the septic tank laid in such a manner that
the flow will be distributed with reasonable uniformity
into natural soil.
Dishwasher Tailpiece: A flanged adapter connecting
a basket strainer to the drainpipe with a dishwasher
Diverte: Valves which direct water to various outlets.
They are used in showers, tubs, bidets, and sinks.
Drip Leg: A stub end pipe placed at a low point in
the gas piping to collect condensate and permit its removal.
Drum Trap: An obsolete, non-vented drain lead or cast
iron canister trap formerly used in sewer lines.
Duo Valve: A twin valve (hot & cold) with a single
on/off lever used for washing machine boxes.
Coli: The common abbreviation of Escherichia Coli. One of the
members of the coliform groups of bacteria indicating
Earthquake Strap: A metal strap used to secure a water
heater to the house frame or foundation.
Efficiency: A product's ability to utilize input energy,
expressed as a percentage.
Effluent: Septic system liquid waste.
Escutcheon: A decorative metal flange or trim shield
beneath a faucet handle that covers the faucet stem and
the hole in the fixture or wall.
Expansion Tank: A tank designed to absorb excess pressure
due to thermal expansion (e.g. closed system).
Fall/Flow: The proper slope or pitch of a pipe for adequate drainage.
Female Fitting: A fitting that receives a pipe or fitting.
A fitting into which another fitting is inserted.
Finish Plumbing: Installation of plumbing fixtures
to make the system usable.
Flapper Valve: The part on the bottom of the toilet
tank that opens to allow water to flow from the tank
into the bowl.
Float Ball: The floating ball connected to the ballcock
inside the tank that rises or falls with changing water
levels in the tank, and actuates or shuts off the ballcock
Floor Flange: A fitting that connects a toilet to a
Flushomete: Toilet valve that automatically shuts
off after it meters a certain amount of water flow.
Flushometer Tank System: Toilet flushing system that
uses supply water pressure to compress water to provide
a pressurized flush as opposed to a gravity flush.
Flux: Paste applied to copper pipes and fittings before
soldering to help the fusion process and prevent oxidation.
Footprin: The area of floor space taken up by a water
heater or other appliance.
French Drain: A covered ditch containing a layer of
fitted or loose stone or other pervious material.
valve installed the main gas line and an appliance.
Gas Control: Device used to regulate gas pressure on
a water heater.
Gate: A device that controls the flow in a conduit,
pipe, or tunnel.
Gate Diverter: The pop-up lever on a tub faucet that
activates the diverter valve.
Gravity Operated Toilet: A toilet that relies on the
natural downward pressure of water in a toilet tank to
flush the toilet effectively.
Gray Wate: Waste water from sinks, showers, and bathtubs,
but not toilets.
Branch: Lateral drain pipes that run from plumbing fixtures to
the waste stack in a building or in the soil.
Horizontal Run: The horizontal distance between the
point where fluid enters a pipe and the point at which
Hose Bibb: An outdoor faucet, also used to supply washing
House Trap: U-shaped fitting with two adjacent cleanout
plugs visible at floor level if main drain runs under
Hubless (No-Hub): Cast iron drainage pipe with neoprene
gaskets and clamps.
Hydronic: System of forced hot water.
Wastes: Waste pipe used to convey gray water by discharging it
into a plumbing fixture such as a floor drain.
Instantaneous Water Heater: A type of water heater
that heats water as it flows through a heat exchanger
orifice or other feature of a toilet that is designed
to direct water into the trapway quickly to start the
Johnni-bolts: Closet bolts, used to mount toilet bowls
to the closet flange.
Plug: PVC test plug.
(Lav): A fixed bowl or basin with running water and drainage
for washing. Bathroom sink.
Leach Field: Porous soil area, through which septic
tank leach lines run, emptying the treated waste.
Leader: Pipe carrying rainwater to the ground or sewer.
Lock Nut: Nut fitted into a piece of pipe and screwed
onto another pipe to join the two pieces
Main: The primary
artery of supply of the water supply or drain system
in which all the branches connect. In the case of drains,
known as the Main Vent.
Male Threads: Threads on the outside of pipes and fittings.
Malleable Fittings: Fittings made of metal which is
soft and pliable.
Manifold: A fitting that connects a number of branches
to the main; serves as a distribution point.
Mechanicals: The wiring, plumbing and heating and cooling
systems in a building; also the components with moving
parts such as furnaces, plumbing fixtures, etc.
Multi-Stage Pump: A pump that has more than one impeller.
Nipple: A short length of pipe installed between couplings or
No-Hub Connector: A connector for no-hub iron pipe
consisting of a rubber sleeve and a stainless steel band
secured by hose clamps. A variation, a neoprene sleeve
with two adjustable steel bands, is used for connecting
dissimilar materials, as when connecting new plastic
pipe to an existing cast-iron drainpipe.
rubber washer used to create a watertight seal, chiefly
around valve stems.
