Welcome to Keidel's Plumbing Glossary. Every industry and trade has its own standards and terminologies. This glossary is our attempt to help the general public understand some of the terms unique to our industry.

Our database contains over 1000 unique terms, compiled from a variety of public and private sources. To use the glossary efficiently you can click on the letter of the desired term that you would like to find. For example: click on "C" to find out about "Closet Augers" or "P" for "Petcock." Definitions listed here are provided without warranty.

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T

T & C	Threaded and Coupled. Some cast iron pipe is sold threaded with a coupling attached.
T & D	Tested and Drifted. A method of verifying the integrity of used pipe.
T & P Valve	Temperature & pressure relief valve. A safety device used to expel excess pressure or heat from inside a tank.
T & S	Tub and Shower
T-Bolt	The 2 anchor bolts that attach a toilet to the floor. Also known as toilet or closet bolts.
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 Ball	The moving part of the flush valve that seals water in or allows water out of the tank during the flush cycle. Also known as the flapper, flush ball, stopper and seal disk.
Tank Bolts	Three bolts that hold together the tank, gasket and bowl of a 2-piece toilet.
Tank Cross	A double-tee-shaped fitting installed between a shallow well pump and the bladder tank with integrated valve and guage fittings, and an outlet for a pressure-relief valve.
Tank Cover Lock	Device to prevent damage to and removal of the toilet tank cover and contents of the tank.
Tankless Water Heater	Instantaneous water heater
Tannin (Tannic acid)	A substance occurring naturally in well water. It is produced by decaying vegetation, and causes the water to have a yellow of light brown color and can provide a bitter taste. There is currently no EPA regulatory level for tannin in water.
Tap	Faucet. Also refers to the divergence of water from one fitting to another.
Tap Adapter	Fitting with one plain end and one threaded female end
Tap Tee	Cast iron tee with a threaded female side inlet
Tap Water	Water provided by a water company by way of the home's plumbing system.
Tapered Pipe	Standard type of threads used on iron pipe and pipe fittings.
TBE	Threaded Both Ends
TDS	Total dissolved solids
Tee	T-shaped fitting with three openings that allow another pipe to be joined at a 90 degree angle, used to create branch lines.
Teflon Tape	Thread sealing tape with stain resistant, water repellant Teflon finish. Teflon is a trademark of DuPont.
Temperature Rise	The number of degrees Fahrenheit that incoming water must be raised to reach the desired water temperature.
Tempered glass	1. Glass that has been annealed or strengthened by a process of grandually healing and cooling. Once a piece of glass has been tempered, it cannot be cut. If it breaks, it breakes into many small pieces. By code, all shower doors must be made of tempered glass.   2. Water that has been mixed in order to avoid a temperature extreme.
Tempering Valve	A in-line hot/cold mixing valve
Tensile Strength	rating of steel's resistance to being pulled apart
Test Plug	A rubber plug that is used to seal off sections of pipe to allow testing for leakage.
Test Tee	A tee with a removable plug for permitting access to a drainage line
Therm	Measurement of 100,000 BTU's.
Thermal Efficiency	Ability to transfer and absorb heat from fuel sources into the water.
Thermal Expansion	The effect of water expanding when heated.
Thermal Stratification	see stacking
Thermocouple	Small electric generator. Electron flow between the hot junction of 1200 degrees F and cold junction of 600 degrees F creates millivoltage.
Thermopile	Apparatus that consists of a number of thermocouples combined so as to multiply the effect and is used for generating electrical current.
Thermostat (Lower)	Device which automatically maintains a predetermined temperature in an appliance.
Thermostat (Upper)	Device which automatically maintains a predetermined temperature in an appliance, usually equipped with a safety shutoff.
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.
Throatplate	The underside portion of some faucet spouts which also use a top shroud to cover an assembled faucet waterway. The throatplate is only visible when viewed from a very low angle.
Thread Sealant (Liquid)	Provides a water seal in threaded connections.
Thread Sealant (Tape)	Dry ribbons of sealant sold on spools. Unlike liquid sealant there is no chance of it getting into the supply lines and blocking water flow.
Threaded	A helical or spiral ridge on a screw, nut, or bolt.
