LP-454 Rev. 004 Rel. 002 Date 12.1.17
31
UL recognized fuel gas detectors are recommended in all enclosed
propane and natural gas applications where there is a potential for
an explosive mixture of fuel gas to accumulate. The installation of
these detectors should be made in accordance with the detector
manufacturer’s recommendations, and/or local laws. Failure to
install fuel gas detectors in these applications could result in re,
explosion, property damage, severe personal injury, or death.
Figure 24 - Gas Connection
Table 10 - Source - ANSI Z223.1
Do not remove the adaptor in Figure 24! It is mandatory that this
tting is used for connection to a eld fabricated drip leg per the
National Fuel Gas Code. You must ensure that the entire gas line to
the connection at the appliance is no smaller than 3/4”.
If the water heater experiences a pressure drop greater than 1”
WC, the meter, regulator, or gas line is undersized or in need of
service. A manometer can be attached to the incoming gas drip leg
by removing the cap. The gas pressure must remain between 3.5”
and 14” WC during stand-by (static) mode and while in operating
(dynamic) mode at full output.
If an in-line regulator is used, it must be installed a minimum of 10
feet from the heater. It is very important that the gas line is properly
purged by the gas supplier or utility. Improper line sizing or failure
to properly purge the lines will result in ignition failure. This problem
is especially noticeable in NEW LP installations, in empty tank
situations, or when a utility company shuts o service to an area to
maintain supply lines.
Once all inspections have been performed, the piping must be leak
tested. If the leak test requirement is a higher test pressure than the
maximum gas inlet pressure, isolate the heater from the gas line
to continue leak testing. To do this, turn o the factory and eld-
installed gas cocks. Failure to do so may damage the gas valve.
In the event the gas valve is exposed to a pressure greater than
½ PSI, 14” water column, the gas valve must be replaced. The gas
valve must not be replaced with a conventional gas valve under any
circumstances. As an additional safety feature, the gas valve in this
water heater has a anged connection to the swirl plate and blower.
A. Gas Pipe Sizing Tables
1. Gas Pipe Sizing
This information is for reference use only. Refer to gas pipe
manufacturer specications for actual delivery capacity. The DOE
standard for Natural Gas is 1100 BTU/ft
3
. Contact the local gas
supplier for actual BTU/ft
3
rating.
2. Natural Gas Pipe Sizing
The following table lists maximum capacity of pipe in cubic feet of
gas per hour for gas pressures of 14” or less and a pressure drop of
0.5 inches water column, based on a 0.60 specic gravity for natural
gas.
3. LP (Liquid Propane) Gas Pipe Sizing
Contact gas supplier to size pipes, tanks, and 100% lockup gas
pressure regulator. Adjust propane supply regulator provided
by the gas supplier for 14 inches w.c. maximum pressure.
Pipe Size (in.)
Length of Pipe (Feet)
BTU’s Per
Hour x 1,000
Schedule 40
Metallic Pipe
(0.60 Specic
Gravity,
0.5 WC
Pressure Drop)
10 20 30 40 50 60 80 100 150 200
3/4 360 247 199
1 678 466 374 320 284 257 220
1 1/4 1390 957 768 657 583 528 452 400 322 275
1 1/2 2090 1430 1150 985 873 791 677 600 482 412
2 4020 2760 2220 1900 1680 1520 1300 1160 928 794
3 11300 7780 6250 5350 4740 4290 3670 3260 2610 2240
4 23100 15900 12700 10900 9660 8760 7490 6640 5330 4560
B. Gas Piping Requirements
Support gas supply piping with hangers, not by the heater or its
accessories. The heater gas valve and blower will not support the
weight of the piping. Make sure the gas piping is protected from
physical damage and freezing, where required. Failure to follow
these instructions could result in gas leakage, re, explosion,
property damage, severe personal injury, or death.
Do not use Teon tape on gas line pipe thread. Use a pipe
compound rated for use with natural and propane gases. Apply
sparingly on male pipe ends, leaving the two end threads bare.
Failure to follow these instructions could result in gas leakage, re,
explosion, property damage, severe personal injury, or death.
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