Oakum: Loosely woven hemp rope that has been treated
with oil or other waterproofing agent; it is used to
caulk joints in a bell and spigot pipe and fittings.
Outlet Sewer: Pipe section in a septic system which
runs between the septic tank and the drainage field.
chloride. A rigid white or cream-colored plastic pipe
used in non-pressure systems, such as drainage, waste,
and vent systems.
Packing: Fibrous material that is used on faucets to
Packing Nu: Nut that holds the stem of a faucet in
position & holds the packing material.
Peak Hour Demand: Time when the largest demand for
hot water is needed.
Pipe Dope: Slang for pipe-joint compound. Substance
applied to threaded fittings to create a watertight seal.
Pitch: Downward slope of a drain pipe in the direction
of the water flow.
Plumb: Precisely vertical. Also to test for, or to
make vertical. Also to perform plumbing work.
Plumber's Putty: Pliable, popular putty used to seal
joints between drain pieces and fixture surfaces.
Plumbing Tree: Prefabricated set of drain waste, vent,
and supply lines
Pop-Up Drain: Type of drain assembly for lavatory and
bath. When a lavatory lift rod or bath overflow plate
lever is lifted, the pop-up drain closes so the lavatory
or tub retains water.
Port: An opening in a burner head through which gas
or an air-gas mixture is discharged for ignition.
Positive Displacement Pump: Called a PD pump. Gear,
sliding vane, progressive cavity, lobe etc. the capacity
determined by the pump speed. The maximum head is determined
by the horsepower available and the casing strength.
Pressure Balance Valve: Shower mixing valve that automatically
maintains balance between incoming hot and cold water
supplies by immediately regulating fluctuations in pressure.
As a result, temperature remains constant, though the
outlet pressure may drop. Also known as an anti-scald
Pressure Tank: Device used to pump water from a well.
Pressure Tubing: Tubing used to conduct fluids under
pressure or at elevated temperatures or both, and produced
to stricter tolerances than pipe.
Storage Volume: Quantity of water stored in a tank.
Reamer: A grinding tool used to level or remove burrs
from valve seats in faucets so that the valve stem will
Recovery Capacity: The amount of water in gallons per
hour raised 100 degrees F at a given thermal efficiency
and BTU per hour input.
Reducer: A fitting that connects pipes of different
Return Circulation System: Tempered water from or near
the point of usage which eliminates waste of hot water
used for long runs and adds storage to the system.
Reven: Pipe installed specifically to vent a fixture
trap. Connects with the vent system above the fixture.
Reverse Trap Water Close: A water closet having a
siphonic trapway at the rear of the bowl, and integral
flushing rim and jet.
Rigid Pipe: Pipe designed to transmit the backfill
load to the foundation beneath the pipe. Rigid pipe must
be supported on the bottom portion of the pipe.
Rim Holes: A series of small holes in the underside
of a toilet rim, around the circumference of the bowl.
Incoming water flows down into the bowl through these
holes, creating a rinse effect or wash over the entire
inner surface of the bowl.
Riser: A vertical metal or plastic tube or assembly
that connects a faucet to the water supply stop valve.
Usually made of copper. Metal Flex Risers are corrugated
to facilitate bending. Also a supply line that rises
from one story to the next.
Roof Flashing: Sheet metal installed at any break in
a shingled roofline to prevent leaks. Also around sewer
Rough-In: Installation of the drain, waste, vent, and
supply lines in a structure to the proposed location
of each fixture.
Rough-In Dimensions: The distance from a finished wall
or floor to the center of the waste or supply opening
or mounting holes on a plumbing fixture.
Run: A complete or secondary section of pipe that extends
from supply to fixture or drain to stack.
Valve: A valve mounted on a pipe run by a clamping device, or
fitting that taps into the side of a pipe, used to make
quick connection to an existing line to provide a water
supply for a low-demand device.
Sanitary Sewer: House drain that carries wastewater
away from the house to a sewer system or septic tank.
Self-Rimming Sink: Sink with no metal ring that has
a built-in lip of the same material which supports it
in the vanity top.
Service Entrance: Pipe connecting the water company
piping to the water meter.
Setting: Pumps' vertical distance in feet from the
top of the well to the top of the pump.
Shroud: Color-matched component under a wall-mount
lavatory that covers the drain outlet for aesthetic purposes.
Siphon-Vortex Water Close: A toilet having a trapway
at the rear of the bowl, integral flushing rim, and a
water supply system with or without a jet, which does
not feed directly into the trap.
Sleeve: Pipe which is passed through a wall for the
purpose of inserting another pipe through it.
Slip Joint: A connection made with compression fittings.
Soil Stack: Largest vertical drain line to which all
branch waste lines connect. This line carries waste to
the sewer line.
Solder: Metal alloy that is melted to create a fused
joint between metal pieces. Also the act of melting solder
into the joint.
