MACH® Series
Gas-Fired Boiler
Installation
Page 13
3.7
G
AS
P
IPING
Before making the gas hook-up, make sure the boiler
is being supplied with the type of fuel shown on the
boiler nameplate.
The boiler shall be installed such that the gas ignition
system components are protected from water
(dripping, spraying, rain, etc.) during appliance
operation and service (circulator replacement, control
replacement, etc.)
The boiler is factory fire-tested and adjusted for proper
combustion with natural gas supply pressure of 7”
W.C. Typical gas pressure supply for natural gas is
7" W.C. The gas train components are certified to
handle a maximum inlet pressure of 14" W.C. (1/2
psig.). If the available gas pressure exceeds 14" W.C.,
a suitable additional intermediate gas pressure
regulator of the "lock up" type must be provided to
reduce the pressure to less than 14" W.C.
WARNING!
All threaded connections must be made using a
pipe compound that is resistant to the action of
liquefied petroleum gases.
Do not use Teflon
tape on gas line threads.
In the Commonwealth of Massachusetts, the gas cock
must be a “T-handle type.”
RECOMMENDED GAS PIPING INSTALLATION
Install a sediment trap (drip leg) and a union
connection upstream of the primary manual shutoff
valve on the boiler. Gas piping should be installed in
accordance with National Fuel Gas Code, ANSI
Z223.1, latest edition, and any other local codes
which may apply. In Canada, please refer to CSA-
B.149.
Notic
e
:
See Pipe Capacity for Natural Gas chart on
the following page for required pipe size, based on
overall length of pipe from meter plus equivalent
length of all fittings. Approximate sizing may be
based on 1 cubic foot of natural gas per 1,000 Btu per
hour input, i.e., 500,000 Btu per hour requires about
500 cubic feet per hour. (See "Typical Boiler
Operating Conditions," Section 4.3, for more
information.)
Boiler Main Gas
Valve
Gas
Supply
Union
Drip Leg
Remote Gas
Shutoff
Meter
Field Gas Piping
