41
Nominal
Iron Pipe
Size (Inches)
Natural Gas Pipe Capacity Chart
Length of Pipe in Straight Feet for 1/2 PSI
10
20
30
40
50
60
70
80
90
100
125
150
175
200
1/2
175
120
97
82
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
3/4
369
256
205
174
155
141
128
121
113
106
95
86
79
74
1
697
477
384
328
292
267
246
236
210
200
179
164
149
138
1-1/4
1400
974
789
677
595
543
502
472
441
410
369
333
308
287
1-1/2
2150
1500
1210
1020
923
830
769
707
666
636
564
513
472
441
2
4100
2820
2260
1950
1720
1560
1440
1330
1250
1180
1100
974
871
820
2-1/2
6460
4460
3610
3100
2720
2460
2310
2100
2000
1900
1700
1540
1400
1300
3
11200
7900
6400
5400
4870
4410
4000
3800
3540
3330
3000
2720
2500
2340
4
23500 16100 13100 11100 10000 9000
8300
7690
7380
6870
6150
5640
5130
4720
Shield water heaters are typically shipped ready to fire on natural gas. Check the water heater rating plate to
determine which fuel the water heater is set for. In order to operate on LP gas contact the factory, an orifice
MUST BE installed or a gas valve adjustment MUST BE made. Failure to comply could result in severe
personal injury, death, or substantial property damage.
Table 7A
Natural Gas Pipe Size Chart
The gas piping must be sized for the proper flow and length of
pipe, to avoid excessive pressure drop. Both the gas meter and
the gas regulator must be properly sized for the total gas load.
If you experience a pressure drop greater than 1 inch w.c., the
meter, regulator, or gas line is undersized or in need of service.
Perform the steps below when checking inlet gas supply:
1.
Disconnect power from the appliance.
2.
Shut off gas to the appliance.
3.
Loosen the set screw one (1) full turn from inside the
pressure tap on top of the gas valve. Place the tubing of
the manometer over the tap once the set screw is
loosened as shown in FIG.’s 7-4 thru 7-6.
4.
Slowly turn on the gas supply at the field installed
manual gas valve.
WARNING
5.
Reconnect power to the appliance.
6.
Adjust the temperature set point on the control panel of
the electronic control module to call for heat.
7.
Observe the gas supply pressure as the burner fires at
100% of rated input. Percent of burner input will be
displayed on the control panel.
8.
Ensure inlet pressure is within specified range.
Minimum and maximum gas supply pressures are
specified in this section of the manual.
9.
If gas supply pressure is within normal range and no
adjustments are needed, proceed on to Step 11.
10. If the gas pressure is out of range, contact the gas utility,
gas supplier, qualified installer or service agency to
determine the necessary steps to provide proper gas
pressure to the control.
11. Disconnect power from the appliance.
12. Shut off the gas to the appliance.
13. Remove the manometer from the pressure tap on top of
the gas valve. Re-tighten the set screw inside the pressure
tap.
Check inlet gas supply
NOTICE
CSA or UL listed flexible gas connections
are acceptable, but you must exercise
caution to ensure that the line has
adequate capacity to allow your water
heater to fire at full rate. Consult with
local codes for proper installation or
service procedures.
DO NOT adjust or attempt to measure gas
valve outlet pressure. The gas valve is
factory-set for the correct outlet pressure.
This setting is suitable for natural gas and
propane (when configured for LP),
requiring no field adjustment. Attempting
to alter or measure the gas valve outlet
pressure could result in damage to the
valve, causing potential severe personal
injury, death, or substantial property
damage.
WARNING
7
Gas connections
(continued)
WARNING
When re-tightening the set screw, be sure to
tighten securely to prevent gas leaks.
Do not check for gas leaks with an open
flame -- use the bubble test. Failure to use
the bubble test or check for gas leaks can
cause severe personal injury, death, or
substantial property damage.
14. Reconnect gas to the appliance.
15. Reconnect power to the appliance.
16. Adjust the temperature set point on the control panel of
the electronic control module to the desired
water temperature so the appliance will call for heat.
Installation & Service Manual
TM
