Installation Guide
45
PSI
Pounds per square inch gauge. The pressure, as read from a measurement gage or
device. Gauge pressure is pressure above atmospheric pressure.
Purge
To displace the original air, or gas, or a mixture of gas and air in a gas conduit with a
new air/gas mixture.
Regulator
A device that reduces and controls pressure. It automatically opens and closes in
response to changing pressure conditions in the downstream piping.
Regulator, Appliance
A device for controlling and maintaining a uniform pressure to the
manifold of gas burning equipment. This valve is typically part of the appliance. It reduces the
pressure from 5.5" w.c. to the manifold pressure in the appliance.
Regulator, Line Gas Pressure (PSI to inches w.c.)
A device placed in a gas line between the
service regulator and the appliance regulator for controlling, maintaining or reducing the
pressure in that portion of the piping system downstream of the device. This valve reduces
the house line pressure (typically 2 PSI) to the regulator manifold pressure (typically 8-10"
w.c.).
Regulator, Service (PSI or inches w.c.)
A device installed by the serving gas supplier to
reduce and limit the service line gas pressure. This valve reduces the service pressure to the
metering pressure. It is located upstream of the gas meter.
Regulator Vent
The opening in the atmospheric side of the regulator housing permitting
the in and out movement of air to compensate for the movement of the regulator diaphragm.
Specic Gravity
As applied to gas, the ratio of the weight of a given volume to that of the
same volume of air, both measured under the same conditions.
Valve, Manual Shut-o
A valve (located in the piping system and readily accessible and
operable by the consumer) used to shut o individual equipment.
Vent Limiter Device
Restriction/orice type device in the vent outlet of a pressure regulator
that controls or limits leakage, in the event of a diaphragm leak. It also allows the diaphragm
to move freely to control pressure.