A180-L 180-L37

Common issues

• Bearing wear (journal and thrust bearings) due to lubrication issues, contamination, or extended service intervals, leading to increased clearances and vibration.
• Compressor fouling (impeller and diffuser) from intake air contamination or oil carry-over from the sealing air system, resulting in reduced air flow and boost pressure.
• Turbine fouling and erosion (nozzle ring and turbine blades) caused by poor fuel combustion, high exhaust gas temperatures, or catalytic fines in HFO, leading to reduced efficiency and potential imbalance.
• Oil leakage from bearing housing seals (labyrinth or mechanical) into the compressor or turbine side, or externally, indicating seal wear or incorrect sealing air pressure.
• Rotor imbalance due to uneven fouling, blade damage, or bearing wear, manifesting as excessive vibration and noise.
• Cracks in turbine or compressor casings, often due to thermal stress cycles or external impact, compromising structural integrity and gas tightness.
• Sealing air system malfunction (low pressure, blocked lines) leading to oil ingress into gas paths or external leakage.

Inspection checklist

• Check turbocharger bearing temperatures (local gauges and alarm logs) for any abnormal readings or trends.
• Verify lubricating oil inlet pressure and temperature, and outlet temperature, ensuring they are within manufacturer's specified limits.
• Inspect sealing air pressure and flow, ensuring adequate differential pressure to prevent oil migration.
• Visually inspect compressor impeller and diffuser for fouling, erosion, or damage through the air intake filter opening.
• Visually inspect turbine blades and nozzle ring for fouling, erosion, or foreign object damage (FOD) through the exhaust gas outlet or inspection ports.
• Check for any oil leaks around the bearing housing, oil supply/drain lines, and external casing joints.
• Listen for unusual noises (whining, grinding, rubbing) or feel for excessive vibration using a vibration pen or hand test.
• Inspect air filter elements for cleanliness and differential pressure across the filter.
• Check all mounting bolts and connections for tightness, and inspect insulation for integrity.
• Measure axial and radial clearances (during scheduled overhauls) to assess bearing wear.

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 assembly (journal and thrust bearings) with associated seals and O-rings.
• Gasket and O-ring set for major overhaul.
• Oil filter elements (if applicable to the specific lubrication system).
• Sealing air labyrinth seals (if not part of bearing assembly).
• Impeller nut and locking washer.
• Nozzle ring segments (if modular design) or a complete nozzle ring.
• Set of turbine blades (if replaceable, often part of rotor assembly for this size).
• Temperature sensors and pressure transducers (common failure items).

Safety

• High-speed rotating machinery: Risk of catastrophic failure (disintegration) if bearings fail or severe imbalance occurs, leading to projectile hazards.
• High temperatures: Exhaust gas casing and turbine components operate at very high temperatures, posing severe burn risks. Ensure insulation integrity.
• High pressures: Compressor discharge air and exhaust gas are under pressure; sudden release can cause injury.
• Noise: Turbochargers generate significant noise levels; hearing protection is mandatory in the vicinity.
• Oil mist/leakage: Potential fire hazard if oil leaks onto hot surfaces, and slip hazard on deck plates.

Class survey

A class surveyor will typically check the general condition and cleanliness of the turbocharger, looking for any signs of oil leakage, excessive corrosion, or physical damage to the casings and insulation. They will review maintenance records, including bearing replacement dates, overhaul history, and records of compressor/turbine washing. Operational parameters such as bearing temperatures, lubricating oil pressures, and boost pressure trends will be scrutinized. The surveyor will also verify the integrity of mounting arrangements, exhaust gas trunking, and safety devices like overspeed trip mechanisms (if applicable to the specific engine/TC configuration, though less common for TC itself). Evidence of proper sealing air system operation and the condition of air intake filters are also key points.

Estimated lifetime: 48,000 hours (before major overhaul and potential component renewal of rotor assembly, casings can last much longer with proper maintenance)