L.p. Units, Tanks, And Piping - York ZF076 Installation Manual

5725848-XIM-A-0319
in the unit's base. Refer to Figures 13 and 15 to locate these
access openings. Typical supply piping arrangements are
shown in Figures 5 and 6. All shaded items are field-supplied.
If gas supply line is routed through the unit's base ensure that
the burner assembly can be removed for maintenance without
disturbing the supply line. The supply piping and fittings must lie
below the bottom gas manifold to avoid interference with the
burner assembly.
Two grommets are shipped in the blower compartment (in parts
bag taped to the blower housing) of every unit with gas heat
and should be used in the knockouts when the gas piping
penetrates the front of the unit.
After the gas supply piping has been installed, the bottom
opening in the unit should be sealed to prevent water from
leaking into the building.
Gas piping recommendations:
1. A drip leg and a ground joint union must be installed in the
gas piping.
2. When required by local codes, a manual shut-off valve may
have to be installed outside of the unit.
3. Use wrought iron or steel pipe for all gas lines. Pipe
compound should be applied sparingly to male threads
only.
Natural gas may contain some propane. Pro-
pane, being an excellent solvent, will quickly dis-
solve white lead or most standard commercial
compounds. Therefore, a special pipe compound
must be applied when wrought iron or steel pipe
is used. Shellac base compounds such as Gas-
kolac or Stalastic, and compounds such as Rec-
torseal #5, Clyde'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.
14
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warning exactly could result
in serious injury, death or property damage.
Never test for gas leaks with an open flame. use a
commercially available soap solution made specifically
for the detection of leaks to check all connections. A fire
or explosion may result causing property damage,
personal injury or loss of life.
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).
7. 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).
8. A 1/8 inch NPT plugged tap, accessible for test gage
connection, must be installed immediately upstream of the
gas supply connection to the furnace.
Figure 5: External supply connection external shut-off

L.P. units, tanks, and piping

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
1NP0440.
All L.P./propane gas equipment must conform to the safety
standards of the National Fire Protection Association.
For satisfactory operation, adequate L.P./propane gas pressure
must be provided at the unit manifold under full load.
Maintaining proper gas pressure depends on three main
factors:
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