A185-L 185-L32

Common issues

• Fouling of compressor impeller and diffuser, leading to reduced efficiency and surging.
• Fouling of turbine nozzle ring and blades, causing increased exhaust gas back pressure and reduced power output, especially with HFO operation.
• Wear or failure of journal and thrust bearings, indicated by increased vibration, abnormal noise, or high bearing temperatures.
• Oil leakage from bearing housing seals (labyrinth seals), often due to wear, incorrect clearances, or issues with sealing air pressure.
• Cracks in turbine casing, nozzle ring, or exhaust gas manifold connections due to thermal stress and fatigue.
• Turbocharger surging, which can be caused by engine issues, severe fouling, or damage to compressor/turbine components.
• Exhaust gas leakage from casing joints, leading to power loss and potential fire hazard.
• Malfunction of water washing system (clogged nozzles, insufficient pressure) leading to ineffective cleaning and rapid fouling.

Inspection checklist

• Check for any oil or exhaust gas leaks around the turbocharger casing, piping, and connections.
• Visually inspect compressor and turbine sides (via inspection ports) for fouling, damage, or foreign object ingress.
• Monitor bearing oil pressure and temperature, ensuring they are within manufacturer's specified limits.
• Check turbocharger rotational speed, exhaust gas temperatures (inlet/outlet), and scavenging air pressure for deviations from normal operating parameters.
• Listen for abnormal noises (whining, rubbing, knocking) and check for excessive vibration using portable vibration analysis equipment.
• Inspect the condition of the air filter elements and ensure the compressor inlet is clean and unobstructed.
• Verify the functionality and integrity of the water washing system, including nozzle condition and drain lines.
• Check security of all mounting bolts, insulation covers, and safety guards.
• Inspect the lubricating oil system for the turbocharger, including oil level, quality, and any signs of contamination.

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Complete bearing cartridge assembly (journal and thrust bearings)
• Set of sealing rings (labyrinth seals) for both compressor and turbine sides
• Gasket and O-ring kit for casing joints and inspection covers
• Air filter elements (if applicable to the specific intake arrangement)
• Water washing nozzles and associated seals
• Nozzle ring segments (if design allows for segment replacement, otherwise a full nozzle ring)
• Lubricating oil pump (if external and critical for operation)

Safety

• High surface temperatures of the exhaust gas casing (can exceed 300°C), posing severe burn risks. Ensure insulation is intact.
• Extremely high rotational speeds (up to 15,000-20,000 RPM for this size), with potential for rotor burst if overspeed or severe imbalance occurs. Overspeed trip must be functional.
• High noise levels requiring hearing protection in the vicinity during operation.
• Pressurized systems (exhaust gas, scavenging air, lubricating oil) can cause injury if components fail or are improperly handled.
• Handling of heavy components during maintenance (rotor, casings) requires proper lifting gear and procedures to prevent crushing injuries.

Class survey

Class surveyors will typically review the vessel's Planned Maintenance System (PMS) records for the turbocharger, including service reports, bearing replacements, and cleaning logs. They will visually inspect the turbocharger for external leaks (oil, exhaust gas), cracks, and secure mounting. Operational parameters (bearing temperatures, oil pressure, turbocharger RPM, exhaust gas temperatures) will be checked against normal values. The functionality of the overspeed trip device is a critical check, often witnessed during specific tests or sea trials. General condition of insulation, safety guards, and accessibility for maintenance will also be assessed to ensure compliance with safety and operational standards.

Estimated lifetime: The main casing and rotor shaft can exceed 100,000 running hours with proper maintenance. Major overhaul (bearings, seals, cleaning, minor component replacement) is typically performed between 24,000 to 48,000 hours.