METxxSEII

Common issues

• Excessive wear of journal and thrust bearings, leading to increased rotor play and vibration.
• Fouling and/or erosion of compressor wheel and diffuser, reducing air flow and overall efficiency.
• Fouling and/or erosion of turbine blades and nozzle ring, increasing exhaust back pressure and decreasing power output.
• Oil leakage from bearing housing seals, resulting in increased lube oil consumption and potential for oil ingress into exhaust or charge air.
• Vibration due to rotor imbalance, bearing wear, or foreign object damage (FOD) to blades.
• Cracks or deformation in turbine or compressor casings due to thermal stress or mechanical impact.
• Malfunction of water washing system (if fitted) leading to rapid fouling accumulation.
• Corrosion of external surfaces and fasteners due to saltwater/salt-laden air exposure.

Inspection checklist

• Measure and record axial and radial play of the rotor shaft (critical measurement).
• Visually inspect compressor wheel and diffuser for fouling, erosion, or foreign object damage (FOD).
• Visually inspect turbine blades and nozzle ring for fouling, erosion, cracks, or rubbing marks (requires borescope or casing opening).
• Check for any signs of oil leakage around the bearing housing, oil supply/drain lines, and casing joints.
• Monitor and log operational parameters: exhaust gas temperatures (before/after turbine), boost pressure, lube oil pressure/temperature, and vibration levels.
• Listen for unusual noises (e.g., rubbing, whistling, grinding) during operation.
• Inspect all casing components for cracks, loose bolts, signs of exhaust gas leakage, or corrosion.
• Verify the condition and cleanliness of the air filter elements and charge air cooler.
• Check functionality of the water washing system (if installed) and ensure nozzles are clear.

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 journal and thrust bearings.
• Oil seals and O-rings for bearing housing.
• Gasket set for turbine and compressor casings, and connections.
• High-temperature bolts and nuts for casing connections.
• Lube oil filter elements (if external filter is part of the turbocharger system).
• Complete rotor cartridge assembly (highly recommended for rapid repair, though a significant investment).

Safety

• **High Temperatures**: Exhaust gas and casing surfaces operate at extremely high temperatures, posing severe burn risks. Always ensure proper cooling down time or use appropriate PPE.
• **Rotating Machinery**: The rotor operates at very high speeds. Accidental contact during operation or uncontained failure can cause severe injury or fatality.
• **High Pressure**: Compressor discharge air is under high pressure. Improper handling of connections or casing integrity failure can lead to explosive decompression.
• **Uncontained Failure**: Catastrophic failure of the rotor (e.g., due to overspeed or material fatigue) can release high-energy fragments, posing extreme danger to personnel and machinery.
• **Exhaust Gas Leaks**: Leaks from the turbine casing or exhaust ducts can lead to toxic atmosphere in machinery spaces (CO, NOx) and reduced engine performance.

Class survey

During annual or special surveys (DNV TA certificate TAM0000154), the class surveyor will typically verify adherence to manufacturer's maintenance schedule and classification society requirements. This includes reviewing logbook entries for operational parameters (exhaust gas temperatures, boost pressure, lube oil data, vibration), visual inspection for oil/gas leaks, casing integrity, and general condition. Records of bearing axial/radial play measurements are critical. If the turbocharger is opened for maintenance, the surveyor may inspect the condition of the rotor, blades, and nozzle ring. Verification of critical spare parts onboard is also common.