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

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

• A. A single-acting cylinder uses pressure in both directions
• B. A double-acting cylinder uses springs for return
• C. A hydraulic cylinder uses air pressure to operate
• D. A double-acting cylinder uses pressure in both directions

Answer: (D)

The main idea is that a double-acting hydraulic cylinder uses hydraulic pressure to move the piston in both directions. With two fluid ports, you can push fluid to one side of the piston to extend the rod, and push fluid to the opposite side to retract it. Because the fluid does the work for both strokes, there’s no need for a spring or external load to return the piston. In contrast, a single-acting cylinder uses pressure in only one direction to extend, and relies on a spring or gravity to return the piston. Also, hydraulic systems use liquid fluid, not air, so using air pressure isn’t how these cylinders operate.

The main idea is that a double-acting hydraulic cylinder uses hydraulic pressure to move the piston in both directions. With two fluid ports, you can push fluid to one side of the piston to extend the rod, and push fluid to the opposite side to retract it. Because the fluid does the work for both strokes, there’s no need for a spring or external load to return the piston. In contrast, a single-acting cylinder uses pressure in only one direction to extend, and relies on a spring or gravity to return the piston. Also, hydraulic systems use liquid fluid, not air, so using air pressure isn’t how these cylinders operate.