John Wood Commercial - AJWS User Manual
Page 14
14
L.P. Gas Capacity
Size, (in)
10
20
30
40
50
60
70
80
90
100
125
150
1/2
275
189
152
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
3/4
576
393
315
267
237
217
196
185
173
162
146
132
1
1071
732
590
504
448
409
378
346
322
307
275
252
1-1/4
2205
1496
1212
1039
913
834
771
724
677
630
567
511
Maximum capacity of gas pipe in thousands of BTU per hour of undiluted liquified petroleum gasses (at 11 inches
water column pressure). Based on a Pressure Drop of 0.5 Inch Water Column.
Nominal Iron Pipe
Length of pipe, Feet
Example: Input BTU requirements of the water heater, 199,000 BTUH
Total pipe length, 80 feet - 1" IPS required.
L.P. Gas Capacity
Size, (in)
10
20
30
40
50
60
80
100
125
5/8
206
141
n/a
n/a
n/a
n/a
n/a
n/a
n/a
3/4
348
239
192
164
146
132
n/a
n/a
n/a
7/8
536
368
296
253
224
203
174
154
137
Maximum capacity of gas pipe in thousands of BTU per hour of undiluted liquified petroleum gasses (at 11 inches
water column pressure). Based on a Pressure Drop of 0.5 Inch Water Column.
Copper Tubing OD
Example: Input BTU requirements of the water heater, 199,000 BTUH
Total pipe length, 50 feet = 7/8" IPS required.
Length of pipe, Feet
Natural Gas Pipe Capacity (Cu. ft./hr)
Size, in.
10
20
30
40
50
60
70
80
90
100
125
150
175
200
1/2
132
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
3/4
278
190
152
130
115
105
96
n/a
n/a
n/a
n/a
n/a
n/a
n/a
1
520
350
285
245
215
195
180
170
160
150
130
120
110
100
1-1/4 1050
730
590
500
440
400
370
350
320
305
275
250
225
210
1-1/2 1600 1100
890
760
670
610
560
530
490
460
410
380
350
320
Cu. Ft. Per Hr. Required =
Gas Input of Water Heater (BTU/HR)
Heating Value of Gas (BTU/FT
3
)
The gas input of the water heater is marked on the water heater data plate. The heating value of the gas (BTU/ft
3
) may
be determined by consulting the local natural gas utility.
Capacity of gas pipe of different diameters and lengths in cu. ft. per hr. with pressure drop of 0.3 in. and specific
gravity of 0.60 (natural gas).
Nominal Iron Pipe
Length of Pipe, Feet
After the length of pipe has been determined, select the pipe size which will provide the maximum cubic feet per hour
required for the gas input rating of the water heater. By formula:
Table 2
Table 3 - A
Table 3 - B