Temperature & pressure relief valve. A safety device used to expel excess pressure or heat from inside a 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.

A T-shaped fitting with three openings used to create branch lines.

Small electric generator. Electron flow between the hot junction of 1200 degrees F and cold junction of 600 degrees F creates millivoltage.

A device used for regulating the temperature of a heating system.

An individual thermostat fitted to a radiator to regulate the temperature of the room in which it is installed.

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.

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.

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.