GEAR AS 9Y3520 - Caterpillar

Gen Set EngineC18 MARINE GS (S/N: CYN1-UP)C32 MAR GS ENG (S/N: RNE1-UP; RNX1-UP)Generator SetC18 MARINE GS (S/N: GBM1-UP; GEN1-UP; MGS1-UP)C32 MARINE GS (S/N: RNF1-UP)C9 MARINE GEN (S/N: SJB1-UP)C9 MARINE GS (S/N: C9A1-UP)Marine Engine3406E MARINE (S/N: 9WR1-UP)C-12 MARINE (S/N: K1M1-UP; 9HP1-UP)C12 MARINE (S/N: NFL1-UP; C1Z1-UP)C15 MARINE (S/N: RLA1-UP)C18 (S/N: JLE1-UP)C18 MARINE (S/N: WKB1-UP; PLE1-UP; CKH1-UP; C1J1-UP; GES1-UP; KJT1-UP; JKX1-UP; NAX1-UP; NAY1-UP)C18 MARINE ENG (S/N: J2K1-UP; T2P1-UP)C30 MARINE (S/N: CLX1-UP)C32 MARINE (S/N: RXB1-UP; RNC1-UP; RND1-UP; RPM1-UP; RNR1-UP; SLT1-UP; T3T1-UP; RNY1-UP; RNZ1-UP)C7 MARINE (S/N: M7A1-UP; C7B1-UP; C7D1-UP; M7G1-UP; C7X1-UP; C7Z1-UP)C9 (S/N: C9Y1-UP)C9 MARINE (S/N: C9B1-UP; CSN1-UP; X9X1-UP; Z9X1-UP; X9Y1-UP)The sea water-cooled aftercooler core is a consumable component of the engine and has a limited service life due to the environment that operates in. Sea water aftercooled (SWAC) engines are subject to two types of corrosion, galvanic corrosion, and electrolysis which require sacrificial zinc rods (Anodes) to reduce both forms of corrosion. Depletion rate of the zinc rod depends on water salinity, oxygen levels, type of metal in contact with the sea water and levels of electrolysis. Electrolysis is caused by stray current that can be generated by ship board wiring, on board electrical components, bad shore power supply bleeding into water or from nearby vessels that have electrical issues. Galvanic corrosion is an electro chemical reaction between two or more dissimilar metals connected through sea water. For engines that do not have frequent usage, levels of galvanic corrosion and electrolysis can be highly variable and may deplete sacrificial zinc anode when the engine is not being used. Depletion of sacrificial zinc anode beyond the useful capacity may allow these two forms of corrosion to attack the aftercooler core.High sea water velocity and lack of sea water cleanliness can also affect the life of the aftercooler core. Large debris that passes sea water strainer can partially plug internal water passages of the aftercooler core, raising sea water velocity in the open passages which can erode the core passages. Sea strainer designs that avoid large debris from bypassing the strainer during operation or during cleaning or servicing are needed to keep the aftercooler core clean.The Operators & Maintenance Manual has a clean and test requirement 1000 hour or 2 years, whichever is first. Replacement of the core is at top end or major overhaul intervals may vary based on the specific engine model. Replacement of the core at 6 years can greatly reduce the risk of core failure associated with the aforementioned conditions.