How does a single acting cylinder differ from a double acting cylinder?

A single acting cylinder operates by utilizing pressure to extend the piston in one direction while relying on a return mechanism, such as gravity or a spring, to retract. This design limits the power application to only one direction, which is why it is termed 'single acting.'

In contrast, a double acting cylinder uses pressure to move the piston in both directions, being capable of providing force for extension and retraction. This versatility allows it to be more effective in applications requiring continuous motion in both directions.

The other options refer to aspects of design and maintenance that do not fundamentally address the operational differences between the two types of cylinders. Therefore, understanding the specific functionality of a single acting cylinder, which only powers in one direction, highlights why it is distinctly classified in this way.