Through the Floor	Installation where the bath drain tee outlet points down rather than horizontal.
Thumb Nut	To ease installation and to prevent over-tightening this nut was designed to be tightened without tools.
Thumb Screw	To ease installation and to prevent over-tightening this screw was designed to be tightened without tools.
Tile-In	Installation where the sink is fit flush with tile countertop
Tile Rise (Buttress)	The raised portion of a shower curb that is on more than one level.
TO	Threads Only
Toe Tester Spout	A short, stubby wall-mounted tub spout without a diverter.
Toilet	Fixture for disposing of body waste - a bowl-shaped fixture with a waste drain and a flushing device connected to a water supply, used for defecating and urinating
Toilet Setting Compound	Provides a non-hardening watertight seal for the base of the toilet and the floor.
Tool Joint	Threaded tube, usually more thick and hard, welded onto pipe to provide joint strength and durability exceeding that of flush joint or T& C connections.
Total Dissolved Solids	A measure of the total amount of dissolved matter in water
Total Head	The difference between the head at the discharge and suction flange of the pump ( syn Total Dynamic Head, pump head, system head).
Touchless Faucet	Commercially installed faucet or urinal valve that function using infrared sensor system
Total Discharge Head	The total pressure or head the pump must develop. It is the sum of the depth to pumping level, elevation, service pressure, and friction loss.
Toxicity Test	Test to determine the toxicity of a chemical or an effluent using living organisms. It measures the degree of response of an exposed test organism to a specified chemical or effluent
TPI	Threads per inch
Transfer Valve	Valve that changes the flow of water from one outlet to another
Transite Pipe	Pipe manufactured from asbestos and concrete, commonly found in water mains.
Transom Panel	a panel usually located above the door of an enclosure. It can be used to keep steam inside of a steam-shower unit. Some open to vent steam.
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 Drain	A flex adapter to connect 1 ¼" to 1 ½" drain pipe
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	The seal caused by water in a trap preventing septic gasses from leaking back into the home. The trap seal is measured from the inlet of the trapway to the top of the dam. Also referred to as deep seal.
Trapway	Trap built into a toilet connecting the bowl to the waste outlet where siphoning occurs.
Trap Weir	See Crown Weir. An interior projection in the outlet side of a trap to aid in maintaining a water 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.
Trim	Any non-vitreous china toilet components, except the seat. Includes such items as ballcock, bolt caps, trip lever.
Trip Arm	Horizontal bar that connects to the trip lever and trip chain in a toilet. Part of the flush mechanism.
Trip Chain	Chain that connects the toilet trip arm and the flapper on the flush valve
Trip Lever	1. Handle attached to the outside of the toilet tank used to initiate the flush 2. Flush handle and actuating arm on a toilet tank. 3. The lever that opens and closes the drain on the bathtub waste and overflow.
Tube Round	A solid semi-finished round or square bar of steel that is heated and pierced to form a hollow tube for seamless pipe. (see: Billet)
Tubing	A relatively small-diameter pipe used to transport or store liquids.
Tube Talon	Plastic hanger for mounting copper pipe
Tube Valve	A valve which is opened or closed by mechanically moving a tube upstream or downstream by an actuating screw
Tube Washer	Replacement washer for one end of a closet tube
Tuberculation	The process in which blister-like growths of metal oxides develop in pipes as a result of the corrosion of the pipe metal. Iron oxide tubercles often develop over pits in iron or steel pipe, and can seriously restrict the flow of water.
Turbulent Flow	Fluid flow in which the velocity at a given point varies erratically in magnitude and direction.
Turbidity	Water cloudiness caused by suspended particles
Two-Piece Toilet	Toilet with a separate tank and bowl. Also referred to as a close-coupled toilet.
Type "L" Tube	An industry standard for copper tubing defined by the tube wall thickness and identified by a "blue" strip. Type "L" copper tube wall is approximately 50% greater thickness than Type "M."
Type "M" Tube	An industry standard for copper tubing defined by the tube wall thickness and identified by a "red" stripe
Tyseal Gasket	Gasket for joining SV cast iron pipe into a hub

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