Amana MEC96 Series Manual page 27

• Use black iron or steel pipe and fittings for building
piping. Where possible, use new pipe that is properly
chamfered, reamed, and free of burrs and chips. If old
pipe is used, be sure it is clean and free of rust, scale,
burrs, chips, and old pipe joint compound.
• Use pipe joint compound on male threads ONLY.
Always use pipe joint compound (pipe dope) that
is APPROVED FOR ALL GASES. DO NOT apply
compound to the first two threads.
• Use ground joint unions.
• 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.
• 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.
• 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.
The gas piping may enter the left or right side of the
furnace cabinet. The installer must supply rigid pipe long
enough to reach the outside of the cabinet to seal the
grommet cabinet penetration. A semi-rigid connector to the
gas piping can be used outside the cabinet per local codes.
1/2" NPT pipe and fittings are required. For models with an
"L" shaped manifold, a 4 1/2" long nipple is required. For
models with a hook shaped manifold, a 2" long nipple is
required.
A semi-rigid connector to the gas piping can be used
outside the cabinet per local codes. From the elbow, the
length of pipe and the fittings required will vary by the side
chosen, location of union and cabinet width. The union
may be placed inside or outside of the cabinet.
Alternate Manifold
Gas Line
Location
Gas Valve
*Ground
Joint
Pipe
Union
*NOTE: Union may be inside furnace cabinet where allowed by local codes.
Gas Connections
To avoid the possibility of explosion or fire, never use a
match or open flame to test for leaks.
Gas Piping Checks
Before placing unit in operation, leak test the unit and gas
connections.
Check for leaks using an approved chloride-free soap and
water solution, an electronic combustible gas detector, or
other approved testing methods.
NOTE: Never exceed specified pressures for
testing. Higher pressure may damage the gas valve
and cause subsequent overfiring, resulting in heat
exchanger failure.
Disconnect this unit and shutoff valve from the gas supply
piping system before pressure testing the supply piping
system with pressures in excess of 1/2 psig (3.48 kPa).
Isolate this unit from the gas supply piping system by
closing its external manual gas shutoff valve before
pressure testing supply piping system with test pressures
equal to or less than 1/2 psig (3.48 kPA).
27
Burners Manual Shut Off Valve
(upstream from
ground joint
pipe union)
*Ground
Joint
Pipe
Union
Drip Leg
Grommet
in Standard
Gas Line
Hole
UPFLOW
Figure 39
WARNING