What is the schematic symbol for a flow line in a hydraulic system?

The correct representation of a flow line in a hydraulic system is indicated by a straight horizontal line. In hydraulic schematics, flow lines are essential as they depict the paths through which hydraulic fluid moves. These lines typically represent the flow direction and are crucial for understanding the system's operation. The use of a straight line for this purpose provides clarity and consistency, allowing individuals working with hydraulic systems to quickly interpret how fluid travels from one component to another.

The other shapes mentioned do not accurately convey the flow line in hydraulic schematics. For example, an upside-down triangle or any forms such as "E" lying flat or a diamond shape with a dotted line may represent other components or functions within a schematic, but they do not depict a flow line, which is straightforwardly represented by a horizontal line. Understanding these symbols properly is vital for anyone involved in maintenance or construction of hydraulic systems.