MACH® Series
Gas-Fired Boiler
Installation
20
6. After it has been determined that each appliance remaining connected to the common venting system properly
vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas-
burning appliance to their previous conditions of use.
Any improper operation of the common venting system should be corrected so the installation conforms to the
National Fuel Gas Code, ANSI Z223.1 and CSA B149 Installation Code. When resizing any portion of the common
venting system, the common vent system should be resized to approach the minimum size as determined using the
appropriate tables in part 11 of the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or CAN/CSA B149.1 Natural
Gas and Propane Installation Code.
3.6 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. The gas train components are certified to handle
a maximum inlet pressure of 14" W.C. (1/2 psig.). Typical gas pressure supply for natural gas is 7" W.C. (11" W.C. for
propane). 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. This boiler requires a minimum inlet
gas pressure of 3.5” W.C
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.
Install a sediment trap (drip leg) and a union connection ahead of the primary manual shutoff valve on the boiler. A
gas piping schematic is shown below. 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 see CAN/CSA-B.149.1, latest
edition. In the Commonwealth of Massachusetts, the gas cock must be a “T-handle type.”
RECOMMENDED GAS PIPING INSTALLATION
NOTICE!
See Pipe Capacity for Natural Gas chart on he 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., 2,500,000 Btu per hour requires about 2,500 cubic feet per hour.
(See "Typical Boiler Operating Conditions," Section 4.4 for more information.)
Boiler Main Gas
Valve
Gas
Supply
Union
Drip Leg
Remote Gas
Shutoff
Meter
Field Gas Piping
