High Altitude Derate; Propane Gas Conversion; Gas Piping Connections - Intertek MVM97 Series Installation Instructions Manual

Inlet gas supply pressures must be maintained within the ranges
specified in the following table. The supply pressure must be con-
stant and available with all other household gas fired appliances
operating. The minimum gas supply pressure must be maintained
to prevent unreliable ignition. The maximum must not be ex-
ceeded to prevent unit overfiring.
H A D
IGH LTITUDE ERATE
In some areas the gas supplier may artificially derate the gas in an effort to compensate for the effects of altitude. If the gas is
artificially derated, the appropriate orifice size must be determined based upon the BTU/ft
altitude. Refer to the National Fuel Gas Code, NFPA 54/ANSI Z223.1 or CAN/CSA B149.1 in Canada, and information provided by the
gas supplier to determine the proper orifice size.
P G C
ROPANE AS ONVERSION
As shipped, this unit is configured for natural gas. The LPM-09
is required to convert this furnace to operate on LP gas.
The correct kit must be used to insure safe and proper furnace
operation. All conversions must be performed by a qualified in-
staller, or service agency.
G V
AS ALVE
This unit is equipped with a 24 volt gas valve which modulates by pneumatic linkage to the combustion air blower. Taps for
measuring the gas supply pressure and manifold pressure are provided on the valve. This is a non-convertible, non-adjustable gas
valve equipped for natural gas.
The gas valve has a manual ON/OFF control located on the valve itself. This control may be set only to the "ON" or "OFF" position.
Refer to the lighting instructions label or the Startup Procedure & Adjustment section of this manual for use of this control during
start up and shut down periods.
G P C
AS IPING ONNECTIONS
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 in Canada.
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 piping. Re-
fer to Gas Piping Connections figure for typical gas line connec-
tions 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.
•
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.
32
Inlet Gas Supply Pressure
Natural Gas Minimum:
Propane Gas Minimum: 11.0" w.c.
3
P ,
OSSIBLE PROPERTY DAMAGE
OCCUR IF THE CORRECT CONVERSION KITS ARE NOT INSTALLED
APPROPRIATE KITS MUST BE APPLIED TO ENSURE SAFE AND PROPER
. A
FURNACE OPERATION LL CONVERSIONS MUST BE PERFORMED BY A
QUALIFIED INSTALLER OR SERVICE AGENCY
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
Natural Gas Capacity of Pipe In Cubic Feet of Gas Per Hour (CFH)
Nominal ½ ¾
Actual ID: 0.622 0.824
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 170 360
20 118 247
30 95 199
40 81 170
50 72 151
60 65 1370
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 with an inlet pressure of less than 2 psi and a pressure
drop of 0.5" W.C. Specific gravity is 0.60.
CFH = BTUH Furnace Input
Heating Valve of Gas (BTU/Cubic Foot)
4.5" w.c. Maximum: 10.0" w.c.
Maximum: 13.0" w.c.
content of the derated gas and the
WARNING
PERSONAL INJURY OR DEATH MAY
.
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
. T
HE
2½
2.469
6400
4400
3530
3020
2680
2430
2230
2080
1950
1840
1630
1480
1360
1270
1120