This specification specifies the requirements, quality assurance regulations and delivery preparations for marine diesel engine air coolers (hereinafter referred to as air coolers). This specification is applicable to water-side design pressure not greater than 0.5MPa, inlet design temperature is 32°C, air-side design pressure not greater than 0.35MPa, design temperature not higher than 270°C, the cooling medium is seawater, and the cooled medium is pressurized air Design, manufacture and inspection of air coolers.