Beckett NX User Manual

Page 20

Figure 11. – Nozzle Line/Head/Air Tube Assembly (Low fi ring rate shown.)

Retention Head

Head Support Legs

Electrode Tips

Electrode Clamp

Electrode Bracket

Electrode Insulator

Electrode Extension Rods

Nozzle Adapter

Nozzle

Stops in Retention Ring

Retention Ring

Throttle Ring

Throttle Cup

Nozzle Line

Bulkhead Fitting

SK9666A

Throttle Cup Hub

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 orifi ce and strainer when
installing. If the orifi ce gets dirt in it or is scratched,
the nozzle will not function properly.

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 13.

10.

Check/Adjust Electrodes

Check the electrode tip settings, as shown in Figure
12. If necessary, adjust by loosening the electrode
clamp screw (Figure 11) 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.

○

Section: Perform Regular Maintenance

Check Retention Head Alignment and Cad
Cell Sighting

(Refer to Figure 13.)

The cad cell sighting holes in the throttle cup and
the retention head must be aligned to allow the cad
cell to detect the fl ame. Make sure the stamped key
in the retention head collar lines up with the keyway
in the nozzle adapter when mounting the retention
head. Note that in specifi c applications, the retention
head may not have a sighting hole.

○

Figure 12 - Electrode tip gap and spacing

5/32 GAP

1/4 above

nozzle center

1/8 Nozzle-to-tip

Spacing

5/32” Gap

1/4” Above

nozzle center

3/32” Nozzle-to-tip
spacing