Plumbing Glossary

ACRYLIC: 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

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

BASKET STRAINER: 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.

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

CENTERSET: 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.

COMPRESSION FITTING: 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.

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

DIVERTER: 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.

I.D. (Inner 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.

ROUGH-IN: 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.

TRIM KIT: 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 under counter.