Part 8 - Gas Connections; Gas Pipe Sizing Tables; Gas Pipe Sizing; Natural Gas Pipe Sizing - Westinghouse Premium WGRT 199 Series Installation, Start-Up, Maintenance, Parts, Warranty

Part 8 - Gas Connections

To avoid serious injury or death, the gas line installation and the gas line inlet pressure test must be done by a licensed professional.
Ensure the gas on which the water heater will operate is the same type specified on the rating plate (natural gas or LP gas). This water
heater must be converted into propane operation unless specifically manufactured for use with propane. Follow Gas Conversion Manual
instructions (separate document). Propane ready water heaters have the suffix "LP" after the model serial number. Failure to follow these
instructions could result in property damage, personal injury, or death.
Make sure the gas line pressures are within normal limits. Pressures outside normal limits can result in poor performance and hazardous
operating conditions. Failure to do so could result in property damage, personal injury, or death.
A. Gas Pipe Sizing Tables

1. Gas Pipe Sizing

This information is for reference use only. Refer to gas pipe manufacturer specifications for actual delivery capacity. The DOE standard for
3
Natural Gas is 1100 BTU/ft . Contact the local gas supplier for actual BTU/ft

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 specific gravity for natural gas.
Pipe Size (in.)
10
3/4 360
1 678
1 1/4
1390
1 1/2
2090
2
4020
3
11300
4 23100
Table 25 - Natural Gas Delivery Capacity - Refer to ANSI Z223.1 - National Fuel Gas Code, Latest Edition

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.
B. Gas Connection Requirements
The gas connection fitting on the water heater is ¾" NPT. NOTE: The pipe size must not be less than ¾".
1.
2. The supply line must be sized for the maximum output of the water heater being installed. If there are additional gas appliances from
the main supply line, measure the size of the supply line according to the COMBINED total maximum BTUH draw for the appliances as
if they were operating at the same time.
3. Measure the length of the gas supply line from the gas meter to the water heater. Water heater must be installed downstream of the
gas meter to ensure adequate gas supply. Use the tables in this manual or refer to the gas line manufacturer's sizing information to
determine the correct supply pipe size.
4. The National Fuel Gas Code (NFPA 54) requires that a sediment trap (drip leg) be installed in the gas line on appliances not so equipped.
The drip leg must be accessible, a minimum of 3" in length, and not subject to freezing conditions. See Figure 43.
5. A manual gas shut-off valve should be installed in the gas
supply line close to the water heater. See Figure 43 for detail.
6. To facilitate any future maintenance, it is also recommended
that an approved gas union fitting be installed in the supply
line between the shut-off valve and the ¾" NPT connection on
the water heater.
7. Use a manometer to test the gas pressure to make sure it
meets the minimum standards and does not exceed the
maximum standards of the water heater.
8. Leak test the gas line pipe before placing the water heater in
operation. Only use approved leak detector liquid solutions
to check for leaks.
9. Do not operate the water heater until all connections have been completed and the heat exchanger is filled with water.
FIRE AND/OR EXPLOSION HAZARD
Length of Pipe (Feet)
20 30 40
247 199 170
466 374 320
957 768 657
1430 1150 985
2760 2220 1900
7780 6250 5350
15900 12700 10900
3
rating.
50 60 80
151 137 117
284 257 220
583 528 452
873 791 677
1680 1520 1300
4740 4290 3670
9660 8760 7490
MANUAL SHUT OFF
BALL VALVE
Figure 43 - Gas Line with Shut-Off and Sediment Trap Detail
100 150 200
Hour x 1,000
104 83 71
Schedule 40
195 157 134
Metallic Pipe
400 322 275
600 482 412
(0.60 Specific
1160 928 794
3260 2610 2240
Pressure Drop)
6640 5330 4560
UNION
SEDIMENT TRAP
whl-004 Rev. 000 Rel. 013 Date 5.1.18
47
BTU's Per
Gravity,
0.5 WC