Fuel Oil Purifier

The correct start-up procedure of a fuel oil purifier is essential to ensure safe operation, proper separation efficiency, and long service life of the machine.
Improper starting may cause oil loss, poor separation, bowl vibration, or even mechanical damage.
Every marine engineer must follow a systematic procedure before introducing fuel into the purifier.

The following step-by-step guide explains the standard onboard practice used in modern self-cleaning marine fuel oil purifiers.

Pre-Start Safety Checks

• Confirm lube oil level in the gear case.
• Open fresh water supply for sealing and operating water.
• Check heater and steam supply availability.
• Verify discharge lines to sludge tank and service tank are clear.
• Ensure no valves are closed.

Step-by-Step Fuel Oil Purifier Start-Up Procedure

Step 1 – Start Feed Pump and Heater

Start the fuel oil feed pump and heater first. Heat the fuel to the recommended temperature, normally between 98°C and 104°C.
Heating reduces viscosity and improves centrifugal separation efficiency.

Step 2 – Start Purifier Motor

Switch ON the purifier motor and allow the bowl to accelerate gradually.
Do not introduce oil immediately. Let the purifier reach full rated speed.

Normally full speed is around 7,000–9,000 RPM depending on the model.

Step 3 – Closing (Operating) Water (manual)

Supply operating water to the hydraulic chamber through the pilot valve.
This pressure lifts the sliding bowl bottom upward and locks the bowl tightly in the closed position.

Without proper closure, oil leakage and loss of separation will occur.

Step 4 –Sealing Water (manual)

Introduce sealing water into the bowl to form the water ring at the periphery.
This creates the oil-water interface necessary for two-phase separation.

Sealing water must be clean fresh water to avoid scaling or corrosion.

Step 5 – Check for Abnormalities

• No vibration
• No unusual noise
• No leakage
• Stable current draw

Step 6 – Slowly Introduce Fuel Oil

Gradually open the fuel inlet valve and allow oil to enter slowly.
Sudden introduction may disturb the interface and cause mixing.

Observe discharge pressure gauge to confirm:

• Clean oil flowing through oil outlet
• Water discharge through water outlet
• No oil loss through water line 

Step 7 – Monitor Initial Operation

During the first 10–15 minutes, continuously monitor:

• Temperature
• Pressure
• Vibration
• Discharge pressure 
• Amperage

Stable readings indicate successful start-up.

Step 8 – Set Automatic Desludging

Once separation stabilizes, activate automatic desludging timer.
The pilot valve will periodically release operating water to discharge sludge automatically.

Common Start-Up Mistakes to Avoid

• Feeding oil before full speed
• No sealing water
• Cold oil supply
• Wrong gravity disc
• Sudden high flow rate

Frequently Asked Questions

Why must the purifier reach full speed before oil entry?

Full centrifugal force is required for separation. Feeding oil early causes mixing and sludge carryover.

Why is sealing water added before oil?

To create the interface and prevent oil loss through the water outlet.

What happens if operating water fails?

The bowl may not close properly, resulting in leakage or poor purification.

Related Topics

• Fuel Oil Purifier System – Definition, Purpose, and Operation Explained
• Fuel Oil Purifier Principle – Separation Process Explained
• Function of Paring Disc in Purifier – Working Principle and Purpose
• Purpose of Sealing Water in Fuel Oil Purifier Operation
• Closing Water in Purifier – Hydraulic Operation in Self-Cleaning Bowls
• Pilot Valve in Purifier – Hydraulic Distributor Function Explained
• Self-Cleaning Purifier Bowl Components – Parts and Functions Explained

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