Plumbing Glossary: A Detailed List of All Plumbing
Terms and Definitions
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manner cost effective.
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[A]
ABS:
(Aristocraft bristone styrine) A rigid black
plastic piping used for waste, vent, and drain lines.
Access Panel:
An opening in the wall or ceiling near the
fixture that allows access for servicing the plumbing/electrical
system.
Adaptor:
A fitting that unites different types of
pipe together, for example: ABS (Aristocraft bristone styrine)
to cast iron pipe.
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.
Airbreak:
An airbreak is a physical seperation which
may be a low inlet into the indirect waste receptor from the
fixture, appliance, or device indirectly connected.
Air Lock:
Blockage in the flow of liquid, esp. on
the suction side of a pump caused by an air bubble in the line.
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.
[B]
Backflow:
Backflow is the flow of water or other liquids,
mixtures, or subsatnaces into the distributing pipes of a potable
supply of water from any sources other than its intended source.
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 sink.
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.
BTU (British Thermal Unit):
A unit of heat energy required to raise
the temperature of 1 lb. of water 1 degree Fahrenheit.
Building:
A building is a structure built, erected,
or framed of component structural parts designed for housing,
shelter, enclosure, or support of persons, animals, or property
of any kind.
[C]
Catch 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
faucet holes.
Cesspool:
A cesspool is a lined excavation in the
ground which receives the discharges of a drainage system or
part thereof, so designed as to retain the organic matter and
solids discharging therein, but permitting the liquids to seep
through the bottom and sides.
Check Valve:
A type of backflow preventer installed in
a pipe run that allows water to flow in only 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.
Cleanout Plug:
A plug in a trap or drain pipe that provides
access for the purpose of clearing an obstruction.
Closet:
A term used for a Toilet.
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 drain.
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 water, sometimes referred to as a ballcock.
Common Vent:
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
elements.
CPVC (Chlorinated Polyvinyl Chloride):
Rigid plastic pipe used in water supply
systems, where code permits.
Culvert:
A pipe-like construction of concrete that
passes under a road to allow drainage.
[D]
Desanco 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 inlet.
Diverter:
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.
DWV:
Abbreviation for Drain, Waste
and Vent.
[E]
E Coli:
The common abbreviation of Escherichia Coli.
One of the members of the coliform groups of bacteria indicating
fecal contamination.
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.
Elbow:
A pipe fitting with two openings that changes
the direction of the line. Also called an ell. It comes in
a variety of angles, from 22 1/2° to 90°.
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).
[F]
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.
Fixture:
In plumbing, the devices that provide a
supply of water and/or its disposal, e.g. sinks, tubs, toilets.
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 as needed.
Floor Flange:
A fitting that connects a toilet to a floor
drain.
Flushometer:
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.
Footprint:
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.
[G]
Gas Cock:
Plug 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 Water:
Waste water from sinks, showers, and bathtubs,
but not toilets.
[H]
Horizontal 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 it leaves.
Hose Bibb:
An outdoor faucet, also used to supply washing
machines.
House Trap:
U-shaped fitting with two adjacent cleanout
plugs visible at floor level if main drain runs under floor.
Hubless (No-Hub):
Cast iron drainage pipe with neoprene gaskets
and clamps.
Hydronic:
System of forced hot water.
[I]
I.D.:
Abbreviation for inside diameter. All pipes
are sized according to their inside diameter.
Indirect 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 coil.
[J]
Jet:
An orifice or other feature of a toilet
that is designed to direct water into the trapway quickly to
start the siphon action.
Johnni-bolts:
Closet bolts, used to mount toilet bowls
to the closet flange.
[K]
Kafer Fitting:
Cast iron drainage pipe fitting with threaded-on
hub used to attach to existing cast iron lines.
Knockout Plug:
PVC test plug.
[L]
Lavatory (Lav):
A fixed bowl or basin with running water
and drainage for washing. Also reffered to as a restroom or
a bathroom.
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.
[M]
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.
[N]
Nipple:
A short length of pipe installed between
couplings or other fittings.
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.
[O]
O.D.:
Abbreviation for Outside Diameter.
O-Ring:
Round 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.
[P]
Packing:
Fibrous material that is used on faucets
to prevent leaks.
Packing Nut:
Nut that holds the stem of a faucet in position & holds
the packing material.
PB (Polybutylene):
Flexible plastic tubing used in water supply
systems where allowed by code.
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 valve.
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.
PVC (Polyvinyl Chloride):
A rigid white or cream-colored plastic pipe
used in non-pressure systems, such as drainage, waste, and
vent systems.
[R]
Rated 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
fit properly.
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
sizes together.
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.
Revent:
Pipe installed specifically to vent a fixture
trap. Connects with the vent system above the fixture.
Reverse Trap Water Closet:
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 vents,
fluepipes.
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.
[S]
Saddle 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 Fitting:
Fitting that joins the assorted pipes in a
drain, waste and vent system; designed to allow solid material
to pass through without clogging.
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 Call: A communication
to Veterans that is handled immediately in a professional manner
cost effective.
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 Closet:
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 and
chisel.
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 system.
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]
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 opening.
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 valve.
Tap Tee:
Cast iron tee with a threaded female side
inlet.
Tee:
A T-shaped fitting with three openings used
to create branch lines.
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.
[U]
Uni-flex:
One 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 DWV system.
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.
[V]
Vacuum Breaker:
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 building.
Vent Stack:
Upper portion of the soil stack above the
topmost fixture through which gases and odors escape.
Vent System:
A vent is a pipe or pipes instalto provide
a flow or air to or from a drainage system to provide a circulation
of air within such system to protect trap seals from siphonage
and back-pressure.
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 vacuum pump.
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 lavatories.
[W]
Washdown 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.
Wet Vent:
A wet vent is a vent that also serves as
a drain.
Widespread:
A style of bathroom lavatory faucet having
separate spout and handles, usually 8" from center of handle
to handle.
WYE:
A Y-shaped fitting with three openings used
to create branch lines.
[Y]
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:
A yoke vent is a pipe connecting upward
from a soil or waste stack to a vent stack for the
purpose of preventing pressure changes
in the stacks.