CGi Manual

Part Number 550-142-302/0520
CGi
SERIES 4 — GAS-FIRED WATER BOILER — Boiler Manual
30
Gas piping5
Table 7 Pipe capacity for 0.60 specific gravity natural gas
Natural Gas:
1. Refer to Table 7 for pipe length and diameter. Base on rated
boiler input (divide by 1,000 to obtain cubic feet per hour).
Table 7 is only for gas with specific gravity 0.60, with a
pressure drop through the gas piping of 0.30” w.c.
For
additional gas pipe sizing information, refer to ANSI Z223.1/
NFPA 54 – latest edition (or B149.1 or B149.2 for Canadian
Natural Gas and Propane Installation Code).
2. Inlet pressure required at gas valve inlet:
• Maximum: 13” w.c.
• Minimum: 5” w.c.
• Manifold gas pressure: 3.5” w.c.
3. Install 100% lockup gas pressure regulator in supply line
if
inlet pressure exceeds 13” w.c.
Adjust for 13” w.c. maxi-
mum.
Propane Gas:
1. Contact gas supplier to size pipes, tanks and 100% lockup
gas pressure regulator.
2. Adjust propane supply regulator provided by gas supplier for
13” w.c. maximum pressure.
3. Inlet pressure required at gas valve inlet:
• Maximum: 13” w.c.
• Minimum: 11” w.c.
• Manifold gas pressure: 10” w.c.
Connecting gas supply piping to
boiler
1. Remove jacket front panel and refer to Figure 26 to pipe gas
to boiler.
a.
Install drip leg at inlet of gas connection to boiler.
Where local utility requires drip leg to be extended to
the floor, use appropriate length of pipe between cap
and tee.
b.
Install ground joint union for servicing, when re-
quired.
c.
Install manual shutoff valve in gas supply piping out-
side boiler jacket when required by local codes or utility
requirements.
d.
In Canada — When using manual main shutoff valve, it
must be identified by the installer.
2.
Support piping with hangers, not by boiler or its accessories.
3. Purge all air from gas supply piping.
4. Before placing boiler in operation,
check boiler and its gas
connection for leaks
.
a.
Close manual main shutoff valve during any pressure
testing at less than 13” w.c.
b.
Disconnect boiler and gas valve from gas supply
piping
during any pressure testing greater than 13” w.c.
Do not check for gas leaks with an open
flame
— use bubble test. Failure to use bubble
test or check for gas leaks can cause severe
personal injury, death or substantial property
damage.
5.
Use pipe dope compatible with propane gases. Apply
sparingly only to male threads of pipe joints so that pipe dope
does not block gas flow.
Failure to apply pipe dope as detailed above
can result in severe personal injury, death or
substantial property damage.
Figure 26 Gas supply piping
Gas pipe
length
(feet)
Capacity of pipe for pipe size of:
(Capacity in cubic feet gas per hour)
½” ¾” 1” 1¼” 1½”
10 132 278 520 1050 1600
20 92 190 350 730 1100
30 73 152 285 590 860
40 63 130 245 500 760
50 56 115 215 440 670
75 45 93 175 360 545
100 38 79 150 305 460
150 31 64 120 250 380