Gas piping, 2 — boiler manual – Ultra electronic -155 User Manual
Page 22
Part number 550-100-026/0404
GAS
-
FIRED
WATER
BOILER
SERIES
2 — Boiler Manual
22
Table 4
Pipe capacity for 0.60 specific gravity natural gas
Gas piping
(continued)
5
Natural Gas:
Pipe sizing for natural gas
1. Refer to Table 4 for pipe length and diameter. Base on
rated boiler input (divide by 1,000 to obtain cubic
feet per hour).
a. Table 4 is only for natural gas with specific gravity 0.60,
with a pressure drop through the gas piping of 0.30"
w.c.
b. For additional gas pipe sizing information, refer to
ANSI Z223.1 (or B149.1 or B149.2 for Canadian
installations).
Natural gas supply pressure requirements
1. Pressure required at gas valve inlet pressure port:
• Maximum: 13" w.c. with no flow (lockup) or with
boiler on
• Minimum: 5" w.c. with gas flowing (verify during boiler
startup, while boiler is at high fire)
2. Install 100% lockup gas pressure regulator in supply
line if inlet pressure can exceed 13" w.c. at any time.
Adjust lockup regulator for 13" w.c. maximum.
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
Propane Gas:
Ultra boilers are shipped ready to fire
natural gas ONLY (exception: Ultra-80-LP
is propane-ready). You must install the
propane orifice if the boiler will be
connected to propane. See page 9. Failure
to comply could result in severe personal
injury, death or substantial property
damage.
Pipe sizing for natural gas
1. Contact gas supplier to size pipes, tanks and 100%
lockup gas pressure regulator.
Propane supply pressure requirements
1. Adjust propane supply regulator provided by gas
supplier for 13" w.c. maximum pressure.
2. Pressure required at gas valve inlet pressure port:
• Maximum: 13" w.c. with no flow (lockup) or with
boiler on
• Minimum: 4" w.c. with gas flowing (verify during boiler
startup, while boiler is at high fire)