1. Overview

During Ballasting, the AFU(Auto Filter Unit) automatically activates Backflushing when the Filter Element becomes clogged.

📌 Issue:

• If the Teflon Nozzle inside the AFU is worn out, it may fail to make proper contact with the Filter Element.
• This may cause Backflushing to malfunction, leading to persistent filter clogging.

📌 Solution:

• Regularly inspect the Teflon Nozzle for wear and replace it if necessary.
• If immediate replacement is not possible, consider a temporary adjustment to improve Backflushing.
• However, Issues caused by temporary adjustments are NOT covered under warranty, even if within the warranty period.

2. Teflon Nozzle Wear Inspection

1. Remove the Suction Unit from the AFU.
2. Check the wear condition of the Teflon Nozzle:
   • The yellow line in the reference image marks the surface in contact with the Filter Element.
   • The height between the yellow line and the red line should be 38.5 mm.
     
3. Replacement Recommendation:
   • The Teflon Nozzle is a consumable part.
   • If the nozzle is too worn to make proper contact with the Filter Element, replacement is required.

📌 Purchasing Replacement Parts:
For orders, contact hanla@hanlaims.com.

3. Teflon Nozzle Replacement Precautions

1. The Suction Unit and Teflon Nozzle are assembled using:
   • Plain Washer
   • Spring
   • Hex Wrench Bolt
2. Before replacing the nozzle:
   • Use a Vernier Caliper to measure the gap between the Suction Unit and the Teflon Nozzle.
   • Reassemble the new nozzle with the same gap measurement.
   • The standard gap is generally 6 mm or 7.46 mm, but it may vary depending on the vessel's design and operating conditions.

📌 Why?
Maintaining the same gap ensures optimal Backflushing performance.

4. Temporary Adjustment Procedure

If replacement is not immediately possible, condiser the following steps to temporarily adjust the Teflon Nozzle.

📌 Important Notes:

• This is not a permanent solution.
• Replacing the Teflon Nozzle is recommended.
• Issues caused by temporary adjustments are NOT covered under warranty, even if within the warranty period.

Step 1: Increase the Gap

1. Measure the gap between the Suction Unit and Teflon Nozzle using a Vernier Caliper.
2. Remove the Teflon Nozzle from the Suction Unit.
3. Add 1 Plain Washer to each location where the Teflon Nozzle is attached.
   • This increases the gap and prevents bolt loosening.
   • The number of Plain Washers may vary depending on on-site conditions.
     

Step 2: Reassemble the Teflon Nozzle

1. Reinstall the Teflon Nozzle onto the Suction Unit.
2. Adjust the gap:
   • If the original gap was approximately 6 mm, increase it to around 9 mm.
   • This is a reference value and should be adjusted based on actual equipment conditions.
3. Ensure that the Hex Wrench Bolt is tightened sufficiently to prevent loosening during operation.

Step 3: Reinstall the Suction Unit

1. Reinstall the Suction Unit into the AFU.
2. During Ballasting, monitor the Auto Backflushing process.
3. Check if the AFU's Differential Pressure (DP) value decreases properly.

📌 Why?
This adjustment ensures that the Teflon Nozzle makes better contact with the Filter Element, improving Backflushing performance.

5. Summary of Key Actions