Installation Instructions

48
Reference Data
SPECIFIED GRAVITY FACTOR FOR NATURAL GAS
Pressure Conversion Factors Fuel Gas Information
1/4 psi = 6.921 in. w.c. = (approx. 7” w.c.)
1/2 psi = 13.842 in. w.c. = (approx. 14” w.c.)
1 psi = 27.684 in w.c. = (approx. 28” w.c.)
2 psi = 55.368 in. w.c. = (approx. 56” w.c.)
5 psi = 138.42 in. w.c. = (approx. 140” w.c.)
Note: to determine the CFH for Natural Gas, divide the BTU load by 1000. To
determine the CFH for Propane, divide the BTY by 2516.
Natural Gas Propane
BTU per Cubin Foot = 1000 2516
Specific Gravity = 0.60 1.52
Gas piping systems that are to be supplied with a gas of a specific gravity other than 0.60
for natural gas or 1.52 for propane shall apply a specific gravity factor. This conversion is
accomplished by multiplying the flo
w capacities given in Tables 1 through 15 and on the
pressure drop graph by the appropriate multiplier shown in the tables shown below. If the
exact specified gravity is not shown in the table, use the next higher specified gravity
shown.
Specific Gravity Multiplier Specific Gravity Multiplier
0.35 1.31 1.00 0.78
0.40 1.23 1.10 0.74
0.45 1.16 1.20 0.71
0.50 1.10 1.30 0.68
0.55 1.04 1.40 0.66
0.60 1.00 1.50 0.63
0.65 0.96 1.60 0.61
0.70 0.93 1.70 0.59
0.75 0.90 1.80 0.58
0.80 0.87 1.90 0.56
0.85 0.84 2.00 0.55
0.90 0.82 2.10 0.54