Natural Gas; Pipe Sizing For Natural Gas; Natural Gas Supply Pressure Requirements; Propane Gas - Cadet 40-120 Installation And Service Manual

7
Gas connections
Failure to apply pipe sealing compound
WARNING
as detailed in this manual can result
in severe personal injury, death, or
substantial property damage.
Cadet heating boilers are typically
WARNING
shipped ready to fire on natural gas.
Check boiler rating plate to determine
which fuel the boiler is set for. If set to
natural gas, it may be converted to LP
by installing an orifice (see page 12).
In order to operate on LP gas, an orifice
MUST BE installed. Failure to comply
could result in severe personal injury,
death, or substantial property damage.
Use two wrenches when tightening gas
WARNING
piping at boiler (FIG. 7-2), using one
wrench to prevent the boiler gas line
connection from turning.
support the boiler gas connection pipe
to prevent it from turning could damage
gas line components.
Figure 7-2 Inlet Pipe with Backup Wrench
Maximum inlet gas pressure must not
NOTICE
exceed the value specified. Minimum
value listed is for the purposes of input
adjustment.
(continued)

Natural gas:

Pipe sizing for natural gas

1. Refer to Table 7A for pipe length and diameter. Based on
rated boiler input (divide by 1,000 to obtain cubic feet per
hour).
a.
b.

Natural gas supply pressure requirements

1. Pressure required at the gas valve inlet pressure port:
• Maximum 14 inches w.c. with no flow (lockup) or with
• Minimum 4 inches w.c. with gas flowing (verify during
Failure to
2. Install 100% lockup gas pressure regulator in supply line if
inlet pressure can exceed 14 inches w.c. at any time. Adjust
lockup regulator for 14 inches w.c. maximum.

Propane Gas:

WARNING Cadet heating boilers are typically shipped

Pipe sizing for propane gas

1. Contact gas supplier to size pipes, tanks, and 100%
USE BACK UP WRENCH
TO PREVENT PIPE FROM
ROTATING

Propane Supply Pressure Requirements

IMG00243
1. Adjust propane supply regulator provided by the gas
2. Pressure required at gas valve inlet pressure port:
WARNING
Installation & Service Manual
Table 7A is only for natural gas with specific gravity
0.60 inches, with a pressure drop through the gas
piping of 0.5 inches w.c.
For additional gas pipe sizing information, refer to
ANSI Z223.1 (or B149.1 for Canadian installations).
boiler on.
boiler startup).
ready to fire on natural gas. Check boiler
rating plate to determine which fuel the
boiler is set for. If set to natural gas, it may be
converted to LP by installing an orifice (see
page 12). In order to operate on LP gas, an
orifice MUST BE installed. Failure to comply
could result in severe personal injury, death,
or substantial property damage.
lockup gas pressure regulator.
supplier for 14 inches w.c. maximum pressure.
• Maximum 14 inches w.c. with no flow (lockup) or with
boiler on.
• Minimum 8 inches w.c. with gas flowing (verify during
boiler startup).
Ensure that the high gas pressure regulator
is at least 6 - 10 feet upstream of the
appliance.
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