13
General
This furnace may be installed for either left or right
side gas entry. A typical gas service hookup is
shown in Figure 9. When making the gas
connection provide clearance between the gas
supply line and the entry hole in the furnace casing
to avoid unwanted noise and/or damage to the
furnace.
All gas piping must be installed in compliance with
local codes and utility regulations. Some local
regulations require the installation of a manual main
shut-off valve and ground joint union external to the
Typical Right Side Entry
furnace. The shut-off valve should be readily
accessible for service and/or emergency use.
Consult the local utility or gas supplier for additional
requirements regarding placement of the manual
main gas shut-off. In the absence of local codes the
gas line installation must comply with the latest edition
of the National Fuel Gas Code (ANSI Z223.1) or
(CAN/CGA B149.1 or .2) Installation Codes.
An 1/8 inch NPT tap must be installed in the gas
line to the unit for use when measuring the gas
supply pressure. The tap should be readily
accessible for service use. A drip leg should be
installed in the vertical pipe run to the unit. Table
4 lists gas flow capacities for standard pipe
sizes as a function of length in typical applications
based on nominal pressure drop in the line.
IMPORTANT NOTES:
1. Gas piping must not be run in or through air
ducts, chimneys, gas vents, elevator
shafts, etc.
2. Compounds used on threaded joints of gas
piping must be resistant to the actions of
liquefied petroleum gases.
3. The main manual gas valve and main power
disconnect to the furnace must be properly
labeled by the installer in case emergency
shutdown is required.
Leak Check
After the gas piping to the furnace is complete,
all connections must be tested for gas leaks. To
check for leaks in gas piping systems, use only
a soap and water solution or other approved
method.
!
CAUTION:
Do not use matches, lighters, candles, or
other sources of open flame to check for
gas leaks.
IMPORTANT NOTE:
When pressure testing the gas supply lines
at pressures greater than 1/2 psig (14 inch
W.C.), the furnace must be disconnected
from the gas supply piping system to prevent
damage to the gas control valve. If the test
pressure is less than or equal to 1/2 psig (14
inch W.C.), the furnace must be isolated
from the gas supply line by closing the
manual shut-off valve.
Table 4. Capacity of Black Iron Gas Pipe
(cu. ft. per hour) for Natural Gas
(specific gravity = .60)
NOMINAL
LENGTH OF PIPE RUN
BLACK IRON
(feet)
PIPE DIAMETER
(in.)
10
20
30
40
50
60
70
80
1/2
130
90
75
65
55
50
45
40
3/4
280
190
150
130
115
105
95
90
1
520
350
285
245
215
195
180
170
1 1/4
1050
730
590
500
440
400
370
350
1 1/2
1600
1100
890
760
670
610
560
530
The cubic feet per hour listed in the table above must be greater than the cubic feet
per hour of gas flow required by the furnace.
To determine the cubic feet per hour of gas flow required by the furnace, divide the
input rate of the furnace by the heating value of the gas:
Cubic Feet Per Hour Required Input To Furnace (Btu/hr)
Heating Value of Gas (Btu/Cu. Ft.)
CAPACITY OF BLACK IRON GAS PIPE (CU. FT. PER HOUR)
FOR NATURAL GAS (SPECIFIC GRAVITY - 0.60)
Figure 9. Typical Gas Service Connection
Ground Joint
Union
Dripleg
Shut-Off Valve
Burner
Assembly
Manifold
Some utilities
require Shut-Off
Valve to be
4 to 5 feet
above floor
Automatic Gas
Valve (with manual
shut-off)
