28
•
Use pipe joint compound on male threads ONLY. Always
use pipe joint compound (pipe dope) that is APPROVED
FOR ALL GASSES. 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.
•
Connection method must be in compliance with all
local and national codes. US: National Fuel Gas Code
(NFGC) NFPA 54-2015/ANSI Z223.1-2015 and the
Installation Standards, Warm Air Heating and Air
Conditioning Systems ANSI/NFPA 90B.
CANADA: National Standard of Canada, Natural Gas
and Propane Installation Code (NSCNGPIC) CAN/CSA
B149.1-15.
•
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.
½
”
¾
”
1
”
1¼”
1 ½”
10
132
278
520
1050
1600
20
92
190
350
730
1100
30
73
152
285
590
980
40
63
130
245
500
760
50
56
115
215
440
670
60
50
105
195
400
610
70
46
96
180
370
560
80
43
90
170
350
530
90
40
84
160
320
490
100
38
79
150
305
460
CFH = BTUH Furnace Input ________
_________
Heating Value of Gas (BTU/Cubic Foot)
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Nominal Black Pipe Size
Length of
Pipe in Feet
(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on
0.60 Specific gravity Gas)
Gas Piping Connections
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.
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
Gas Line
Location
Gas Valve
Burners
Manual Shut Off Valve
(upstream from
ground joint
pipe union)
Drip Leg
Grommet
in Standard
Gas Line
Hole
*Ground
Joint
Pipe
Union
*Ground
Joint
Pipe
Union
*NOTE: Union may be inside furnace cabinet where allowed by local codes.
Manifold
UPFLOW - Figure 37
