The hydraulic system and hydraulic power control signal composed of two parts , a signal control section for driving the hydraulic power of the control valve operation .

Hydraulic power circuit diagram representation of part is to show the relationship between different functional components . Hydraulic pressure source comprises a hydraulic pump , hydraulic motor and the auxiliary element ; portion contains various control hydraulic control valve for controlling the flow of working fluid , the pressure and direction ; execution portion contains a hydraulic cylinder or a hydraulic motor according to the actual requirements selection.

In the analysis and design of practical tasks , the general block diagram of a display device in actual operating conditions . A hollow arrow indicates the signal flow , while the solid arrow indicates the flow of energy .

The basic sequence of operation of the hydraulic circuit - the control element ( 4/2-way valve ) and commutation spring return actuator ( double acting hydraulic cylinders ) and the extension and retraction of the relief valve to open and close . For the implementation of components and control elements , presentations are based on the corresponding circuit diagram symbols, which also describes the circuit diagram symbols were ready .

According to the system works , you can turn on all circuits are numbered . If the first actuator is numbered 0 , then the identifier of its associated control elements is 1 . If the corresponding actuator element and projecting identifier number, then the corresponding element identifier and the actuator retraction was odd. Not only deal with the hydraulic circuit are numbered , but also to deal with the actual device number , in order to find a system failure .

DIN ISO1219-2 standard defines the number of constituent elements , comprising the following four parts : device number, loop number , device number , and the identifier element . If the entire system is only one device, you can omit the device number.

In practice, another way is to number all the components of the hydraulic system be numbered consecutively , this time , the part numbers should be consistent with the component list number. This method is particularly suitable for complex hydraulic control system , the control loop are each numbers corresponding thereto .