Gas Piping; Gas Table - Westinghouse WGR050NG076 Installation Instructions Manual

The gas supply shall have a maximum inlet pressure of less than 14" water
column (350 mm), ½ pound pressure (3.5 kPa), and a minimum of 3.5" water
column. The entire piping system, gas meter and regulator must be sized
properly to prevent pressure drop greater than 0.5" WC as stated in the
National Fuel Gas Code. This information is listed on the rating plate.
It is very important that you are connected to the type of gas as noted on the
rating plate: "LP" for liquefied petroleum, propane gas, or "Nat" for natural or
city gas. All gas connections must be approved by the local gas supplier or
utility, in addition to the governing authority, prior to turning the gas supply
on.
Do not remove the adaptor in
for connection to a field fabricated drip leg per the National Fuel Gas Code.
You must ensure that the entire gas line to the connection at the water heater
is no smaller than ½".
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, you must isolate the heater from the gas line to continue leak
testing. To do this, you must turn off the factory and field-installed gas cocks.
This will minimize the possibility of damaging the gas valve. 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. Never use an open flame (match, lighter, etc.) to
check gas connections.
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.
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.
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.
Nominal Iron Internal
Pipe Size (In.) Dia. (In.)
½
¾ .824
1 1.049
1 ¼ 1.380
Table 9 – Source – ANSI Z223.1
! It is mandatory that this fitting is used
Figure 20
10 20 30 40
278 190 152 130
520 350 285 245
1,050 730 590 500
Figure 20 –Gas Connection
Length of Pipe (Feet)
50 60 70 80
115 105 96 90
215 195 180 170
440 400 370 350
90 100 125 150
84 79 72 64
160 150 130 120
320 305 275 250
39
BTU's
175 200
Per Hour
59 55
x
110 100 1,000
225 210
WHL-001 REV. 9.3.14