Aqua-Nautica Energy Recovery Watermaker – Initial Start-Up and Recommissioning After Winterization

1. Why Is the System Shipped with Propylene Glycol?

All Aqua-Nautica watermakers are shipped in a winterized condition using propylene glycol. This protects the membranes from bacterial growth during storage and prevents freeze damage during transportation and winter conditions.

Before operating the system for the first time, or after winter storage, the propylene glycol must be completely flushed out of the system.

2. First Check: Open the Dump Valve

The most important step before starting the system is to ensure that the triangular dump valve located on the Clark Pump assembly is open.

Open the valve by turning it counterclockwise approximately 1–2 turns.

At this stage, the product water line must be directed overboard and not into the freshwater tank.

Failure to open the dump valve may cause propylene glycol to be forced into the membranes. This can lead to membrane fouling and blockage. Although the problem can usually be corrected, it may require a lengthy cleaning procedure and, in some cases, can result in permanent membrane damage.

3. Filling the System with Fresh Water

After confirming that all plumbing connections are completed and the dump valve is open, press the Flush button.

The Flush function opens the solenoid valve located after the carbon filter on the freshwater supply line from the boat's water tank.

When the solenoid valve opens, the boat's pressure water pump will detect the pressure drop and automatically start running.

Fresh water from the tank will then fill the entire system. A check valve installed in the seawater intake circuit prevents water from flowing back overboard, allowing the complete system to fill with fresh water.

Holding the Flush button for approximately 1–2 minutes is generally sufficient.

4. Initial Seawater Flush Without Pressure

After the fresh water filling process is completed, stop the Flush function and press the Start button.

The system should now run with seawater for at least 30–40 minutes without building high pressure.

This flushing process removes most of the propylene glycol remaining inside the system.

Do not perform this procedure in polluted water. Marinas, city harbors, industrial areas, or locations where oil, diesel fuel, or other contaminants may be present are unsuitable.

Operating in contaminated water can cause irreversible membrane damage even before the system has been properly commissioned.

5. Pressure Adjustment and Initial Water Production

Once the seawater flushing process has been completed, gradually close the pressure regulating valve.

Adjust the system so that operating pressure does not exceed 60 bar (870 psi).

The final pressure adjustment is made using the bypass valve located on the stainless-steel high-pressure pump assembly.

The initial product water must be discharged overboard for at least one hour.

This ensures that any remaining propylene glycol and any residual chemicals from the membrane manufacturing process are completely removed from the system.

6. Testing Product Water Quality

After the initial production period, collect a sample of product water and test it using a conductivity or TDS meter.

The actual water production rate should also be verified.

Using a 0.5-liter, 1-liter, or 1.5-liter measuring container, record the time required to fill the container.

The actual production rate can be calculated using the following formula:

Production Rate (L/h) = Container Volume (L) ÷ Filling Time (seconds) × 3600

Example

If a 1-liter container fills in 60 seconds:

1 ÷ 60 × 3600 = 60 liters per hour

This calculation provides the actual production capacity of your watermaker under current operating conditions.

7. Ready for Normal Operation

Once the conductivity reading is within specification and the production rate has been verified, the product water line can be redirected to the freshwater tank.

The system is now fully commissioned and ready for normal operation.

Quick Summary

Before putting your Aqua-Nautica watermaker into service:

• Ensure the Clark Pump dump valve is open.
• Direct initial product water overboard, not into the tank.
• Fill the system with fresh water using the Flush function.
• Flush with seawater for at least 30–40 minutes without pressure.
• Avoid polluted or contaminated water during commissioning.
• Discharge product water overboard for at least one hour.
• Verify water quality using a conductivity or TDS meter.
• Measure and confirm actual production capacity.

Following these simple steps will help protect your membranes, ensure optimum water quality, and maximize the service life of your Aqua-Nautica watermaker.