Pneumatic Design: The Single-Acting Cylinder VS. Double-Acting Cylinder

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When an industrial system is in its design phase, most configurations require linear motion. That’s when hydraulic or pneumatic cylinders come into play. They use liquid or air to create motion in a particular direction. If you’re familiar with any hydraulics, you know that there are many cylinders to choose from. Examine the benefits and drawbacks when it comes to single action vs double action cylinders. The details may help you choose the right configuration.

The Basic Difference

The main difference between single and double action cylinders is the number of ports. Single-action designs have one port, whereas double-action components have two ports. The single port allows hydraulic fluid to flow into the cylinder in one direction. In contrast, the fluid entering a double acting hydraulic cylinder can both enter through one port and exit out the opposite one. Both designs are viable for their particular applications, which means that you must make an educated decision when a selection must be made.

Strong Versatility

According to Hydraulics & Pneumatics, the double acting hydraulic cylinder is the most common type across multiple industries. It’s simply more versatile. Hydraulic power is available in both directions across the cylinder. A push-and-pull motion makes machinery control easier.

Single acting hydraulic cylinder designs have power in only one direction. Any piston retraction power that’s possible is performed by a spring. The retraction process may be governed by gravity in some cases. Because of these limitations in usage, the double-action design remains the most versatile choice in the industry today.

Spring Issues

A major concern with spring usage in a single acting hydraulic cylinder is longevity and accuracy, reports Parker Hannifin. Your cylinder may have precision work to complete, for instance. The piston must stop at a certain point along the cylinder’s length. A spring stretches and warps over time. Precision with springs isn’t usually possible.

When you compare single vs double action cylinders, you see the dual ports as being extremely accurate. They can practically stop on a dime.

Venting Concerns

Double-action cylinders are closed off from the environment. No particles or air infiltrates the interior. Single-action cylinders are different, however. The spring mechanism requires venting, which gives the assembly an outlet to the outdoors. It’s possible for particulates to enter the cylinder. Breakdowns and gradual decline may be part of this cylinder’s maintenance history.

Sizing Considerations

Comparing single action vs double action designs also encourages a basic-needs evaluation. You may simply need a good fit within your compact system. Single-action cylinders will win out in these scenarios. They have a single port and small housing. This design isn’t possible with a double-action cylinder. There must be extra room for the ports and fluid transfer in these designs.

Compliance with ISO Standards

Another item to consider is meeting compliance standards. ISO standards are in place so that every industry is safe and cohesive with their operations. As you compare single vs double action designs, the ISO standards might guide your decision. Most ISO requirements involve double-action cylinders.

Ideally, verify the standards before you take on any updates. Compliance is critical in any industry.

Cost Comparison

As you compare single vs double action cylinders, you realize that cost is definitely a defining difference. Single-action cylinders will be cheaper to purchase and install. You have only one port to support instead of the dual design from a double acting hydraulic cylinder.

Avoiding any hydraulic failures within the system is always the goal. Both piping and valve purchases are suddenly less expensive than with a dual configuration. When initial cost is factored in, the single-action design wins out every time.

Work closely with Motion & Flow Control Products when you need the perfect cylinder. The difference between single and double action designs is quantifiable. One is typically better than the other, depending on your application. You’ll end up with a design that serves your business best through the years.