(1) According to the working principle, structure classification 1) Vane pump: Driven by centrifugal force or axial force, all kinds of impeller blades rotate through the pump shaft to transport liquid to pipe or container such as centrifugal pump, vortex pump, mixed flow pump, Axial flow pump. 2) positive displacement pump: the use of continuous changes in the volume of the pump cylinder liquid delivery pump, such as reciprocating pump, piston pump, gear pump, screw pump. 3) Other types of pumps: Electromagnetic pumps that use electromagnetic to deliver liquid electrical conductors; Pumps that use fluid energy to deliver liquids, such as jet pumps, air boosters, etc. (2) Classification according to chemical industry 1) Process flow pump: including feed pump, return pump, circulating pump, flushing pump, sewage pump, replenishment pump, output pump and so on. 2) Utility Pump: Including boiler pump, cooling tower pump, fire pump, water pump with deep well. 3) Auxiliary use pump: Including lubricating oil pump, seal pump, hydraulic pump and so on. 4) pipeline pump: pipeline pump, loading and unloading pump and so on. (3) According to the transmission medium classification 1) Pump: Including water pump, boiler feed pump, condensate pump, hot water pump. 2) Corrosion-resistant pump: Including stainless steel pump, high silicon cast iron pump, ceramic acid pump, impermeable graphite pump, hard rubber pump, hard polyvinyl chloride pump, shield pump, diaphragm pump, titanium pump and so on. 3) Impurity pump: Including slurry pump, sand pump, sewage pump, pulverized coal pump, ash pump and so on. 4) oil pump: cold oil pump, hot oil pump, oil pump, liquid hydrocarbon pump. (4) Classified according to the conditions of use 1) High flow and micro-flow pump: flow rate is 300m³ / min and 0.01L / min respectively; 2) High temperature pump and low temperature pump: High pressure pump and low pressure pump: high pressure up to 200MPa, vacuum degree is 2.66 --- 10.66kPa (20-80mmHg); 4) high speed pump and low speed pump: high speed up to 24000r / min, low speed 5-10r / min; Metering pump: flow measurement accuracy of ± 0 3%; 6) high viscosity pump: Viscosity up to several thousand Pa (Pa · s).