AT14

Common issues

• Compressor fouling (due to dirty intake air, oil carry-over)
• Turbine fouling (due to poor fuel combustion, exhaust gas deposits)
• Bearing wear (journal and thrust bearings, leading to excessive rotor play)
• Oil leakage (from bearing housing seals, oil supply/drain connections)
• Rotor imbalance (caused by fouling, blade damage, or bearing wear leading to vibration)
• Casing cracks (especially turbine casing due to thermal stress cycles)
• Exhaust gas leaks (from turbine casing joints, expansion bellows, or manifold connections)
• Foreign Object Damage (FOD) to compressor or turbine blades

Inspection checklist

• Check rotor axial and radial clearances using a dial gauge (critical indicator of bearing wear).
• Visually inspect compressor and turbine blades for fouling, erosion, cracks, or foreign object damage (FOD).
• Inspect bearing housing and oil lines for any signs of oil leakage.
• Verify the condition of the air filter element (if fitted) for clogging or damage.
• Check for exhaust gas leaks around turbine casing joints, expansion bellows, and exhaust manifold connections.
• Inspect compressor and turbine casings for cracks, deformation, or loose fasteners.
• Ensure oil drain lines are clear, correctly sloped, and free from restrictions.
• Manually rotate the rotor (when cold and safe) to check for smooth rotation and absence of rubbing.
• Monitor turbocharger vibration levels during operation (if instrumentation is available).

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 Kit (Journal bearings, thrust bearing, thrust collar)
• Oil Seal Rings (compressor and turbine side)
• Gasket Set (for casing joints, oil lines)
• O-ring Kit
• Air Filter Element (if applicable)
• Locking Plates/Washers for critical fasteners

Safety

• High Temperatures: Turbine casing and exhaust gas piping operate at extreme temperatures (300-600°C). Risk of severe burns.
• High Rotational Speed: Rotor operates at tens of thousands of RPM. Catastrophic failure (burst) can release high-energy projectiles.
• Hot Oil/Pressure: Oil supply lines can be hot and under pressure. Risk of burns and spray.
• Exhaust Gas Leaks: Risk of carbon monoxide (CO) poisoning in enclosed spaces.
• Rotating Parts: Never approach or open while running. Ensure proper lockout/tagout procedures before maintenance.

Class survey

During annual or special surveys, the class surveyor will typically check: 1. Operational Test: Verify proper operation, alarm functions (e.g., high exhaust temperature, low oil pressure if integrated). 2. Safety Devices: Check over-speed trip mechanism (if fitted or engine-integrated) and its functionality. 3. Casing Integrity: Visual inspection for cracks, deformation, or signs of exhaust gas/oil leakage. 4. Mounting & Foundations: Ensure secure mounting and absence of excessive vibration. 5. Exhaust Gas System: Inspect expansion bellows, insulation, and connections for leaks. 6. Lubricating Oil System: Verify oil supply pressure, temperature, and drain flow. 7. Maintenance Records: Review logbooks for service history, bearing replacements, and overhaul dates. 8. Spare Parts: Confirm critical spares are onboard as per Class/ISM requirements. 9. Overall Condition: General assessment of cleanliness, absence of leaks, and signs of distress.