1. Overview

The BFP (Back Flushing Pump) is located near the AFU (Auto Filter Unit), and a 3-way valve is installed beneath the gauge of the BFP.

2. 3-Way Valve Adjustment

• The OFF direction of the 3-way valve should always point toward the Air Vent.
  
• If the ON direction is set toward the Air Vent, seawater leakage may occur.

3. Plastic Washer Replacement

1. Ensure the OFF direction of the 3-way valve is set toward the Air Vent.
2. Remove the Air Vent Plug to replace the Plastic Washer.
3. When reinstalling the Air Vent Plug:
   • Do not overtighten; it should be secured just enough to prevent loosening.
   • Over-tightening may damage the Plastic Washer.
4. Purpose of the Air Vent Plug:
   • Used for gauge testing.
   • Functions as an air vent.

4. Normal Operating Condition

• Even when the BFP is running normally, the OFF direction of the 3-way valve must always point toward the Air Vent.