Natural Gas Pipe Sizing; Natural Gas Supply Pressure Requirements; Propane Gas Pipe Sizing; Propane Gas Supply Pressure Requirements - Watts Aerco AM Series Operation & Maintenance Manual

AM Series Pool Heater User Manual
SECTION 6: INSTALLATION - NATURAL GAS
The unit is shipped ready to fire on natural gas. Check appliance rating plate to determine which
fuel the appliance is set for. If set to natural gas, it may be converted to propane gas following
instructions in Section 7.9 of AM Series User Manual GF-146.

6.4 Natural Gas Pipe Sizing

Refer to the table below for pipe lengths and diameters. For additional gas pipe sizing information,
refer to ANSI Z223.1 (or B149.1 for Canadian installations).
TABLE 7-1: Gas Pipe Capacity for Natural Gas
Nominal: 3/4
Actual ID: 0.824
)
Length (ft
10 273
20 188
30 151
40 N/A
50 N/A
60 N/A
70 N/A
80 N/A
90 N/A
100 N/A
125 N/A
150 N/A
175 N/A
200 N/A
250 N/A
NOTE:
Maximum pipe capacity is based on a 0.60 specific gravity gas at a pressure of 0.5 PSIG and
a 0.3" W.C. pressure drop.

6.5 Natural Gas Supply Pressure Requirements

•
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.
•
Pressure required at the gas valve inlet pressure port:
o Maximum 13" W.C. with no flow (lockup) or with appliance off.
o Minimum 3" W.C. with gas flowing (verify during high fire).

6.6 Propane Gas Pipe Sizing

Contact gas supplier to size pipes, tanks, and 100% lockup propane gas pressure regulator.

6.7 Propane Gas Supply Pressure Requirements

•
Adjust propane supply regulator provided by the gas supplier for 13"W.C. maximum pressure.
•
Pressure required at the gas valve inlet pressure port:
o Maximum 13" W.C. with no flow (lockup) or with appliance off.
OMM-0111_B: • GF-146-P • 10/29/2019
Iron Pipe Size (in)
1 1 1/4 1 1/2
1.049 1.380 1.610
Capacity in Cubic Feet of Gas per Hour
514 1060 1580
353 726 1090
284 583 873
243 499 747
215 442 662
195 400 600
179 368 552
167 343 514
157 322 482
148 304 455
131 269 403
119 244 366
N/A 224 336
N/A 209 313
N/A 185 277
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
2 2 1/2 3
2.067 2.469 3.068
3050 4860 8580
2090 3340 5900
1680 2680 4740
1440 2290 4050
1280 2030 3590
1160 1840 3260
1060 1690 3000
989 1580 2790
928 1480 2610
877 1400 2470
777 1240 2190
704 1120 1980
648 1030 1820
602 960 1700
534 851 1500
4
4.026
17500
12000
9660
8270
7330
6640
6110
5680
5330
5040
4460
4050
3720
3460
3070
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