TROUBLE WITH BELLOWS
20th Apr 06
The vessel had just come under the management of this particular company.
She had a Mitsubishi 8UEC 75LS II main engine of 32,000 BHP. During takeover we observed unit no: 8 exhaust valve expansion bellow leaking and temporarily patched it up.
There was a spare expansion bellow onboard. Due to commercial constraints vessel sailed out and engine room was kept manned at all times.
During passage observed that the leakage had slightly increased. At bunker point expansion bellow was removed and renewed from the spare. The spare bellow which was neatly packed was not original but one fabricated by a shore workshop.
Head office was informed and raised requisition for a spare expansion bellow makers. After sailing for 10 days observed unit no: 8 exhaust temp high and at alarm condition.
Engine was stopped and expansion bellow removed; observed inner sleeve ruptured and exhaust passage from exh. valve to exhaust manifold blocked by about 50%. On inspection of unit through scavenge port observed no: 2 piston ring broken.
Exhaust manifold inspected; found lot of metal particulate inside the manifold and on the after turbocharger inlet grid. All metal particles cleared.
Unit opened up, decarbonised, inspected, calibrated and all piston rings renewed. Unit boxed back and old original expansion bellow repaired and fitted. Engine started and voyage continued with manned engine room. At next port received original expansion bellow from makers and same fitted.
Conclusion: Always have one spare original expansion bellow onboard. Never use fabricated spares because if the metal particles had entered the turbo charger there would have been extensive damage. Always renew a leaky below at the earliest as it is a fire hazard and risky when vessel is sailing in narrow congested waters.