Gas Piping Connections - Amana MVM97 Installation Instructions Manual

Gas Piping Connections

T
O AVOID POSSIBLE UNSATISFACTORY OPERATION OF EQUIPMENT
DAMAGE DUE TO UNDERFIRING OR EQUIPMENT
/
OF NATURAL PROPANE GAS PIPING NEEDED WHEN RUNNING PIPE FROM
/
THE METER TANK TO THE FURNACE
The gas piping supplying the furnace must be properly
sized based on the gas flow required, specific gravity of
the gas, and length of the run. The gas line installation
must comply with local codes, or in their absence, with
the latest edition of the National Fuel Gas Code, NFPA 54/
ANSI Z223.1 or CAN/CSA B149.1-15 in Canada.
Natural Gas Capacity of Pipe In Cubic Feet of Gas Per Hour (CFH)
Nominal ½ ¾
0.622 0.824
Actual ID:
Capacity in Cubic Feet of Gas per Hour
Length (ft)
10 170 360
20 118 247
30 95 199
40 81 170
50 72 151
60 65 137
70 60 126
80 56 117
90 52 110
100 50 104
125 44 92
150 40 83
175 37 77
200 34 71
250 30 63
This chart refers to natural gas w ith an inlet pressure of less than 2 psi and a
pressure drop of 0.5" W.C. Specific gravity is 0.60.
CFH =
Heating Valve of Gas (BTU/Cubic Foot)
To connect the furnace to the building's gas piping, the
installer 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 transition piece from 1/2" pipe to a larger pipe
size.
The following stipulations apply when connecting gas pip-
ing. Refer to Gas Piping Connections figure for typical gas
line connections to the furnace.
• Gas piping must be supported external to the furnace
cabinet so that the weight of the gas line does not
distort the burner rack, manifold or gas valve.
• 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.
WARNING
,
USE THE PROPER SIZE
.
Pipe Size (in.)
1 1¼ 1½ 2
1.049 1.380 1.610 2.067
678 1390 2090 4020
466 957 1430 2760
374 768 1150 2220
320 657 985 1900
284 583 873 1680
257 528 791 1520
237 486 728 1400
220 452 677 1300
207 424 635 1220
195 400 600 1160
173 355 532 1020
157 322 482 928
144 296 443 854
134 275 412 794
119 244 366 704
BTUH Furnace Input
• 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 mini-
mum 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, acces-
sible for test gage connection, immediately upstream
of the gas supply connection to the furnace.
• Always use a back-up wrench when making the con-
nection 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; ex-
cessive over-tightening may damage the gas valve.
• Install a manual shutoff valve between the gas me-
2½
ter and unit within six feet of the unit. If a union
2.469
is installed, the union must be downstream of the
6400
manual shutoff valve, between the shutoff valve and
4400
the furnace.
3530
• Tighten all joints securely.
3020
• Connection method must be in compliance with all
2680
local and national codes. US: National Fuel Gas Code
2430
(NFGC) NFPA 54-2012/ANSI Z223.1-2012 and the In-
2230
stallation Standards, Warm Air Heating and Air Condi-
2080
tioning Systems ANSI/NFPA 90B.
1950
1840 • In Canada, CANADA: National Standard of Canada,
1630
Natural Gas and Propane Installation Code (NSCNGPIC)
1480
CSA B149.1-15.
1360
• Connect the furnace to the building piping by one of
1270
the following methods:
1120
– Rigid metallic pipe and fittings.
– Semi-rigid metallic tubing and metallic fittings.
Aluminum alloy tubing must not be used in exte-
rior locations. In order to seal the grommet cabi-
net 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.