Rheem 136-1826 User Manual
Page 18
PIPING: General. Consult particular heater section for specific information.
a. GAS
Gas piping must be installed in accordance with the latest edition of the National Fuel Gas Code ANSI
Z 223.1 and other local or regulatory agency codes that have jurisdiction.
1. Check heater rating plate for
•
Correct Fuel Gas
•
Rated input to meet local conditions such as altitude, gas specification, etc.
2. Piping from meter must be of sufficient size to provide the required amount of gas at flowing
pressures as follows:
Gas
Natural
Propane
BTU/CF
1000
2500
SP. GR
0.60
1.53
Minimum Flowing Pressure
7" W.C.
12" W.C.
Maximum Shut-off Pressure
14" W.C.
14" W.C.
PIPE SIZES
Fuel
Nat.
Propane
Length(feet)
0-100
100-200
200-300
0-100
100-200
200-300
Model
136
3/4
1
1-1/4
3/4
1
1
181
1
1-1/4
1-1/4
1
1
1-1/4
264
1-1/4
1-1/4
1-1/2
1
1-1/4
1-1/4
331
1-1/4
1-1/2
1-1/2
1-1/4
1-1/4
1/1/2
399
1-1/4
1-1/2
1-1/2
1-1/4
1-1/4
1-1/2
512
1-1/2
2
2
1-1/4
1-1/2
1-1/2
627
1-1/2
2
2
1-1/2
1-1/2
2
726
2
2
2
1-1/2
2
2
825
2
2
2-1/2
2
2
2
926
2
2-1/2
2-1/2
2
2
2
962
2
2-1//2
2-1/2
2
2
2
1083
2
2-1/2
2-1/2
2
2
2
1125
2
2-1/2
2-1/2
2
2
2
1178
2-1/2
2-1/2
3
2
2
2-1/2
1223
2-1/2
2-1/2
3
2
2
2-1/2
1287
2-1/2
3
3
2
2-1/2
2-1/2
1337
2-1/2
3
3
2
2-1/2
2-1/2
1413
2-1/2
3
3
2
2-1/2
2-1/2
1467
2-1/2
3
3
2
2-1/2
2-1/2
1570
2-1/2
3
3
2
2-1/2
3
1630
2-1/2
3
3
2
2-1/2
3
1758
2-1/2
3
3
2
2-1/2
3
1826
2-1/2
3
3
2
2-1/2
3
Chart is based on:
0.5" W.C. Pressure Drop Natural Gas
0.6" W.C. Pressure Drop Propane Gas
Fitting provided in gas line have equivalent length of pipe, in feet, as follows:
Size
3/4
1
1-1/4
1-1/2
2
2-1/2
3
4
Elbow
2.5
3
4
4.5
5.5
6.5
8
12
Tee
5
6
8
9
12
14
17
22
3. All gas piping must be tested after installation with air or an inert gas and all connections should be
checked using a soapy solution.
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