SR 66SR

Common issues

• Bearing wear (journal and thrust bearings), leading to increased clearances and vibration.
• Fouling of compressor wheel and diffuser, reducing air flow and efficiency, especially in humid or dusty environments.
• Fouling and erosion of turbine blades and nozzle ring due to combustion byproducts (soot, vanadium, sulfur), leading to reduced efficiency and potential damage.
• Exhaust gas leakage from casing joints, gland seals, or expansion bellows, causing power loss and safety hazards.
• Lubricating oil system issues: low pressure, high temperature, or contamination, directly impacting bearing life.
• Rotor imbalance due to material deposition or erosion, leading to excessive vibration and potential catastrophic failure.
• Surging, often caused by engine operating conditions (low load, rapid load changes) or compressor fouling, leading to mechanical stress.
• Water washing system malfunction (clogged nozzles, insufficient pressure), hindering effective cleaning and accelerating fouling.

Inspection checklist

• Visual inspection for oil, gas, or water leaks from casing joints, drain lines, and gland seals.
• Check bearing temperatures (local gauges or remote monitoring) for abnormal readings; typical operating range 60-85°C.
• Monitor lubricating oil pressure and flow to bearings; ensure within manufacturer's specified range (e.g., 1.5-3.0 bar at inlet).
• Inspect air filter condition (if fitted) and ensure clean air supply to compressor inlet.
• Check compressor and turbine side cleanliness via inspection ports; assess fouling levels and schedule water washing if necessary.
• Verify security of mounting bolts and anti-vibration mounts; check for signs of fretting or loose connections.
• Listen for abnormal noises (whining, grinding, rubbing) indicating bearing damage or rotor contact.
• Check exhaust gas and charge air pressure/temperature readings against engine load and manufacturer's data for performance deviations.
• Inspect water washing system components (nozzles, drains) for blockages or damage.
• Verify functionality of overspeed trip device (if testable during operation) and associated alarms.

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 cartridges (journal and thrust bearings) - typically one set.
• Gland seals (air and oil side) and associated O-rings/gaskets.
• Nozzle ring segments (if modular design) or a complete nozzle ring.
• Set of all critical O-rings and gaskets for casing joints and inspection covers.
• Lubricating oil filter elements (if separate from engine system).
• Water washing nozzles and associated fittings.
• High-speed balancing kit (if authorized and trained personnel are onboard, otherwise for shore service).

Safety

• High temperatures: Exhaust gas casing and associated piping can reach 300-500°C, posing severe burn risks. Ensure adequate insulation and warning signs.
• High rotational speeds: Rotor operates at tens of thousands of RPM. Catastrophic rotor failure (burst) due to imbalance or material fatigue can cause severe damage and injury. Always adhere to maintenance procedures and wear limits.
• High pressure: Compressor discharge air is under significant pressure (e.g., 3-5 bar), and hot exhaust gas is also pressurized. Leaks can be hazardous.
• Noise levels: Operating turbochargers generate high noise levels (100-120 dB), requiring hearing protection in the vicinity.
• Hot oil/gas leaks: Leaks can ignite on hot surfaces, leading to engine room fires. Regular inspection and immediate repair are crucial.

Class survey

Class surveyors will typically review the turbocharger's maintenance records, including running hours, previous overhaul reports, and any reported defects or repairs. They will perform a visual inspection for external leaks, signs of overheating, and security of mounting. They may request to witness the testing of the overspeed trip device (if applicable) and verify the functionality of safety alarms. If the turbocharger has been opened for maintenance (e.g., bearing inspection) prior to the survey, the surveyor may wish to witness the reassembly and clearance checks. Overall operational parameters (pressures, temperatures, vibration) will be checked against acceptable limits. Compliance with SOLAS and MARPOL regulations, especially regarding exhaust gas emissions monitoring, will also be verified if the turbocharger is part of an emissions-controlled system.

Estimated lifetime: 24,000 - 36,000 hours (before first major overhaul, with proper intermediate maintenance. The unit itself can last significantly longer with continuous maintenance and overhauls.)