FUEL SYSTEM - N.11
An
atomiser
requires
attention
if
(a),
when
proceeding as above it throws out "solid" wet jets and
not broken up spray or, (b), if any of the holes are
choked or partially choked so that the spray issues only
from one or two holes in the nozzle, or (c), an irregular
spray pattern is formed.
Atomiser Dismantling
The atomiser should be placed on a suitable holding
plate, nozzle downwards, first remove the nozzle holder
cap nut (1), slacken the locknut (3), release the nozzle
spring tension by turning the spring cap (4) in an anti-
clockwise direction. Reverse the position of the atomiser
on the holding plate and remove the nozzle cap nut (11)
and nozzle (10) taking care not to drop the nozzle
needle onto the floor. Complete the dismantling by
removing the spring cap, spring (6) and spindle (7).
Inspect visually for signs of corrosion, distortion, etc.
Keep all the dismantled parts together, if possible, in a
tray to facilitate re-assembly after cleaning.
NOTE: Do not lose the small steel shim washer
fitted between the top of the spring and the spring
cap.
To hold the nozzle holder cap nut in a vice or to use
badly worn or adjustable spanners is to invite trouble.
Inspection
The nozzle needle should be free from all traces of
damage, it is important that it is not "blued" at the tip due
to overheating. If the nozzle is "blued" or the seating
has a dull circumferential ring indicating wear or pitting,
the complete unit (nozzle and needle) should be set
aside for attention by a depot or agent with specialized
equipment available and a replacement nozzle assembly
used
The stem of the nozzle needle should be clean and
bright, free from high spots, bad scratches or dull
patches, and the grooves free from foreign matter of any
kind; similarly the nozzle needle bore in the nozzle body
should be free from any of the above, the small drilled
passages should be checked to see that they are clear.
Cleaning
Starting with the nozzle assembly, remove the
needle from the nozzle body and by using the soft brass
seat scraper (ET 070) any carbon which may be present
on the nozzle body seat can be
Fig. N.16. Cleaning the Nozzle.
