Intertek MVM97 Series Installation Instructions Manual page 33

•
Install a drip leg to trap dirt and moisture before it can enter the gas valve. The drip leg must be a minimum of three inches
long.
•
A line pressure test port is provided on the gas valve. If desired, install a 1/8" NPT pipe plug fitting, accessible for test
gage connection, immediately upstream of the gas supply connection to the furnace.
•
Always use a back-up wrench when making the connection to the gas valve to keep it from turning. The orientation of the gas
valve on the manifold must be maintained as shipped from the factory. Maximum torque for the gas valve connection is 375
in-lbs; excessive over-tightening may damage the gas valve.
•
Install a manual shutoff valve between the gas meter and unit within six feet of the unit. If a union is installed, the union must
be downstream of the manual shutoff valve, between the shutoff valve and the furnace.
•
Tighten all joints securely.
•
Connection method must be in compliance with all local and national codes. US: National Fuel Gas Code (NFGC) NFPA
54-2012/ANSI Z223.1-2012 and the Installation Standards, Warm Air Heating and Air Conditioning Systems ANSI/NFPA
90B.
In Canada, CANADA: National Standard of Canada, Natural Gas and Propane Installation Code (NSCNGPIC) CSA B149.1-
2010.
Connect the furnace to the building piping by one of the following methods:
–
Rigid metallic pipe and fittings.
–
Semi-rigid metallic tubing and metallic fittings. Aluminum alloy tubing must not be used in exterior locations. In order
to seal the grommet cabinet penetration, rigid pipe must be used to reach the outside of the cabinet. A semi-rigid
connector to the gas piping may be used from there.
•
Use listed gas appliance connectors in accordance with their instructions. Connectors must be fully in the same room as the
furnace.
•
Protect connectors and semirigid tubing against physical and thermal damage when installed. Ensure aluminum-alloy tubing
and connectors are coated to protect against external corrosion when in contact with masonry, plaster, or insulation, or
subjected to repeated wetting by liquids such as water (except rain water), detergents, or sewage.
Alternate
Manifold
Gas Line
Location
Gas Valve
*Ground
Joint
Pipe
Union
*NOTE: Union may be inside furnace cabinet where allowed by local codes.
UPFLOW
Figure 35
Gas Piping Connections
Manual Shut Off Valve
Burners
(upstream from
ground joint
pipe union)
*Ground
Joint
Pipe
Union
Drip Leg
Grommet
in Standard
Gas Line
Hole
Manual Shut Off Valve
(upstream from ground joint pipe union)
*Ground
Joint
Pipe Union
Grommet
in Standard
Gas Line
Hole
Drip Leg
*NOTE: Union may be inside furnace cabinet where allowed by local codes.
COUNTERFLOW
Alternate
Gas Line
Location
Plug in
Alternate
Gas Line
Hole
Gas Valve
Burners
Figure 36
*Ground
Joint
Pipe Union
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