1. Overview

This guide outlines key precautions when performing Ballasting or Deballasting via bypass (either in Bypass Mode or Maintenance Mode).
Since AFU (Auto Filter Unit) is bypassed, debris may enter piping and tubing, potentially causing blockages or damage.

To prevent system failures, follow these precautions:

2. Key Precautions for Bypass Operation

Step 1: Close TIP and TOP Valves

• Why? If debris clogs the SUS tubing connected to the TRO Sensor Unit (TSU), the TRO measurement will fail, leading to a system shutdown.
• Action:
  • Before enabling bypass, completely close the TIP and TOP valves.
  • These valves are installed on the main piping and connect to the lower part of the TSU via SUS tubing.

📌 TIP & TOP Valves Location:
Located on the main pipeline and connected via SUS tubing to the TSU (TRO Sensor Unit).

Step 2: Close the EIP Valve (In case of branching from the main pipe)

• Why? If debris enters through the EIP valve, it can damage the ECU Booster Pump (EBP).
• Action:
  • Close the EIP valve before operating in bypass.
  • The EIP valve is installed on the main pipeline and connects to the EBP inlet.

📌 EIP Valve Location:
Installed on the main piping, connected to the EBP inlet.

3. Additional Precautions

1. Compliance with Ballast Water Management Plan (BWMP):

   • When performing Ballasting/Deballasting via bypass, follow D-1 operation procedures.
   • Report to the Flag State and log the operation in the Ballast Water Record Book (BWRB).

2. Returning to Normal System Operation:

   • If operating via BALLAST or DEBALLAST screen (not bypass) normally, fully open the TIP, TOP, and EIP valves.