TPL-B 85-B12

Common issues

• Bearing wear (thrust and journal bearings) leading to increased axial/radial play and potential rotor contact.
• Compressor fouling (dirt, oil mist) reducing efficiency and air delivery, potentially causing surging.
• Turbine fouling (soot, unburnt fuel) reducing efficiency, increasing exhaust back pressure, and causing thermal stress.
• Nozzle ring and/or cover ring erosion/corrosion/cracking, impacting turbine efficiency and gas flow.
• Oil leakage from bearing housing seals (labyrinth seals) into the compressor or turbine side, indicating seal wear or incorrect oil pressure.
• Rotor imbalance due to fouling, blade damage, or bearing wear, leading to excessive vibration.
• Surging, particularly at low loads or during rapid load changes, causing high stress on rotor and bearings.
• Exhaust gas casing cracks or hot spots due to thermal cycling or material fatigue.

Inspection checklist

• Check axial and radial play of the rotor shaft. Compare with manufacturer's limits (e.g., new axial play ~0.15-0.35mm, wear limit ~0.5-0.7mm; new radial play ~0.2-0.4mm, wear limit ~0.6-0.8mm).
• Inspect compressor wheel for fouling, erosion, foreign object damage (FOD), and cracks, especially at blade roots and leading edges.
• Inspect turbine wheel and blades for fouling, erosion, burning, and cracks. Check for signs of contact with the casing.
• Examine nozzle ring and cover ring for erosion, cracks, deformation, and carbon deposits. Ensure free movement of variable nozzle vanes if applicable.
• Check oil inlet and drain lines for leaks, proper flow, and pressure. Verify oil temperature and pressure are within specified limits.
• Inspect air filter elements for cleanliness and damage. Ensure proper sealing of the filter housing.
• Verify functionality of water washing systems (compressor and turbine) and ensure nozzles are clear.
• Monitor turbocharger vibration levels (if equipped with sensors) and listen for unusual noises during operation.
• Inspect exhaust gas casings for cracks, hot spots, insulation integrity, and proper securing.

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 bearings (thrust and journal bearings) and associated seals/O-rings.
• Gasket and O-ring sets for bearing casing and gas/air casings.
• Air filter elements (if non-washable type).
• Nozzle ring segments or complete nozzle ring (depending on design and maintenance strategy).
• Oil pump (if external, for lubrication system).
• Overspeed trip bolt/mechanism (if mechanical type).

Safety

• High-speed rotating machinery: Risk of catastrophic failure (disintegration) if overspeed or severe imbalance occurs. Always ensure overspeed trip is functional.
• Hot surfaces: Exhaust gas casings and turbine side components operate at extremely high temperatures (300-600°C). Risk of severe burns. Ensure proper insulation and warning signs.
• High-pressure exhaust gas and compressed air: Risk of injury from sudden release or leakage. Always depressurize systems before opening.
• Oil mist and leakage: Potential fire hazard, especially in hot engine room environments. Ensure oil lines are secure and free from leaks.
• Noise levels: Turbochargers generate significant noise. Hearing protection is mandatory when working near an operating unit.

Class survey

Class surveyors will typically review the turbocharger's maintenance records, including bearing replacements, overhauls, and cleaning logs. They will check for external signs of oil or exhaust gas leakage, excessive vibration, and proper securing. Operational parameters (exhaust gas temperatures, air pressure, turbocharger speed) will be checked against design values. The functionality of the overspeed trip device and any associated alarms will be verified. Compliance with manufacturer's recommendations for service and any outstanding service bulletins will also be scrutinized. For larger units like the TPL-B 85-B12, the condition of the exhaust gas casing, insulation, and expansion joints is also a key focus.

Estimated lifetime: 16,000 - 24,000 running hours before major overhaul (rotor out), with component replacement extending total unit life to 20-30 years.