主檆関ピストンスカートからの冷却油漏洩

摘要

While piston rings and liners were inspected through the scavenge ports from the scavenge box for periodical inspection of the main engine, the piston where cooling oil had leaked from a hole at the interior of the piston skirt was discovered. After replacing the piston concerned with a spare piston, an air pressure test was carried out for the piston. Leakage of cooling oil from a jack bolt hole which is used to split a piston into a piston crown and skirt was confirmed by the test. Then the piston was split into the piston crown and skirt and inspection was carried out. The inspection revealed that there were scratches and marks of applied silicone sealant on the mating surface (where metal-to-metal contact is required) of the piston crown and skirt.%主機関定期点検のため、掃気室からピスト ンリング、シリンダライナの点検を実施した ところ、ピストンスカート下部の穴から冷却 油の漏洩があるピストンが確認された。 当該ピストンを予備ピストンと交換、漏油 が認められたピストンの圧力テストを実施し たところ、ピストンクラウンとピストンスカー トを分割するためのジャッキボルト穴から漏 洩が確認された。