Oil Supply Lines Sizing - Lennox OHR23-105 Installation Instructions Manual

every foot of horizontal run. Flue pipe or vent connec-
tor must be inserted into but not beyond the outside
wall of the chimney flue.
Where two or more appliances vent into a common flue,
the area of the common flue should be at least equal to the
area of the largest flue or vent connector, plus 50% of the
area of any additional flues or vent connectors.
Inspect flue pipe annually. Clean soot or ash from flue pipe,
if necessary. If pipe is rusted, replace.
Radiation Shield Installation
COMBUSTIBLE
Ï Ï Ï Ï Ï Ï Ï Ï
MATERIAL
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OHR23 UNIT (TOP)
Ï Ï Ï Ï Ï Ï Ï Ï
RADIATION
UNIT SHIELDS
Ï Ï Ï Ï Ï Ï Ï Ï
CABINET
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
A
NON−
COMBUSTIBLE
SEE NOTE 2
SPACERS
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
Ï Ï Ï Ï Ï Ï Ï Ï
OHR23 UNIT (FRONT)
Ï Ï Ï Ï Ï Ï Ï Ï
NOTE 1−Radiation shields must be constructed of 24 gauge sheet metal minimum.
NOTE 2−Radiation shields required when A is less than 9" (229mm).
NOTE 3−Radiation shields should extend from the top of the unit to the top of the flue pipe.
Figure 15

Oil Supply Lines Sizing

Ensure that the restrictions of the piping system, plus any
lift involved, do not exceed the capability of the oil pump.
Use the following guidelines when determining whether to
use a single−or two−stage oil pump.
One−Pipe System
When using a one−pipe system with the oil tank even above
the burner and a vacuum of 6" (152 mm) Hg or less, a single−
stage fuel pump with a supply line and no return line should
be adequate. See figure 16. Manual bleeding of the fuel
pump is required on initial start up. Failure to bleed air from
the oil pump could result in an air lock/oil starvation condition.
1" (25mm)
min
12"
(305mm)
7" (178
mm)
A
RADIATION SHIELDS
(SEE NOTE 1)
B
FLUE
SEE NOTE 3
PIPE
NOTE − As an extra precaution, cycle heating on and off
ten times after bleeding air from the oil pump. This will
eliminate air in the gun assembly.
Oil Piping
air
vent
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
fill
pipe
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Line Length
0−50' (15 m)
51−100' (15 m)
Two−Pipe System
When using a two−pipe system with the oil tank below the
level of the burner, a single−stage fuel pump should be
used in lift conditions of up to 10 feet (3 m) and/or a vacu-
um of 10" (254 mm) Hg or less. See figure 17. Use a two−
stage fuel pump when lift exceeds 10 feet (3 m) and/or a
vacuum of 10" (254 mm) Hg to 15" (381 mm) Hg. Both con-
ditions require that you use a two−pipe system, which con-
sists of a return line that purges the fuel pump of air by return-
ing it to the tank. To determine the run and lift for piping, refer
to table 5 .
To determine the length of the run for piping, refer to table 4 .
Oil Piping Two-Pipe System
Air Vent
Fill
Pipe
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Oil
Tank
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó Ó
Return
pipe
outside tank fuel pump above bottom of tank.
Page 12
One-Pipe System
fuel
pump
Oil
Tank
Shut−off
Valve
Figure 16
Table 4
One−pipe Oil Sizing
Pipe Diameter (OD Tubing)
3/8" (10 mm)
1/2" (12 mm)
Return
pipe
3"−4" (76 mm −102 mm)
R
Figure 17
Aux
Filter
8 FT (2.4 M)
MAXIMUM
ONE PIPE LIFT
fuel
pump
Aux
Filter
Inlet
H