Plumbing Glossary

Plumbing Glossary 


A glassy, thermoplastic material that is vacuum-formed to cast and mold shapes to create fixtures.
ADA: (Americans with Disabilities Act) A government criteria mandating how plumbing faucets & fixtures must be constructed in order to serve the needs of disabled people.
AMSE: American society of mechanical egineers. Sets stress, pressure and tolerance standards for manufactured products.


A raised integral portion of a wall mount sink or lavatory located at the rear to protect the wall.


Basket shaped strainer with holes and a slot that fits the kitchen sink drain allowing water to run out while catching food or other solids. Can also be closed to fill the sink with water.


Heavy metal covered with a porcelain enamel coating formed by casting on molds to make fixtures such as sinks, tubs and lavatories.


A style of bathroom lavatory faucet that has a combined spout and handles. Center of handles are 4" apart. Also a single handle faucet installed on 4" center-to-center faucet holes.

CHECK VALVE: A type of backflow preventer installed in a pipe that allows water to flow in only one direction.  


A kind of tubing or pipe connection where a nut and 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.


Straight, sleeve-like fitting with female connections at both ends.


Valves which direct water to various outlets. They are used in showers, tub & shower combinations, bidets, roman tub fillers and kitchen faucet sprayers.

ELBOW: Angled fitting with female connections at both ends. Also known as an “ell”.

FEMALE IPS (FIP): (Female Iron Pipe) Standard internal threads on pipe fittings.

FIRECLAY: A variation of vitreous china having greater amounts of quartz and feldspar in the clay material beneath the vitreous surface. Fireclay is heavier (30%), denser, and thicker than regular clay. These properties insure smooth, flat surfaces on large fixtures which is not achievable with standard vitreous china.

GPM: (Gallons Per Minute) The rate of water flow by which faucets and showerheads are measured and regulated.


(Inside Diameter) All pipes are sized according to their inside diameter. IPS:  (Iron Pipe Size) Standard pipe threads. Female IPS is internal pipe threads, male IPS are external pipe threads. Also known as “NPT” or “NPS”

MALE IPS (MIP): (Male Iron Pipe) Standard external threads on pipe and fittings.

MIXING VALVE: Mixes hot and cold water to achieve a specified delivery temperature.

MOUNTING FRAME: External mounting means used to install sinks which have no integral provision.

NIPPLE: A short length of pipe installed between couplings or other fittings

NOMINAL SIZE: Size used for identification only; not literal dimensions.

O.D.: (Outside Diameter) The diameter of a pipe measured from the outside edge

POWDER COAT: A technique for applying paint to metal surfaces. The metal is covered with a powder of dry paint particles and is baked in an oven. This causes the powder to melt and harden into a tough, colorful finish.

PSI: (Pounds Per Square Inch) A means of measurement used to determine pressure within contained area.

PULL-OUT SPRAY: Single-control kitchen faucet which offers a retractable hose and sprayhead to be used for food preparation and cleaning.

PVD: (Physical Vapor Deposition) A modern plating process used mostly with polished brass or gold finishes on faucets. Vaporized zirconium reacts with nitrogen and another special gas to form a durable plated surface which will not tarnish or discolor.

RISER: A vertical metal or plastic tube or assembly that connects a faucet to the water supply stop valve. Usually made of copper.


Installation of the drain, waste, vent, and supply lines in a structure to the proposed location of each fixture.

SELF-RIMMING: A style of bathroom lavatory or kitchen sink with a rolled and finished edge, or rim. The fixture installs on top of a counter without the need for a metal sink rim.

STOP: The shutoff valve under sinks and toilets. Allows water supply to be cut off to one fixture without affecting the water supply to the entire house or building. 

TEE: T-shaped fitting with three openings that allow another pipe to be joined at a 90 degree angle, used to create branch lines.

 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.


Refers to the outside decorative covering of a faucet rough-in valve. Includes items such as the showerhead, tub spout, handles, etc. The trim is the parts you can see when looking at a faucet.

UNDERMOUNT: A style of sink which is positioned under the cutout of the countertop.

VALVE: A device that regulates the flow of water. Also the rough-in part of a faucet that is concealed in the wall or undercounter.