A100-M 100-M52

Common issues

• Bearing wear and failure (journal and thrust bearings) due to lubrication issues, contamination, or excessive vibration.
• Compressor wheel fouling or erosion, leading to reduced efficiency and surging, often caused by dirty intake air or moisture.
• Turbine wheel and nozzle ring fouling or erosion, particularly when operating on heavy fuel oil (HFO) with high ash content, leading to reduced performance and increased exhaust back pressure.
• Oil leakage from bearing casing seals (e.g., labyrinth seals, piston ring seals) into the compressor or turbine side, indicating seal wear or pressure imbalances.
• Rotor imbalance, often caused by blade damage, fouling, or bearing wear, leading to excessive vibration and potential catastrophic failure.
• Cracks in the exhaust gas casing due to thermal stresses, especially around mounting points or expansion joints.
• Turbocharger surging, often a symptom of compressor fouling, engine load changes, or issues with the engine's air supply/exhaust system.

Inspection checklist

• Check for oil leaks from the bearing casing and exhaust gas leaks from the turbine casing, connections, and drains.
• Verify bearing temperatures (if monitored) are within manufacturer's specified limits (typically < 90°C).
• Inspect the compressor wheel for fouling, erosion, or foreign object damage (FOD) through the air intake, ensuring blades are clean and intact.
• Inspect the turbine wheel and nozzle ring for fouling, erosion, or damage through the exhaust outlet (if accessible), looking for deposits, cracks, or bent blades.
• Check axial and radial clearances of the rotor (requires opening the casing during scheduled maintenance or if issues are suspected) against manufacturer's limits.
• Verify the security of all mounting bolts, support structures, and pipe connections to the turbocharger.
• Check the condition of air filter elements and, if applicable, the turbocharger's dedicated oil filter elements.
• Listen for unusual noises (e.g., grinding, rubbing, whistling) or excessive vibration during operation.
• Review operational parameters: boost pressure, exhaust gas temperatures before and after the turbine, and turbocharger RPM, comparing to design values and historical trends.

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 (including sleeves/bushes if applicable).
• Oil sealing rings/gaskets (e.g., labyrinth seals, piston rings) for both compressor and turbine sides.
• Full gasket and O-ring set for casing overhaul.
• Air filter elements (if applicable to the turbocharger's intake system).
• Nozzle ring (or segments, depending on design) and diffuser.
• Mounting bolts and locking washers.

Safety

• Extremely high surface temperatures of the exhaust gas casing (can exceed 400°C), posing severe burn hazards. Ensure insulation is intact.
• High rotational speeds (up to 50,000 RPM for this frame size), carrying a risk of rotor burst if severely damaged or imbalanced, leading to projectile hazards.
• Pressurized air (up to 5 bar) and oil systems (up to 3 bar), with potential for high-velocity spray from leaks, posing fire and injury risks.
• High noise levels during operation (typically >100 dB), requiring hearing protection in the vicinity.
• Potential for hot oil spray from leaks onto hot surfaces, creating a significant fire hazard.

Class survey

Class surveyors typically focus on the integrity and operational safety of the turbocharger. This includes reviewing maintenance logbook entries for dates of last overhaul, bearing replacements, and cleaning. They will verify operational parameters (boost pressure, exhaust temperatures, TC RPM) against manufacturer's specifications and historical data. A visual inspection for any signs of oil or exhaust gas leakage from casings, connections, and drains is crucial. The integrity of insulation on hot parts and the security of mounting bolts will be checked. Confirmation of proper functioning of safety devices (e.g., overspeed trip, low oil pressure alarm if applicable) and the general condition of the air intake filter and exhaust gas outlet are also key points.

Estimated lifetime: 100,000 - 150,000 hours before major component replacement (e.g., rotor shaft, casings) with diligent maintenance and adherence to service schedules.