Marine pump is one of the most widely used hydraulic machinery on ships. Marine pumps are mainly: (1) piston pumps, commonly used as hand pumps and pumps, such as bilge pumps; (2) rotary pumps, such as in the cabin fuel and oil pump; (3) centrifugal pumps, such as in the cabin Cooling pumps, fire pumps, ballast pumps and domestic water pumps, etc .; (4) jet pump, commonly used as cabin bilge pumps. Marine gas pressure delivery machinery Marine gas pressure delivery machinery are mainly air compressors and ventilators. Compressed air generated by the air compressor can be used to start the diesel engine, control the reversing mechanism and clutch of large diesel engine, whistle, washing the seabed door and so on. Ventilators are widely used in ships. Cabins, cargo tanks, fuel tanks, furnace cabins and the like are all forced to ventilate with ventilators. Refrigeration device used to regulate the temperature of the cabin, save food. Compression refrigeration units are commonly used on ships. A device to make fresh water from seawater. For ocean-going vessels, freshwater is needed to make up for the lack of water in the tank. Commonly used in ships is a boiling light system, that is, the seawater is heated and vaporized, and then condensed into fresh water. Auxiliary Boiler The hot water used in daily life of a ship, the heating in residential areas, etc., as well as the heating of fuel oil and lubricating oil all require a lot of heat and can usually be provided by the steam generated by the boiler. This type of boiler is called an auxiliary boiler to distinguish it from a main boiler in a steam power plant that supplies steam to a main engine. Ships sailing, you can also use the host of the exhaust gas boiler to provide steam, so as to achieve energy-saving purposes.