Intertek ACVC96 Service Instructions Manual page 28

INSTALLATION CONSIDERATIONS
GAS PIPING CONNECTIONS
T
O AVOID POSSIBLE UNSATISFACTORY OPERATION OR EQUIPMENT DAMAGE
DUE TO UNDERFIRING OF EQUIPMENT, USE THE PROPER SIZE 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.
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Length of
Pipe in Feet 1/2"
10 132
20 92
30 73
40 63
50 56
60 50
70 46
80 43
90 40
100 38
(Pres sure 0. 5 ps ig 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 transi-
tion piece from 1/2" pipe to a larger pipe size.
The following stipulations apply when connecting gas piping.
Refer to the following figures for typical gas line connections
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.
28
CAUTION
Nominal Black Pipe Size
3/4" 1" 1 1/4"
278 520 1050
190 350 730
152 285 590
130 245 500
115 215 440
105 195 400
96 180 370
90 170 350
84 160 320
79 150 305
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
supply 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 in-
stalled, the union must be downstream of the manual
shutoff valve, between the shutoff valve and the fur-
nace.
8. Tighten all joints securely.
1 1/2"
1600
1100
980
760
670
610
560
530
490
460