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PART 6 – GAS PIPING
FAILURE TO FOLLOW ALL PRECAUTIONS IN THIS SECTION COULD RESULT IN FIRE,
EXPLOSION, OR DEATH!
A. GAS CONNECTION
The gas supply shall have a maximum inlet
pressure of less than 14" w.c. (3.5 kPa), and
a minimum of 3.5" w.c. (.87 kPa). The entire
piping system, gas meter and regulator must
be sized properly to prevent pressure drop
greater than 0.5" (.12 kPa) as stated in the
National Fuel Gas Code. This information is
listed on the rating label.
It is very important that you are connected to the type of gas noted on the rating plate. “LP” for liquefied
petroleum, propane gas, or “NAT” for natural or city gas. You must not do a gas conversion without an
approved gas conversion kit. Prior to turning the gas on, all gas connections must be approved by the
local gas supplier or utility, in addition to the governing authority.
A gas conversion kit comes with the boiler. Follow the included instructions carefully. Failure to follow gas
conversion instructions could result in property damage, serious injury, or death.
The gas connection on the boiler is 1-1/4” for the Mod Con 300, 1-1/2” for the Mod Con 500, and 2” for
the Mod Con 850. It is mandatory that this fitting is used for connection to a field fabricated drip leg as
shown in the illustration above per the National Fuel Gas Code. You must ensure that the entire gas line
to the connection at the boiler is no smaller than the unit supplied connection.
Once all inspections have been performed, the piping must be leak tested. If the leak test requirement is
at a higher test pressure than the maximum inlet pressure, you must isolate the boiler from the gas line.
To do this, shut the gas off using factory and field-installed gas cocks. Failure to do so may damage the
gas valve. In the event the gas valve is exposed to a pressure greater than ½ PSI, 14" w.c. (3.5 kPa), the
gas valve must be replaced. Never use an open flame (match, lighter, etc.) to check gas connections.
B. GAS PIPING
1. Run the gas supply line in accordance with all applicable codes.
2. Locate and install manual shutoff valves in accordance with state and local requirements.
3. In Canada, the Manual Shutoff must be identified by the installing contractor.
Figure 20 – Gas Connection
Summary of Contents for Mod Con 300 HL
Page 13: ...13 Figure 2 ...
Page 31: ...31 Figure 13 ...
Page 37: ...37 J SIDEWALL VENTING DIAGRAMS Figure 16 Sidewall Venting with Tee and Coupling ...
Page 38: ...38 Figure 17 Sidewall Venting Diagrams ...
Page 39: ...39 K VERTICAL VENTING DIAGRAMS Figure 18 Two Pipe Roof Venting with Tee and Coupling ...
Page 40: ...40 Figure 19 Roof and Sidewall Venting with Stainless Steel ...
Page 44: ...44 E GAS VALVE Figure 21 ...
Page 45: ...45 Figure 22 ...
Page 55: ...55 Figure 28 Mod Con Internal Connection Diagram ...
Page 73: ...73 Figure 32 ...
Page 74: ...74 Figure 33 ...
Page 75: ...75 Figure 34 ...
Page 76: ...76 Figure 35 ...
Page 77: ...77 Figure 36 ...
Page 80: ...80 ...
Page 81: ...81 ...
Page 82: ...82 MAINTENANCE NOTES ...
