19
Weil-McLain Ultra Oil NX
Burner Manual
Perform the following steps when replacing a nozzle.
Remove the nozzle line assembly to gain access to
the nozzle.
Use a 3/4” open-end wrench to hold the nozzle
adapter. DO NOT attempt to remove or replace
the nozzle without securing the adapter, as nozzle
alignment could be seriously affected.
Do not squeeze the electrodes when handling the
nozzle line assembly. Excessive force could change
the electrode tip settings or damage the ceramic
electrode insulators.
Use a 5/8” open-end wrench to carefully remove the
existing nozzle.
Inspect the nozzle adapter before installing the
new nozzle. If it is grooved or scratched on the
sealing surface, replace the nozzle line assembly.
If the surface is damaged, oil could leak at the
nozzle to adapter joint, causing serious combustion
problems.
Protect the nozzle ori
fi
ce and strainer when
installing. If the ori
fi
ce gets dirt in it or is scratched,
the nozzle will not function properly.
1.
2.
3.
4.
5.
6.
5/32” GAP
1/4” above
nozzle center
3/32” Nozzle-to-tip
Spacing
SK9664
Nozzle
fl
ow rate U. S. gallons per hour of No. 2 fuel oil when
pump pressure (psig) is:
Nozzle
size
(rated at
100 psig)
125
psi
140 psi
(factory
std.)
150
psi
175 psi
200
psi
0.40
0.45
0.47
0.49
0.53
0.56
0.50
0.56
0.59
0.61
0.66
0.71
0.60
0.67
0.71
0.74
0.79
0.85
0.65
0.73
0.77
0.80
0.86
0.92
0.75
0.84
0.89
0.92
0.99
1.06
0.85
0.95
1.01
1.04
1.13
1.20
0.90
1.01
1.07
1.10
1.19
1.27
1.00
1.12
1.18
1.23
1.32
1.41
1.10
1.23
1.30
1.35
1.46
1.56
1.20
1.34
1.42
1.47
1.59
1.70
1.25
1.39
1.48
1.53
1.65
1.77
1.35
1.51
1.60
1.65
1.79
-
1.50
1.68
1.77
1.84
-
-
1.65
1.84
-
-
-
-
1.75
-
-
-
-
-
Table 6 - Nozzle Flow Rate by Size
Figure 12. – Electrode tip gap and spacing
To install a new nozzle, place a 3/4” open-end
wrench on the nozzle adapter. Insert the nozzle
into the adapter and secure
fi
nger tight. Finish
tightening with a 5/8” open-end wrench. Use care
to avoid bending the burner head support legs or
electrodes.
Do not over-torque the nozzle when installing. This
will cause deep grooves in the nozzle adapter,
preventing a seal when a new nozzle is installed.
Carefully check and realign the electrode tips after
replacing a nozzle, ensuring the electrode settings
comply with Figure 12.
If the head was removed when replacing the
nozzle, carefully reconnect the head to the nozzle
adapter. Make sure to align the key in the support
leg with the keyway in the nozzle adapter and
to butt the head support to the nozzle adapter
shoulder, see Figure 10.
Check/Adjust Electrodes
Check the electrode tip settings, as shown in Figure 12.
If necessary, adjust by loosening the electrode clamp
screw (Figure 10) and slide/rotate the electrodes as
necessary. When the adjustment is complete, securely
tighten the clamp screw.
Note that if the throttle cup is moved be sure to
reposition it with no gap between the nozzle adapter and
hub.
7.
8.
9.
10.
Section: Trained Service Technician’s Regular Maintenance
Summary of Contents for UO-3 CV
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