Bosch Model GWH 425 - Manual (Page 12)

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12
Installation instructions
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.
Fig. 14
Follow boxed numbers for piping just one GWH 425 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.
* EHD = Equivalent Hydraulic Diameter. The greater the
value of EHD, the greater the gas capacity of the tubing
.
Maximum Capacity of Semi-Rigid copper Tubing in
Thousands of BTU per Hour of Undiluted Liquefied
Petroleum Gases (at 11 inches Water Column Inlet
Pressure).
(Based on a Pressure Drop of 0.5 Inch Water Column)
* Source National Fuel Gas Code NFPA 54, ANSI Z223.1
- No Additional Allowance is necessary for an ordinary
number of fittings
FOR LP GAS
Maximum Capacity of Pipe in Thousands of BTU per Hour of Undiluted Petroleum Gases (at 11 inches Water Column Inlet
Pressure) (Based on a Pressure Drop of 0.5 Inch Water Column).
* EHD = Equivalent Hydraulic Diameter. The greater the
value of EHD, the greater the gas capacity of the tubing.
Tube
size,
inches
EHD*
10 20 30 40 50 60
1/2 18 EHD 82 58 47 41 37 34
3/4 23 EHD 161 116 96 83 75 68
1 30 EHD 330 231 188 162 144 131
1 1/4 37 EHD 639 456 374 325 292 267
Length of Flexible Corrugated Stainless Steel Tubing (CSST), Feet
Tube
size
inches
EHD*
10 20 30 40 50 60
1/2 18 EHD 129 91 74 64 58 53
3/4 23 EHD 254 183 151 131 118 107
1 30 EHD 521 365 297 256 227 207
1 1/4 37 EHD 971 661 528 449 397 359
Length of Flexible Corrugated Stainless Steel Tubing (CSST), Feet
Nominal
Iron
Pipe
Internal
Size Diameter
inches inches 10 20 30 40 50 60 70 80 90 100 125 150 175 200
3/4 0.824 278 190 152 130 115 105 96 90 84 79 72 64 59 55
1 1.049 520 350 285 245 215 195 180 170 160 150 130 120 110 100
1 1/4 1.380 1050 730 590 500 440 400 370 350 320 305 275 250 225 210
Length of Black Iron Pipe, Feet
N o minal
Iro n pipe
size
inches
10 20 30 40 50 60 80 100 125 150 200
1/2 291 200 160 137 122 110 94 84 74 67 58
3/4 608 418 336 287 255 231 197 175 155 140 120
1 1145 787 632 541 480 434 372 330 292 265 227
Black Iron Pipe
Lenght of pipe, Feet
Copper (LP gas only)
Outside Length of Tubing, Feet
diameter
Inch
10 20 30 40 50 60 70 80 90 100
3/8 39 26 21 19 _ _ _ _ _ _
1/2 92 62 50 41 37 35 31 29 27 26
5/8 199 131 107 90 79 72 67 62 59 55
3/4 329 216 181 145 131 121 112 104 95 90