Gas Piping; Gas Table - Westinghouse WGR-076 Series Installation, Start-Up, Maintenance, Parts, Warranty

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 fire, explosion,
property damage, severe personal injury, or death.
Figure 20 - Gas Connection
A. Gas Piping
Run the gas supply line in accordance with all applicable
codes. Locate and install manual shutoff valves in accordance
with local and state 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, and result in fire, explosion, property damage,
severe personal injury, or death.
Do not use Teflon 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, and result in fire, explosion, property damage,
severe personal injury, or death.
B. Gas Table
Refer to the table below to size the supply piping to minimize
pressure drop between meter or regulator and unit.
Nominal
Internal
Iron Pipe
Dia. (in.)
10
Size (in.)
1/2
3/4 .824 278
1 1.049 520
1 1/4 1.380 1050
Table 10 - Source - ANSI Z223.1
20 30 40 50 60
190 152 130 115 105
650 285 245 215 195
730 590 500 440 400
Maximum capacity of pipe in cubic feet of gas per hour for gas
pressures of .5 psi or less and a pressure drop of .3 inch water
column.
It is recommended that a soapy solution be used to detect leaks.
Bubbles will appear on the pipe to indicate a leak is present.
The gas piping must be sized for 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" WC, the meter,
regulator or gas line is undersized or in need of service. You can
attach a manometer to the incoming gas drip leg by removing
the cap. The gas pressure must remain between 3.5" WC 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 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. Failure to properly purge
the lines or improper line sizing will result in ignition failure.
This problem is especially noticeable in NEW LP installations
and also in empty tank situations. This can also occur when
a utility company shuts off service to an area to provide
maintenance to their lines. 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
flanged connection to the swirl plate and blower.
Length of Pipe (Feet)
70 80 90 100
96 90 84 79
180 170 160 150
370 350 320 305
125 150 175 200
BTU's
Per Hour
72 64 59 55 x 1,000
130 120 110 100
275 250 225 210
WHL-001 Rev. 3.16.15
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