System Description:

• The main CO₂ bottles store CO₂ in liquid form at a pressure of 56 bar at 20°C and 64 bar at 25°C. Therefore, the CO₂ room temperature must be kept low to prevent excessive pressure buildup.
• The release mechanism is housed in the CO₂ release cabinet. Opening this cabinet triggers both an audible and visual alarm in the machinery space.
• Additionally, opening the cabinet sends a signal to the electronic control system, which automatically shuts all engine room ventilation dampers and quick-closing valves (QCVs).

Release Mechanism:

• The CO₂ release cabinet contains two pilot bottles filled with CO₂.
• To initiate release:
  1. Locking pins on the pilot bottles are removed.
  2. Valve 1 (V/V 1) is opened, activating the master valve.
  3. Valve 2 (V/V 2) is opened, which actuates the bottle head assemblies of the main CO₂ bottles.
• This sequential operation releases CO₂ from the main bottles into the common manifold.
• Each main CO₂ bottle is fitted with a non-return valve (NRV) to ensure unidirectional flow.
• CO₂ is then delivered through distribution lines and nozzles into the machinery space.

Discharge Requirements:

• A minimum of 50% of the total CO₂ quantity must be discharged within 1 minute, and at least 85% must be fully released within 2 minutes.
• This rapid discharge is achieved by using dip tubes, which allow the liquid phase of CO₂ to be released efficiently.

• Conduct a headcount to ensure no personnel are inside the machinery space.
• Ensure that audible and visual alarms are activated in the engine room.
• Confirm that the main master valve or distribution valve is opened before the pilot valve.
• Allow sufficient time for escape to any personnel potentially in the space before the CO₂ is released.

Reason for Securing:

• CO₂ bottles must be secured properly to prevent movement due to vibration or during emergency conditions.
• Loose bottles may cause damage to the piping system, affect discharge sequence, or pose a safety hazard.

Checks Carried Out:

• Verify that each bottle is firmly clamped using secure mounting brackets or restraining bands.
• Inspect the securing arrangements during routine maintenance and drills.
• Ensure proper alignment of bottles to maintain smooth operation of the release mechanism and avoid mechanical obstruction.
• Confirm no physical damage or corrosion at securing points.
• Check that securing does not interfere with access to valves or identification markings.