Use And Care Manual

whl-004 Rev. 000 Rel. 012 Date 3.22.18
47
Part 8 - Gas Connections
FIRE AND/OR EXPLOSION HAZARD
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 specied on the rating plate (natural gas or LP gas). This water
heater must be converted into propane operation unless specically manufactured for use with propane. Follow Gas Conversion Manual
instructions (separate document). Propane ready water heaters have the sux “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 specications 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 specic gravity for natural gas.
Pipe Size (in.)
Length of Pipe (Feet)
BTU’s Per
Hour x 1,000
Schedule 40
Metallic Pipe
(0.60 Specic
Gravity,
0.5 WC
Pressure Drop)
10 20 30 40 50 60 80 100 150 200
3/4 360 247 199 170 151 137 117 104 83 71
1 678 466 374 320 284 257 220 195 157 134
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
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
1. The gas connection tting on the water heater is ¾” NPT. NOTE: The pipe size must not be less than ¾”.
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.
UNION
SEDIMENT TRAP
MANUAL SHUT OFF
BALL VALVE
Figure 43 - Gas Line with Shut-O and Sediment Trap Detail
5. A manual gas shut-o 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 tting be installed in the supply
line between the shut-o 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 lled with water.