21
GAS SUPPLY AND PIPING:
To properly size the gas piping for the heater, refer to Tables 10, 11, 12, and 13, depending on natural
or propane gas, and single-stage or 2-stage regulation. Follow local gas codes for proper gas line material
selection (copper, iron, plastic, etc.). It is VERY IMPORTANT when installing a propane heater on a 2-stage
regulation system to follow the gas line sizing data in Table 13 without exception.
Table 10
Natural Gas Pipe Sizing, Low-Pressure, Single-Stage Regulation
Distance from Gas
Meter to Heater Gas
Valve Inlet
Model
TR250NA
TR400NA
Btu/hr Input
250,000
400,000
Line Material
Iron or Plastic Pipe
Iron or Plastic Pipe
0 to 50 ft
1”
1-1/4”
50 to 100 ft
1-1/4”
1-1/4”
100 to 200 ft
1-1/4”
1-1/2”
200 to 300 ft
1-1/2”
2”
Based upon an inlet gas pressure of 0.5 psig or less at a pressure drop of 0.50 in-wc
Table 11
Propane Gas Pipe Sizing, Low-Pressure, Single-Stage Regulation
Distance from Tank
Regulator Outlet to
Heater Gas Valve
Inlet
Model
TR250LP
TR400LP
Btu/hr Input
250,000
400,000
Line Material
Iron Pipe
Tubing
Iron Pipe
Tubing
0 to 50 ft
1”
1-1/8”
1”
--
50 to 100 ft
1”
1-1/8”
1-1/4”
--
100 to 200 ft
1-1/4”
--
1-1/4”
--
200 to 300 ft
1-1/4”
--
1-1/2”
--
Based upon an inlet gas pressure of 11 in-wc at a pressure drop of 0.50 in-wc
Table 12
Natural Gas Pipe Sizing, High-Pressure, 2-Stage Regulation
Distance from Outlet
of 1st Stage Regula-
tor to Inlet of 2nd
Stage Regulator
Model
TR250NA
TR400NA
Btu/hr Input
250,000
400,000
Line Material
Iron or Plastic Pipe
Iron or Plastic Pipe
First Stage*
0 to 50 ft
1/2”
1/2”
50 to 100 ft
1/2”
3/4”
100 to 150 ft
1/2”
3/4”
Second Stage**
0 to 10 ft
3/4”
3/4”
*Based upon an inlet gas pressure of 2 psig at a pressure drop of 1 psi
**Based upon an inlet gas pressure of 10 in-wc at a pressure drop of 0.50 in-wc