Spud: A threaded opening on the water heater tank.
Also a tool for digging having characteristics of a shade
Stack: The vertical main in the drain, waste, and vent
system, extending one or more stories.
Stand Pipe: Open vertical pipe that receives water
from a washing machine. Also the vertical pipe run supplying
water to a fire sprinkler system; also large vertical
pipe into which water is pumped in order to produce a
desired pressure; a high vertical pipe or reservoir that
is used to secure a uniform pressure in a water-supply
Static Lift: The vertical distance between source and
discharge water levels in a pump installation.
Stop Valve: The shutoff valve under sinks and toilets.
Allows water supply to be cut off to one fixture without
affecting the water supply to other fixtures.
Straight Cross: Fitting that connects four pipes of
the same diameter.
Sump: A pit or pool for draining, collecting, or storing
water. A chamber which provides water to the pump.
Sweating: Slang term for soldering. Also formation
of condensation on the outside of pipes or toilet tanks.
T & P
Valve: Temperature & pressure relief valve. A safety device
used to expel excess pressure or heat from inside a tank.
Tailpiece: Section of pipe that runs between a fixture
outlet and the trap.
Tail Pipe: The pipe added below the jet assembly, in
a weak well application.
Tank: Fixture reservoir for flush water. On a conventional
toilet, the ballcock, flush valve, and trip lever are
installed in the tank. A tank lid closes the top tank
Tank Cross: A double-tee-shaped fitting installed between
a shallow well pump and the bladder tank with integrated
valve and gauge fittings, and an outlet for a pressure-relief
Tap Tee: Cast iron tee with a threaded female side
Thermocouple: Small electric generator. Electron flow
between the hot junction of 1200 degrees F and cold junction
of 600 degrees F creates millivoltage.
Thermostatic Valve: Pressure-balancing shower mixing
valve with automatic temperature control. When temperature
or pressure fluctuations occur at the water inlets, a
thermal actuator adjusts the hot and cold ratio to maintain
the original temperature setting.
Trap: Curved section of drain line that prevents sewer
odors from escaping into the atmosphere. All fixtures
that have drains must have a "P" trap installed. A toilet
is the only plumbing fixture with an "S" trap.
Trap Arm: The waste arm portion of a drainage trap.
Trap Dip: The U-bend portion of a drainage trap.
Trap Primer: A small feeder line connecting the cold
water line directly to the drainage trap, which releases
a small amount of water to the trap should it run dry
to maintain the water seal.
Trap Seal: Height of water in a toilet bowl "at rest.".
It provides the water seal which prevents sewer gases
from entering the home. It is measured from the top of
the dam down to the inlet of the trapway. Also referred
to as deep seal.
Trapway: Channel in a toilet that connects the bowl
to the waste outlet. It is where the siphonic action
takes place. The trapway is measured in terms of the
largest diameter ball which can pass through it. Also
called the passageway.
Trip Lever: Flush handle and actuating arm on a toilet
tank. Also the lever that opens and closes the drain
on the bathtub waste and overflow.
piece stop and riser combination. One-piece supply.
Union: Three piece fitting that joins two sections
of pipe, but allows them to be disconnected without cutting
the pipe. Used primarily with steel pipe; never in a
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.
Breake: An anti-siphon device that prevents the backflow of contaminated
water into the water supply system.
Valve Dressing: Resurfacing a worn valve seat with
a special tool. Stops leaks by providing a smooth sealing
surface. Applies only to older compression style faucets.
Valve Seat: The non-moving part of a valve. Water flow
is stopped when the moveable portion of the valve comes
in contact with the valve seat.
Vent: A pipe that allows air into a drain system to
balance the air pressure, preventing water in the traps
from being siphoned off.
Vent Header: A vent pipe into which several vents connect.
The vent pipe leads to the vent stack and out of the
Vent Stack: Upper portion of the soil stack above the
topmost fixture through which gases and odors escape.
Venturi: A short tube with a tapered constriction in
the middle that causes an increase in the velocity of
flow of a fluid and a corresponding decrease in fluid
pressure and that is used for creating a suction in a
Viscosity: The resistance of fluids to flow, due to
internal forces and friction between molecules, which
increases as its temperature decreases.
Vitreous China: Ceramic materials fired at high temperature
to form a non-porous body, having exposed surfaces coated
with ceramic glaze fused to the body. This is used to
form bathroom fixtures such as toilets, bidets, and lavs.
Water Closet: Water closet having a siphon trapway at
the front of the bowl, and integral flushing rim.
Waste Arm: Drain extension pipe, usually to extend
a sink drain into a wall.
Waste & Overflow: Drain assembly for a bathtub.
The outlet at the top removes the overflow water during
tub filling and the drain at the bottom removes wastewater
when the tub is drained.
Widespread: A style of bathroom lavatory faucet having
separate spout and handles, usually 8" from center of
handle to handle.
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.