Bosch 330-PN-N Installation Manual page 17

GAS LINE SIZING
The gas supply piping should be sized according to the
applicable code for a maximum draw of 74,900 BTUH.
Measure the length of gas supply line and use the tables in
page 17 or the gas line manufacturer's sizing tables to
determine the pipe diameter necessary to accommodate the
BTU demand of the unit. If there are more gas appliances
FOR NATURAL GAS
Maximum Capacity of pipe in Cubic Feet of Gas per Hour for
Gas Pressure of 0.5 Psig or less and a Pressure drop of 0.3 in
Water Column (0.75mbar).(Based on a 0.60 Specific Gravity
Gas) Btu numbers given in thousands. Copper tubing is
prohibited for use with Natural Gas in the Commonwealth of
Massachusetts and not recommended elsewhere.
Nominal
Iron
Pipe
Internal
Size
Diameter
Inches inches
3/4 0.824
1 1.049
1 - 1/4 1.380
Table 7
Tube
size,
Inches
1/2
3/4
1
1 - 1/4
Table 8
* EHD = Equivalent Hydraulic Diameter. The greater the value
EHD, the greater the gas capacity of the tubing.
FOR LP GAS
Maximum Capatity of Pipe in Thousands of BTU per Hour of
Undiluted Petroleum Gases (at 11 inches Water Column Inlet
330 PN
10 20 30 40
278 190 152 130
520 350 285 245
1050 730 590 500
Lenght of Flexible Corrugated Stainless Steel Tubing (CSST), Feet
EHD* 10
18 82
23 161
30 330
37 639
drawing on the same line, size the gas line according to the total
maximum amount of BTU draw for all appliances.
Note: Under sizing the gas line may result in diminished output
and improper operation. See chapter 4.8 for the procedure to
confirm gas pressure.
Follow boxed numbers for piping just one 330 PN (example: ¾"
B.I. Natural Gas pipe for 20 ft (6.1m). will handle 190,000
btu's (55.7 kWh). For multiple appliances combine the total
btu input load and then refer to applicable chart below.
Lenght of Black Iron Pipe, Feet
50 60 70 80
115 105 96 90
215 195 180 170
440 400 370 350
20 30
58 47
116 96
231 188
456 374
Pressure) (Based on a Pressure Drop of 0.5 Inch Water
Column).
Installation instructions | 17
90 100 125 150
84 79 72 64
160 150 130 120
320 305 275 250
40 50
41 37
83 75
162 144
325 292
6 720 644 951 (2014/11)
175 200
59 55
110 100
225 210
60
34
68
131
267