When it comes to selecting the right option for your specific task, it helps to better understand the key differences between single-acting and double-acting hydraulic cylinders.

Whether you’re planning the selection of hydraulic components or undertaking repairs on hydraulic cylinders, comprehending the type of cylinder you’re dealing with is critical. To that end, this article will equip you with the knowledge to differentiate between single-acting and double-acting cylinders and empower you to select the most suitable option for your operation’s requirements.

Key Differences Between Single Acting & Double Acting Cylinders

Fluid Application and Port Configuration

Single-Acting: These cylinders feature a single fluid connecting port for oil entry. This pressurised oil acts solely on one side of the piston, driving a unidirectional extension. This simpler design translates to a more cost-effective option.
Double-Acting: Conversely, double-acting cylinders boast two dedicated ports. This allows pressurised oil to be directed to either side of the piston, enabling meticulously controlled extension and precision retraction in both directions. This bi-directional capability necessitates a more complex design with additional seals.

Retraction Mechanism

Single-Acting: The return stroke of a single-acting cylinder relies on external forces. This could be a pre-loaded spring, the structural weight of the attached load (gravity), or even the action of another cylinder. This dependence on external factors limits precise control over retraction speed.
Double-Acting: Double-acting cylinders utilise the power of pressurised oil for both extension and retraction. This allows for precise control over the entire piston movement, making them ideal for applications demanding bi-directional actuation with defined speeds and positioning.

Complexity and Cost

Single-Acting: The simple design of single-acting cylinders, with their single port and reliance on external retraction mechanisms, translates to lower initial costs and easier maintenance requirements.
Double-Acting: The increased complexity of double-acting cylinders, with their two ports and seals for bi-directional flow, typically results in a higher initial investment. However, the added functionality and precise control over movement often justify the higher initial investment.

	Single Acting	Double Acting
Connecting Ports	One (1)	Two (2)
Retraction Method	Extends with pressure, retracts with spring / gravity	Extends and retracts with pressure
Advantages	✔ Simplicity ✔ Requires just 1 hose per cylinder ✔ Cost Effective ✔ Low Maintenance	✔ Precision ✔ Quick retraction ✔ Suits repetitive actions ✔ Applies push and pull forces
Disadvantages	✘ Pushes in one direction only ✘ Less control in retraction ✘ Fatigue Prone Design	✘ Multi-channel operation ✘ Needs 2 x hoses ✘ Investment Cost ✘ 4-way valve integration
Applications	• Simple lifting / pushing tasks • When fast retraction is not essential • All industry applications – from light to heavy industrial and commercial	• High cycle applications • Bi-directional actuation • Precise return control

Choosing the Right Cylinder: A Matter of Application

The selection of the appropriate hydraulic cylinder depends on a thorough understanding of your specific operation requirements. When precise control over both extension and retraction strokes is critical, a double-acting cylinder stands as the optimal choice.

Conversely, for straightforward applications demanding force in a single direction, a single-acting cylinder offers a compelling solution, balancing cost-effectiveness with operational efficiency.
By detailing the distinct functionalities of single acting and double acting cylinders, you can reaffirm yourself to make an informed decision that optimises your industrial automation processes. This knowledge ensures the selection of the most suitable hydraulic unit, contributing to the success of your project.

Contact Berendsen Fluid Power now to learn more about our comprehensive range of cylinders and discover the perfect choice for your application!