Operating instructions
68
NATURAL GAS
Length of Pipe 
- Ft.
Pipe Capacity - BTU Per Hour Input Includes Fittings
1/2” 3/4” 1” 1 1/4”
20 92,000 190,000 350,000 625,000
40 63,000 130,000 245,000 445,000
60 50,000 105,000 195,000 365,000
PROPANE GAS
Length of Pipe 
- Ft.
Pipe Capacity - BTU Per Hour Input Includes Fittings
Copper Tubing 
(Outside Diameter)
Iron Pipe
5/8” 3/4” 1/2” 3/4”
20 131,000 216,000 189,000 393,000
40 90,000 145,000 129,000 267,000
60 72,000 121,000 103,000 217,000
• ANSI - American National Standards Institute, Inc. 
oversees creation and maintenance of voluntary 
consensus standards, including ANSI Z21.13/CSA 4.9: 
Gas-Fired Low Pressure Steam and Hot Water Boilers.
• ASTM - American Society for Testing and Materials. 
ASTM International is one of largest voluntary standards 
development organizations in world trusted source for 
technical standards for materials, products, systems, 
and services. Known for their high technical quality and 
market relevancy, ASTM International standards have 
important role in information infrastructure that guides 
design, manufacturing and trade in the global economy. 
• AUTHORITY HAVING JURISDICTION - Individual 
or organization adopting and enforcing codes, rules, 
and by-laws governing various concerns of community. 
Commonly referred to as "nal authority" for any matters 
relating to LIFE SAFETY and BUILDING CONSTRUCTION 
within a community.
• Btu - Abbreviation for British Thermal Unit. Quantity of 
heat required to raise temperature of 1 pound of water 
1°F.
• BURNER - Device for nal conveyance of gas or mixture 
of gas and air, to combustion zone.
• COMBUSTION - Rapid oxidation of fuel gases 
accompanied by production of heat or heat and light. 
Complete combustion of fuel is possible only in presence 
of adequate supply of oxygen.
• COMBUSTIBLE MATERIAL - Materials made of or 
surfaced with wood, compressed paper, plant bers, 
or other materials capable of being ignited and 
burned. Such material shall be considered combustible 
even though ame-proofed, re-retardant treated, or 
plastered.
• CONDENSATE - Liquid separated from ue gas due to 
reduction in temperature.
• DIRECT VENT BOILER - Boiler constructed and installed 
so all combustion air is derived directly from outdoors 
and all vent gases are discharged to outdoors.
• DRAFT - Pressure difference causes gases or air to ow 
through a chimney, vent, ue or appliance.
• FLA - Full load amps.
• FLUE GASES - Products of combustion plus excess air 
in appliance ues or heat exchanger.
• HIGH-VOLTAGE - Circuit involving potential of not more 
than 600 volts and having circuit characteristics in excess 
of those of low-voltage circuit.
• IGNITER - Device utilizing electrical energy to ignite gas 
at main burner.
• LEAK CHECK - Operation performed on gas piping sys-
tem to verify system does not leak.
• LOW WATER CUTOFF - Device constructed to 
automatically cut off fuel supply when surface of water in 
boiler falls to lowest safe water level. 
• LOW-VOLTAGE - Circuit involving potential of not more 
than 30 volts.
• METRIC GAS METERS
MBH =
127,116 x cu meters
 Seconds
For example: Gas Meter measures 0.1 cubic Meters in 100 
 seconds
MBH =
127,116 x 0.1
 = 127 MBH
100
• PRESSURE TEST - Operation performed to verify gas 
tight integrity of gas piping following its installation or       
modication.
• PURGE - To free gas conduit of air or gas, or mixture of 
gas and air. 
• PURGE TIME - Period of time intended to allow for 
dissipation of any unburned gas or residual products of 
combustion.
• GAS PIPE SIZES - Table 14
15 - GLOSSARY










