Читать книгу Hydraulic Fluid Power - Andrea Vacca - Страница 83

Even though the orifice element is described by a single equation (Eq. (4.5)), an orifice can assume different roles in a hydraulic circuit. A first way to classify an orifice function is based on its location in the system: in fact, orifices can be present either in the working and return lines or on the pilot lines of the systems. The working and return lines are represented by the connections to/from the actuators of the system; the power transfer functions achieved by the system occur in these lines. Thus, these lines are usually characterized by significant values of flow rate and pressure. Pilot lines are instead used to transmit pressure information to different locations of the system. These latter lines usually have negligible flow rates and are used for control purposes. According to ISO1219‐1 [1], pilot lines are always indicated with dashed lines, while working and return lines with a solid line.