Fluid power system diagrams require much more complex valve symbology than standard P&IDs due to the complicated valving used in fluid power systems. Valves provide the control that is required to ensure that the motive media is routed to the correct point when needed. Valves are the most complicated symbols in fluid power systems. The symbols for the various lines and termination points are shown in Figure 23.ДЇigure 23 Fluid Power Line Symbols Valves The sole purpose of piping in a fluid power system is to transport the working media, at pressure, from one point to another. The difference between them is that the point of the arrow touches the circle in a pump and the tail of the arrow touches the circle in a motor.ДЇigure 22 Symbols for Rotary Actuators Piping Note the similarity between rotary motor symbols in Figure 22 and the pump symbols shown in Figure 19. Several of the more common rotary symbols are shown in Figure 22. Rotary actuators are generally called motors and may be fixed or variable. Figure 21 illustrates several types of linear actuators and their drawing symbols. Linear actuators have some form of piston device. Actuators are classified as linear actuators and rotary actuators. These symbols are in Figure 20.ДЇigure 20 Fluid Power Reservoir Symbols ActuatorДЄn actuator in a fluid power system is any device that converts the hydraulic or pneumatic pressure into mechanical work. To convey this information, symbology conventions have been developed. Hydraulic reservoirs can be much more complex in terms of how the fluid is admitted to and removed from the tank. Pneumatic reservoirs are usually simple tanks and their symbology is usually some variation of the cylinder shown in Figure 20. Although the symbols used to represent reservoirs vary widely, certain conventions are used to indicate how a reservoir handles the fluid. Reservoirs provide a location for storage of the motive media (hydraulic fluid or compressed gas). Figure 19 provides common symbols used for pumps (hydraulic) and compressors (pneumatic) in fluid power diagrams.ДЇigure 19 Fluid Power Pump and Compressor Symbols Reservoirs Pneumatic compressors are represented by hollow arrow heads. Hydraulic pumps are shown by solid arrow heads. The basic symbol for the pump is a circle containing one or more arrow heads indicating the direction(s) of flow with the points of the arrows in contact with the circle. In the broad area of fluid power, two categories of pump symbols are used, depending on the motive media being used (i.e., hydraulic or pneumatic). Some of the symbols used in fluid power systems are the same or similar to those already discussed, but many are entirely different.ДЇluid power systems are divided into five basic parts: Fluid power includes either gas (such as air) or hydraulic (such as water or oil) motive media. Fluid Power Diagrams and SchematicsДifferent symbology is used when dealing with systems that operate with fluid power. Fluid power diagrams and schematics require an independent review because they use a unique set of symbols and conventions.ДЇluid power diagrams and schematics require an independent review because they use a unique set of symbols and conventions.

Hydraulic valve symbols autocad