1) Pressure: Pump is ued to pressurize the fluid in system according to need of pressure we can select pump as below
2) Speed of pump: if the speed of pump is increased beyond its rated speed then problems like cavitations takes place. This problem directly affect on efficiency & working of hydraulic system. 3) Flow of pressurized oil: Vol. of oil at output is measured in litre per min have flow of oil deciding speed of actuators 4) Efficiency of pump: Selection of pump depends on required efficiency like volumetric efficiency , mechanical efficiency, overall efficiency 5) Oil compatibility: The meaning of compatibility is nothing but acceptance .each pump is compatible to hy.oil but if used different oil, then pump will not give a good performance. 6) cost of pump: There are different varieties o pumps available in market according to application we can choose it by economical aspect cost of pump & its spares should be less.