Hydraulic symbols: Part one: General symbols and symbols of measuring instruments and indicators

Hydraulic power transfer and management systems are widely used in modern agriculture, especially in agricultural engineering and the associated processing industry. They can be very simple, but also extremely complex, when precise matching of the interaction of their components in real time is very difficult to controll and achieve. In addition, the designs of a number of hydraulic components is sufficiently complicated for detailed representation on the corresponding hydraulic installation. In all cases, analyzing the performance characteristics of components and the entire hydraulic system, as well as understanding the structure of the hydraulic system, is of great importance. One of the generally accepted ways to facilitate and speed up these processes is the application of schematic diagrams of hydraulic systems and their subcircuits. Officially, hydraulic symbols are defined by ISO industry standards. Therefore, ideally, all hydraulic schemes should be configured using universal graphic symbols. Unfortunately, this is not always the case in technical practice. Depending on the manufacturer and/or dealer of the hydraulic equipment, the symbols of the associated schemes vary in a smaller or a greater extent. The real reasons for the existence of these differences can only be assumed. According to some authors, companies want their drawings to differ from the hydraulic schema of competitors. Therefore, the most commonly used hydraulic symbols are presented in this paper.