Freestyle 2 Series - Gas Piping - Sizing Gas Lines

Part number 550-142-950/0122
14
FreeStyle
®
series 2 wall mount gas-fired water boiler – boiler manual
5 Gas piping — sizing gas lines
Boiler gas connection is ½” NPT for 80/120 boilers
and ¾” NPT for 155 boilers. Size gas lines large
enough to provide gas to all connected appliances.
Natural Gas:
Pipe sizing for natural gas
1. Size gas piping from meter outlet to entrance of boiler in
accordance with Figure18 and Figure19.
2. Use total input of all connected appliances. Divide total input
in Btuh by 1,000 to obtain cubic feet per hour of natural gas.
a. Pipe lengths in Figure18 are equivalent length of straight
pipe. Convert pipe ttings to equivalent lengths using
data from Figure19.
b. Figure18 is only for natural gas with specic gravity 0.60,
with a pressure drop through the gas piping as listed in
the table.
Natural gas supply pressure
1. Pressure required at gas valve inlet pressure port:
a. Maximum: 13” (330 mm) w.c. with no ow (lockup).
b. Minimum gas pressure, with gas owing (verify during
boiler startup, while boiler is at high re):
FreeStyle
®
80: 3.5” w.c.
FreeStyle
®
120: 3.5” w.c.
FreeStyle
®
155: 3.5” w.c.
Nominal gas pressure: 7.0” w.c.
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.
Propane Gas:
You must follow the instructions, beginning on
page10, to operate the boiler on propane. Failure
to comply could result in severe personal injury,
death or substantial property damage.
Pipe sizing for propane gas
1. Contact gas supplier to size pipes, tanks and 100% lockup
gas pressure regulator.
Propane supply pressure
1. Adjust propane supply regulator provided by gas supplier for
13” w.c. maximum pressure.
2. Pressure required at gas valve inlet pressure port:
a. Maximum: 13” w.c. with no ow (lockup).
b. Minimum gas pressure, with gas owing (verify during
boiler startup, while boiler is at high re):
FreeStyle
®
80: 3.5” w.c.
FreeStyle
®
120: 3.5” w.c.
FreeStyle
®
155: 3.5” w.c.
Nominal gas pressure: 11.0” w.c.
Figure 18 Pipe capacity for 0.60 specic gravity natural
gas; pipe length is in equivalent feet
Gas
pipe
total
length,
feet
Capacity
Cubic feet per hour, natural gas, 0.60 specic gravity
Gas pressure 13” w.c. or less
Pressure drop 0.3 inches w.c.
½” ¾” 1” 1¼” 1½” 2” 2½”
10
132 278 520 1050 1600 3050 4800
20
92 190 350 730 1100 2100 3300
30
73 152 285 590 890 1650 2700
40
NA 130 245 500 760 1450 2300
50
NA 115 215 440 670 1270 2000
75
NA 105 175 360 545 1020 1650
100
NA 96 150 305 460 870 1400
150
NA 90 120 250 380 710 1130
Figure 19 Equivalent lengths of straight pipe for typical
gas line ttings
Pipe size
(inches)
Equivalent length, feet
90° Elbow Tee
short
radius
long
radius
line
ow
branch
ow
½ 3.6 2.2 1.7 4.2
¾ 4.4 2.3 2.4 5.3
1 5.2 2.7 3.2 6.6
1¼ 6.6 3.2 4.6 8.7
1½ 7.4 3.4 5.6 9.9
2 8.5 3.6 7.7 12.0
2½ 9.3 4.0 9.3 13.0