In a single-acting hydraulic cylinder, how is the return stroke typically achieved?

In a single-acting hydraulic cylinder, how is the return stroke typically achieved?

• A. By hydraulic pressure in the opposite direction
• B. By manual reset
• C. By an external spring or gravity
• D. By electric actuation

Answer: (C)

In a single-acting hydraulic cylinder, hydraulic pressure is used to extend the piston in one direction, and there isn’t hydraulic pressure on the opposite side to return it. A restoring force is required, and that comes from a spring (often internal) or from gravity, depending on how the cylinder is oriented. When the hydraulic pressure is released, the spring pushes the piston back, or gravity pulls it back toward the retracted position, completing the return stroke. If you needed the return to be powered by hydraulic pressure, you’d use a double-acting cylinder instead.

In a single-acting hydraulic cylinder, hydraulic pressure is used to extend the piston in one direction, and there isn’t hydraulic pressure on the opposite side to return it. A restoring force is required, and that comes from a spring (often internal) or from gravity, depending on how the cylinder is oriented. When the hydraulic pressure is released, the spring pushes the piston back, or gravity pulls it back toward the retracted position, completing the return stroke. If you needed the return to be powered by hydraulic pressure, you’d use a double-acting cylinder instead.