CONQUEST
®
WATER HEATER
17
PV500-71 02/16
6.5 Gas Piping Size
Do not use the gas pipe connection size to determine the gas supply piping. Designing and sizing a gas supply
piping system requires consideration of many factors and must be done by a gas supply piping expert. Always follow
NFPA 54 National Fuel Gas Code for gas pipe sizing and gas pipe system design. The following charts provide
examples of some of the information used by the gas supply piping expert to determine proper pipe sizes.
Use the values in the following table to add the equivalent straight pipe for each elbow or tee to obtain the total
distance from the meter:
Use the following table to determine the possible pipe size based on distance from gas meter for a Single Unit
Installation using Schedule Metallic Gas Pipe.*
SINGLE UNIT INSTALLATION – POSSIBLE SCHEDULE 40 METALLIC GAS PIPE SIZE*
Distance from meter in equivalent feet of schedule 40 metallic gas pipe.* Based on inlet pressure less
than 2 psi, specific gravity of 0.60 and a pressure drop of 0.5 in. w.c.
MODEL
0' - 10'
11' - 25'
26' - 50'
51' - 100'
101' - 200'
201' - 300'
301' - 500'
40
1" 1"
1-1/4"
1-1/4"
1-1/2" 2" 2"
50
1" 1-1/4"
1-1/4"
1-1/2" 2"
2" 2-1/2"
60
1" 1-1/4"
1-1/2"
1-1/2" 2"
2" 2-1/2"
70
1-1/4" 1-1/4" 1-1/2" 2"
2"
2-1/2" 2-1/2"
80
1-1/4"
1-1/4"
1-1/2" 2" 2-1/2"
2-1/2" 3"
*See NFPA 54 National Fuel Gas Code for actual pipe size selection and for sizing Propane gas piping
*See NFPA 54 National Fuel Gas Code for actual pipe size selection and for sizing Propane gas piping
6.6 Appliance Isolation during Gas Supply Piping Pressure Test
1. The appliance and its provided manual shutoff valve must be disconnected from the gas supply piping system
during any pressure testing of that system at test pressures in excess of ½ PSI (3.5 kPa).
2. The appliance must be isolated from the gas supply piping system by closing its individual manual shutoff valve
during any pressure testing of the gas supply piping system at test pressures equal to or less than ½ PSI (3.5
kPa).
3. The appliance and its gas connection must be leak-tested before placing it in operation.
CONVERT FITTINGS TO EQUIVALENT STRAIGHT PIPE*
Diameter Fitting (inches)
¾" 1" 1¼" 1½"
2"
3" 4" 5"
Equivalent Length of Straight Pipe (feet)
2' 2'
3'
4'
5'
10' 14' 20'
MULTIPLE UNIT INSTALLATIONS SCHEDULE 40 METALLIC GAS PIPE SIZE CHART*
Maximum Capacity of Pipe in Thousands of BTU’s per hour for gas pressures of 14 Inches Water Column (0.5
PSIG) or
less and a pressure drop of 0.05 Inch Water Column (Based on NAT GAS, 1025BTU’s per Cubic Foot of Gas and
0.60 Specific Gravity).*
Nominal Iron
Pipe Size,
Inches
Length of Pipe in Straight Feet
10 20 30 40 50 60 70 80 90 100 125 150 175 200
3/4
369 256 205 174 155 141 128 121 113 106 95 86 79 74
1
697 477 384 328 292 267 246 256 210 200 179 164 49 138
1 1/4
1400 974 789 677 595 543 502 472 441 410 369 333 308 287
1 1/2
2150
1500
1210
1020 923 830 769 707 666 636 564 513 472 441
2
4100 2820 2260 1950 1720 1560 1440 1330 1250 1180 1100 974 871 820
2 1/2
6460 4460 3610 3100 2720 2460 2310 2100 2000 1900 1700 1540 1400 1300
3
11200 7900 6400 5400 4870 4410 4000 3800 3540 3300 3000 2720 2500 2340
4
23500
16100 13100 11100 10000 9000 8300 7690 7380 6870 6150 5640 5130 4720
