METxxMB

Common issues

• Bearing wear (radial and thrust bearings) leading to increased rotor clearances and vibration.
• Fouling of compressor wheel and diffuser due to airborne contaminants, reducing efficiency.
• Fouling or erosion of turbine blades and nozzle ring due to exhaust gas quality, affecting performance and potentially causing imbalance.
• Oil leakage from bearing seals or casing joints, posing fire hazards and indicating seal wear.
• Exhaust gas leakage from turbine casing joints or expansion bellows, indicating seal/gasket failure or cracking.
• Corrosion on compressor casing components, especially in high-humidity or salty environments.
• Malfunction of speed sensor or associated electronic control components due to vibration, moisture, or age.
• Foreign object damage (FOD) to compressor or turbine blades, causing imbalance and potential catastrophic failure.

Inspection checklist

• Observe turbocharger for abnormal noise, vibration, or surging during operation.
• Visually inspect for any oil, exhaust gas, or cooling water leaks from casing joints, seals, and associated piping.
• Check bearing temperatures (if sensors fitted) and lubricating oil pressure (if separate system) against manufacturer's limits.
• Inspect the air filter element for cleanliness, damage, and proper seating.
• Verify rotor axial and radial clearances (static check, engine stopped and cool) against wear limits using a dial gauge.
• Inspect compressor wheel and diffuser for fouling, erosion, or foreign object damage (FOD) via inspection ports or by opening the casing.
• Inspect turbine blades and nozzle ring for fouling, erosion, cracks, or FOD via inspection ports or by opening the casing.
• Check the condition of flexible bellows/expansion joints on the exhaust gas inlet and outlet for cracks or leaks.
• Verify functionality of the speed sensor and associated alarm/shutdown systems by checking readings and alarm setpoints.
• Inspect all casing bolts, foundation bolts, and anti-vibration mounts for tightness, corrosion, and integrity.

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 set of main bearings (radial and thrust bearings).
• Full set of O-rings and gaskets for casing and oil/air seals.
• Turbocharger speed sensor.
• Air filter element(s).
• Lubricating oil filter elements (if separate lubrication system).
• Balancing weights for rotor re-balancing.
• Emergency repair kit for minor casing damage (e.g., high-temperature sealant, specific fasteners).

Safety

• High Surface Temperatures: Casing and exhaust piping operate at very high temperatures (up to 400-500°C), posing severe burn risks. Ensure insulation is intact and guarding is in place.
• High Rotational Speed & Potential for Disintegration: The rotor operates at extremely high RPMs (e.g., 10,000-20,000+ RPM). Catastrophic failure due to imbalance, bearing seizure, or FOD can lead to disintegration, projecting fragments at high velocity.
• Noise Hazard: High noise levels during operation require mandatory hearing protection in the vicinity of the turbocharger.
• Hot Exhaust Gas/Oil Leaks: Leaks from casing joints or oil lines can cause severe burns, fire hazards, and create slippery surfaces.
• Pressurized Systems: Intake air and exhaust gas are under pressure; ensure proper depressurization procedures are followed before opening any part of the turbocharger or its associated piping.

Class survey

During annual Class Survey, the surveyor will typically check the overall external condition, cleanliness, and integrity of the turbocharger, including insulation and guarding. They will verify maintenance records, service reports, and logbook entries to ensure compliance with manufacturer's service schedule and Class requirements. Functionality of safety devices (e.g., overspeed trip, alarm systems) and availability of critical spare parts will be confirmed. If the turbocharger is opened for maintenance during the survey period, the surveyor may witness rotor clearance measurements and internal component inspections. Any reported defects or repairs will be reviewed.