TCT

Common issues

• Nozzle ring fouling (leading to reduced efficiency, increased exhaust gas temperatures, and potential turbocharger surging)
• Compressor fouling (impacting air delivery, reducing engine power, and potentially causing compressor surge)
• Bearing wear (both journal and thrust bearings, indicated by increased axial/radial clearances, high bearing temperatures, or oil contamination)
• Rotor imbalance (often caused by uneven fouling, blade damage, or bearing wear, leading to excessive vibration)
• Turbine blade erosion or foreign object damage (FOD) (reducing efficiency and potentially leading to rotor imbalance)
• Compressor wheel erosion or FOD (impacting air flow, efficiency, and potentially leading to surge or imbalance)
• Oil leakage from bearing housing seals or casing joints
• Exhaust gas leakage from turbine casing joints, expansion bellows, or drain points

Inspection checklist

• Visual inspection of compressor and turbine sides for fouling, erosion, cracks, or foreign object damage (FOD) on blades, nozzle ring, and diffuser
• Check rotor axial and radial clearances (float) against manufacturer's specified limits using a dial gauge; look for excessive play
• Inspect bearing condition: check for signs of wear, discoloration, proper lubrication, and any oil leaks from the bearing housing
• Verify integrity of all casings (turbine, compressor, bearing housing) for cracks, exhaust gas or oil leaks, and ensure all bolts are secure
• Check air inlet filter condition and ensure proper sealing to prevent unfiltered air ingress
• Inspect exhaust gas and compressor wash drains for blockage and ensure proper functionality
• Monitor turbocharger vibration levels (if equipped with sensors) and compare to baseline and alarm limits
• Check lubricating oil pressure and temperature at inlet/outlet, and inspect oil quality for signs of contamination or degradation
• Confirm security of all mounting bolts, air ducts, exhaust pipes, and oil/water connections

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 and pads)
• O-rings and gaskets for casing joints, inspection covers, and oil/air seals
• Air inlet filter elements (if applicable to the specific installation)
• Nozzle ring segments (if modular design) or a complete nozzle ring
• Sealing rings (e.g., labyrinth seals for compressor and turbine sides)
• Lubricating oil filter elements (if the turbocharger has a dedicated oil system or filter)
• High-temperature bolts and nuts for turbine casing and exhaust connections

Safety

• High rotational speeds (up to 20,000 RPM for large units) – potential for catastrophic uncontained failure if rotor integrity is compromised
• Extremely high temperatures (exhaust gas up to 550°C, casing surfaces) – severe burn hazard; ensure proper insulation and warning signs
• High pressure compressed air (up to 5 bar gauge) – risk of injury from sudden release or hose/pipe failure during operation or maintenance
• Hot lubricating oil under pressure – burn and slip hazard during inspection or maintenance
• Stored energy in casing bolts – proper sequence and torque values must be strictly followed during assembly/disassembly to prevent injury or damage

Class survey

Class surveyors will typically conduct an annual visual inspection of the turbocharger for external damage, leaks, and security of mounting. They will review the vessel's maintenance records, including cleaning logs, bearing replacements, and overhaul reports, ensuring compliance with PBST's service instructions and classification society rules. Functionality of safety devices such as overspeed trip and alarm systems will be verified. Surveyors will also check for excessive vibration, abnormal exhaust gas temperatures, and overall operational stability. Availability of critical spare parts as per Class requirements (e.g., IACS Unified Requirements M42) will be confirmed.