Natural Gas Connections; Natural Gas Piping Sizes; Natural Gas Piping Connections; Natural Gas Supply Pressure Requirements - Watts AERCO Modulex EXT Commercial Series User Manual

Modulex EXT Commercial Series Boilers User Manual
CHAPTER 4: Installation Instructions

4.9.1 Natural Gas Connections

4.9.1.1

Natural Gas Piping Sizes

Contact your local gas supplier for natural gas pipe sizes and meter types.
4.9.1.2

Natural Gas Piping Connections

The boiler gas pipe is equipped with external 3'' ASME B16.5 flange, onto which the tail
piece of the gas shut off valve can be connected. Use appropriate sealing.
The connection to the boiler must include a suitable method of disconnection and a gas
control valve must be installed adjacent to the boiler for isolation purposes.
4.9.1.3

Natural Gas Supply Pressure Requirements

The nominal inlet working gas pressure measured at the boiler should be 7" W.C. (18 mbar)
for natural gas. Maximum pressure with no flow (lockup) or with the boiler running is 10.5
inches W.C. Minimum pressure with gas flowing (verify during boiler startup) is 4.0 inches
W.C.

4.9.2 Propane Gas Connections

4.9.2.1

Propane Gas Piping Sizes

Contact your local gas supplier for Propane gas pipe sizes, tanks, and 100% lockup gas
pressure regulator.
4.9.2.2

Propane Gas Piping Connections

The boiler pipe is provided with external 3'' ASME B16.5 flange, onto which the tail piece of
the gas shut off valve can be screwed. Use appropriate sealing.
The connection to the boiler must include a suitable method of disconnection. Use a gas shut
off valve compatible with propane gases. A sediment trap must be provide upstream of the
gas controls.
4.9.2.3

Propane Gas Supply Pressure Requirements

Pressures required at gas valve inlet pressure port:
•
Nominal gas pressure is 11 inches W.C.
•
Maximum gas pressure is 13 inches W.C. with no flow (lockup) or with boiler
running.
•
Minimum gas pressure is 8 inches W.C. with gas flowing (verify during boiler
startup).
NOTE:
Ensure that the high gas pressure regulator is installed at least 6 to 10 feet upstream of the boiler.
Page 32 of 144
09/15/2017
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Phone: 800-526-0288
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