Gas Supply Installation - Desa CERAMIC PLAQUE Service Manual

V E N T - F R E E

Gas Supply Installation

1. Use only new, black iron or steel pipe.
Copper tubing may be acceptable in some
areas but should be internally tinned or
equivalently treated to resist corrosion by
sulphur compounds. CHECK LOCAL
CODES.
2. The gas supply line shall be sized and
installed to provide a sufficient supply of
gas to meet the maximum demand of the
heater without undue loss of pressure.
Model Installed
3-Plaque Models
5-Plaque Models
3. The sealant used on the threaded joints of
the gas pipe must be the specific type
resistant to the action of liquid petroleum
(LP) gas. Apply sealant lightly to the male
threads to ensure excess sealant does not
enter the lines. Any excess sealant could be
forced into the pipe and result in clogged
valves.
IMPORTANT: Pressure regulator
must be held with wrench when
connecting gas piping and/or fittings
to pressure regulator.
External Regulator
(For LP Heaters Only)
G A S H E A T E R
4.
5.
Supply Line
3/8 inch or greater
1/2 inch or greater
The gas supply to the heater must be regulated
to maintain the inlet pressure within the follow-
ing limits:
1/8" NPT Plug Tap
Union
GAS CONNECTION
Drip Leg
(Trap)
Figure 8. Gas Connection
S E R V I C E
The supply system must include a manual
shut-off valve, a union in the line and a
plugged 1/8 inch NPT tap. The tap should
be accessible for test gauge connections
upstream of the gas supply connection to
the heater.
Include a drip leg (trap) in the supply line.
The purpose of the drip leg is to prevent
moisture and contaminants in the gas sup-
ply from entering the heater controls. The
drip leg should be within reach to permit
cleaning or emptying. A drip leg should not
be located where condensation is likely to
freeze. Failure to use a drip leg can result in
operational difficulties with the heater.
Models Gas Pressure
(Inches W.C.)
Natural Gas 7" Min. / 10.5" Max.
Propane 11" Min. / 14" Max.
Manual Shut-off
Valve
GRH/P 001A
M A N U A L
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