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Hitachi Ltd
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Hitachi Ltd
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Publication date
Application filed by Hitachi LtdfiledCriticalHitachi Ltd
Priority to JP12717876ApriorityCriticalpatent/JPS5352924A/en
Publication of JPS5352924ApublicationCriticalpatent/JPS5352924A/en
PURPOSE: To certainly provide a preventive maintenance with a corrosion made previously known in the cooler pipe, by means of providing a pilot pipe, made of the same material as the cooler pipe and of construction with a thin thickness, in series to a pipe of the water cooler for cooling the insulation oil.