TPS-D 61-D

Common issues

• Bearing wear (journal and thrust bearings) leading to increased axial/radial play and potential rotor contact.
• Compressor fouling due to intake air contamination or oil carry-over, reducing air flow and efficiency.
• Turbine fouling and erosion/corrosion from exhaust gas (especially with HFO operation), leading to reduced power and increased exhaust back pressure.
• Nozzle ring and diffuser damage (cracks, erosion, burning) impacting turbine efficiency and gas flow.
• Oil leakage from bearing casing seals, indicating seal wear or improper oil drainage.
• Rotor imbalance or vibration, often caused by fouling, blade damage, or bearing issues, leading to premature wear.
• Casing cracks (especially turbine casing) due to thermal cycling and stress.
• Surging, often an engine-related issue but manifesting as unstable turbocharger operation, causing mechanical stress.

Inspection checklist

• Measure axial and radial play of the rotor shaft to assess bearing condition.
• Inspect compressor wheel for cleanliness, blade damage (nicks, bends), and rubbing marks on the casing.
• Inspect turbine wheel for cleanliness, blade damage (erosion, burning, cracks), and rubbing marks.
• Examine nozzle ring and diffuser for fouling, cracks, erosion, and proper seating.
• Check for oil leaks around bearing casings, oil supply/drain lines, and air intake/exhaust ducts.
• Verify lubricating oil pressure and temperature within specified limits; inspect oil filter condition.
• Assess air filter condition and cleanliness; ensure no foreign object damage (FOD) risk.
• Inspect exhaust gas casing for cracks, hot spots, and insulation integrity.
• Check security of all mounting bolts, pipe connections, and support structures.
• Monitor turbocharger performance parameters: boost pressure, exhaust gas temperatures (before/after turbine), and RPM.

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Bearing cartridges (complete set for journal and thrust bearings)
• Oil seals and O-rings for bearing casing and oil lines
• Gasket sets for casing joints and connections
• Air filter elements (if applicable to the specific intake system)
• Lubricating oil filter elements
• Nozzle ring segments or complete nozzle ring (depending on design and application)
• Mounting bolts and nuts (especially for hot sections)

Safety

• Extremely high temperatures of exhaust gas and turbine casing (risk of severe burns).
• High rotational speeds of the rotor (up to 60,000 RPM or more) pose a risk of rotor burst if overspeed or severe imbalance occurs.
• Pressurized air and exhaust gas lines (risk of injury from sudden release).
• Hot lubricating oil under pressure.
• High noise levels requiring hearing protection during operation and inspection.

Class survey

Class surveyors typically focus on overall operational integrity and safety. They will check for external oil/gas leaks, excessive vibration, and general cleanliness. Key areas include verification of bearing play measurements against manufacturer's limits, inspection of safety devices (e.g., overspeed trip functionality if fitted), condition of air intake filters, exhaust gas casing integrity and insulation, and proper functioning of the lubricating oil system (pressure, temperature). Maintenance records, running hours, and previous survey reports will be reviewed. Performance parameters like boost pressure and exhaust gas temperatures are often checked against engine design data.