Amana GUIA Series Service Instructions Manual page 57

PRODUCT DESIGN
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Length of Nominal Black Pipe Size
Pipe in Feet 1/2" 3/4"
10 132 278
20 92 190
30 73 152
40 63 130
50 56 115
60 50 105
70 46 96
80 43 90
90 40 84
100 38 79
(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on 0.60 Specific
Gravity Gas)
BTUH Furnace Input
CFH =
Heating Value of Gas (BTU/Cubic Foot)
To connect the furnace to the building's gas piping, the in-
staller must supply a ground joint union, drip leg, manual
shutoff valve, and line and fittings to connect to gas valve.
In some cases, the installer may also need to supply a tran-
sition piece from 1/2" pipe to a larger pipe size.
The following stipulations apply when connecting gas pip-
ing. Refer to the following figures for typical gas line con-
nections to the furnace.
1. Use black iron or steel pipe and fittings for the building
piping.
2. Use pipe joint compound on male threads only. Pipe
joint compound must be resistant to the action of the
fuel used.
3. Use ground joint unions.
4. 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.
5. Install a 1/8" NPT pipe plug fitting, accessible for test
gage connection, immediately upstream of the gas sup-
ply connection to the furnace.
6. Use two pipe wrenches when making 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.
7. 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.
8. Tighten all joints securely.
9. Connect the furnace to the building piping by one of the
following methods:
1" 1 1/4" 1 1/2"
520 1050 1600
350 730 1100
285 590 980
245 500 760
215 440 670
195 400 610
180 370 560
170 350 530
160 320 490
150 305 460
– Rigid metallic pipe and fittings.
– Semi-rigid metallic tubing and metallic fittings. Alu
minum 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.
10. Use listed gas appliance connectors in accordance with
their instructions. Connectors must be fully in the same
room as the furnace.
11. Protect connectors and semi-rigid tubing against physi-
cal and thermal damage when installed. Ensure alumi-
num-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.
CAUTION
Edges of sheet metal holes may be sharp. Use gloves
as a precaution when removing hole plugs.
Direct/Standard Inlet Piping
When gas piping enters directly to the gas valve through
the standard inlet hole (upflow through the right side panel),
the installer must supply straight pipe with a ground joint
union to reach the exterior of the furnace. NOTE: The rigid
pipe must be long enough to reach the outside of the cabi-
net to seal the grommet cabinet penetration on the 90% &
95% furnaces. A semi-rigid connector to the gas piping can
be used outside the cabinet per local codes.
Indirect/Alternate Inlet Piping
When gas piping enters indirectly to the gas valve through
the alternate gas inlet hole the installer must supply the
following fittings (starting from the gas valve) to reach the
outside of the cabinet (NOTE: On the 90% & 95% furnaces
the installer must swap the alternate inlet hole plug with the
standard inlet grommet in order to seal the cabinet):
• Coupling.
• 90 degree elbow.
• 2 inch close nipple.
• 90 degree elbow.
• Straight pipe, with a ground joint union, to reach the
exterior of the furnace. NOTE: The rigid pipe must
be long enough to reach the outside of the cabinet
so as to seal the grommet cabinet penetration on the
90% & 95% furnaces. A semi-rigid connector to the
gas piping can be used outside the cabinet per local
codes.
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