2900 Selma Highway, Montgomery AL 36108 USA
PH: +1.334.386.5400 (option 2) FAX: +1.334.386.5450 WEB: www.hartzell.aero
Page | 25
MM10001
Dated 1/1/08
Rev L dated 5/21/15
• Visible wear of the Durakoat coating that is visible on the lower half of the flame
tube. (If wear is evident, it is recommended that the tube be replaced)
• Soft and spongy areas due to overheating.
• Deformation due to overheating or backfiring, fatigue cracks and pin holes.
• Perform a pressure decay test as described under 'Pressure Decay Test and
Combustion Air Switch Test'.
9.3.2 INSPECTION OF FUEL SUPPLY
NOTE: Any evidence of distortion or damage is reason for replacement of the nozzle assembly.
CAUTION: FUEL NOZZLE CLEANING: Do not scrape or buff deposits off the nozzle face.
Do not press or tap on the nozzle face. Cleaning the nozzle is not recommended.
CAUTION: Do not use Teflon products as sealer for fuel fittings.
9.3.2.1 Replace fuel nozzle at 2000hr/10yr overhaul.
9.3.2.2 Inspect threads, etc., on the fuel feed and fuel nozzle holder assembly. Check
for cracks or a distorted holder. Replace if any are evident.
9.3.2.3 Check fuel spray pattern using appropriate line pressure as outlined in section
9.3.3.
9.3.2.4 Check the solenoid by reading the resistance across the two leads with an ohm
meter. A reading of 40-45 ohms for 24-volt, 10-14 ohms for 12-volt at room
temperature is normal. Replace if out of limits.
9.3.2.5 NOZZLE HOLDER ASSEMBLY INTEGRITY TEST
After removing the nozzle, apply 100 PSI of filtered compressed air to drain
port which is located on the surface of the fuel feed and nozzle holder
assembly near the threaded nozzle cavity. (See Figure 18)
Submerge in water, with the fuel inlet and nozzle cavity left open.
Check for bubbles, which would indicate leakage. If bubbles appear at
either the nozzle cavity or the fuel inlet, there is a leak in the fuel tube. If
bubbles appear externally at either end of the shroud tube, the shroud tube is
leaking. Replace the whole assembly.
If no leaks are detected, dry the assembly carefully with compressed air.
To Next Page
Loading...