Plumbing Dictionary


Plumbing termonalogy.

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U

UNCONFINED SPACE

A space whose volume is not less than 50 cu ft per 1,000 Btu/hour (4.83 m3/kW) of the aggregate input rating of all appliances installed in that space. Rooms communicating directly with the space in which the appliances are installed, through openings not furnished with doors, are considered a part of the unconfined space.

UNIT HEATER

A self-contained gas-burning appliance of the fan type, designed for the delivery of warm air directly into the space in which the appliance is located.

UNLISTED BOILER

A boiler not listed by a nationally recognized testing agency or a boiler not originally furnished by the manufacturer with integrally assembled gas burner and automatic control devices.

UNMEASURED GAS

Gas which has not passed through and the volume of which has not been registered by a meter, or gas which has not otherwise been measured, such as by liquid volume or weight.

UNSTABLE GROUND

Earth that does not provide a uniform bearing for the barrel of the sewer pipe between the joints at the bottom of the pipe trench.

UNUSUALLY TIGHT CONSTRUCTION

Construction meeting the following requirements: Walls and ceilings exposed to the outside atmosphere have a continuous water vapor retarder with a rating of one perm (57.4 ng/s .m2 .Pa) or less with openings gasketed or sealed, and Storm windows or weather-stripping on open able windows and doors, and Caulking or sealants applied to areas such as joints around window and door frames, between sole plates and floors, between wall-ceiling joints, between wall panels, at penetrations for plumbing, electrical, and gas lines, and at other openings.

UNVENTED ROOM HEATER

An unvented self-contained, free standing, nonrecessed (except as defined under ALL WEATHER, UNVENTED CLOSED FRONT), gas-burning appliance for furnishing warm air by gravity or fan circulation to the space in which installed directly from the heater without duct connection.

URINAL

Water-flushed plumbing fixture designed to receive only liquid waste which is conveyed through a trap seal into a gravity drainage system.