Questar Gas - Good Practices for Gas Piping and Appliance ...

spaces below raised floors of computer/data processing centers,
or attic spaces, to which one or more ducts are connected and
which forms part of either the supply-air, return-air or exhaust-air
system other than the occupied space being conditioned.
POWER EXHAUSTER - A device installed in and made a part of
the vent which will provide a positive induced draft.
PRESSURE DROP - The loss in pressure due to friction, valves,
fittings or regulators.
PRESSURE RELIEF DEVICE - A pressure-actuated valve or rupture
member designed to automatically relieve excessive pressure.
PURGE - To free a gas conduit of air, gas or a mixture of gas and air.
QUICK DISCONNECT DEVICE - A hand-operated device which
provides a means for connecting and disconnecting an appliance
or an appliance connector to a gas supply which is equipped with
an automatic means to shut off the gas supply when the device is
disconnected.
REGULATOR - A device for controlling and maintaining a uniform
gas supply pressure.
RELIEF OPENING - The opening provided in a draft hood to
permit the ready escape to the atmosphere of the flue products
from the draft hood in the event of no draft, back draft, or stoppage
beyond the draft hood, and to permit dilution air into the draft
hood in the event of a strong chimney updraft.
ROOM HEATER - A self-contained, vented, gas-burning, airheating
appliance intended for installation in the space being heated
and not intended for duct connection. This definition shall not
include unit heaters, central heating gas appliances or garage
heaters.
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