GLOSSARY OF PLUMBING TERMS | V

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

V-Clip – A clip shaped like the letter “V” used on a lavatory drain lift linkage assembly to easily adjust connection of the drain to the lift rod.

Vacuum Breaker – An anti-siphon device that prevents the backflow of contaminated water into the water supply system.

Valve – A device that regulates the flow of water.

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.

Valve Seat Wrench – Hexagonal end wrench inserted into the hexagonal opening in a valve seat for installing or removal.

Vanity – A bathroom storage cabinet under the wash basin.

Velocity Head – The amount of energy required to accelerate water to a given velocity; expressed in feet per head.

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.

Venting Materials – Materials used for venting, i. e. PVC, CPVC, ABS, metal.

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 Surface – Surface material on some plumbing fixtures derived from or consisting of glass, translucent, and low on porosity.

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.

Volatile – Capable of vaporization at a relatively low temperature.

Volt – Unit of measure of electromotive force.

Volumetric – Referring to measurement by volume rather than weight.

Volute Casing – Derives is name from a spiral shaped casing surrounding the pump impeller. It converts velocity energy to pressure energy.

Voral Tube – Flexible steel hose used for hand-held shower sprays.

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Source: “Plumbing Terms” Standard Plumbing Supply. 11 Sept. 2008