WARNING: Natural gas may contain some propane. Propane,
being an excellent solvent, will quickly dissolve
w h it e l e ad or m os t st an d ar d c om me r ci al
compounds. Therefore, a special pipe compound
must be applied when wrought iron or steel pipe is
used. Shellac base compounds such as Gaskolac
or Stalastic, and compounds such as Rectorseal
#5, Cyde’s or John Crane may be used.
4. All piping should be cleaned of dirt and scale by hammering
on the outside of the pipe and blowing out the loose dirt and
scale. Before initial start-up, be sure that all of the gas lines
external to the unit have been purged of air.
5. The gas supply should be a separate line and installed in
accordance with all safety codes as prescribed under
“Limitations”. After the gas connections have been
completed, open the main shut-off valve admitting
normal
gas pressure to the mains. Check all joints for leaks with
soap solution or other material suitable for the purpose.
NEVER USE A FLAME.
6. The furnace and its individual manual shut-off valve must
be disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in
excess of 1/2 psig (3.48kPa).
The furnace must be isolated from the gas supply piping
system by closing its individual manual shut-off valve
during any pressure testing of the gas supply piping system
at test pressures equal to or less than 1/2 psig (3.48kPa).
7. A 1/8 inch NPT plugged tapping, accessible for test gage
connection, must be installed immediately upstream of the
gas supply connection to the furnace.
L.P. UNITS, TANKS AND PIPING (DCG Models)
All gas heat units are shipped from the factory equipped for
natural gas use only. The unit may be converted in the field for
use with L.P./propane gas with accessory kit model number
1NP0418.
All L.P./propane gas equipment must conform to the safety
standards of the National Fire Protection Association.
For satisfactory operation, L.P./propane gas pressure must be
8.8 inch W.C at the unit under full load. Maintaining proper gas
pressure depends on three main factors:
1. The vaporization rate which depends on (a) the tempera-
ture of the liquid and (b) the “wetted surface” area of the
container or containers.
2. The proper pressure regulation. (Two-stage regulation is
recommended from the standpoint of both cost and effi-
ciency.)
3. The pressure drop in the lines between regulators and
between the second stage regulator and the appliance.
Pipe size required will depend on the length of the pipe run
and the total load of all appliances.
Complete information regarding tank sizing for vaporization,
recommended regulator settings, and pipe sizing is available
from most regulator manufacturers and L.P./propane gas
suppliers.
L.P./propane gas is an excellent solvent and special pipe
compound must be used when assembling piping for this gas
as it will quickly dissolve white lead or most standard
commercial compounds. Shellac base compounds such as
Rectorseal #5 are satisfactory for this type of gas.
Check all connections for leaks when piping is completed,
using a soap solution. NEVER USE A FLAME.
FIG. 7 - BOTTOM SUPPLY CONNECTION
EXTERNAL SHUT-OFF
530.18-N11Y
Unitary Products Group
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