The Difference Between Piston and Screw Compressors

Air compressors are an invaluable part of many industrial operations. If you’ve ever looked at buying an air compressor, you’ve likely seen both piston and screw compressors. These different types of air compressors each have their benefits and drawbacks, but how do you determine which one is right for your business?

We’ll be breaking down the differences between piston and screw compressors and what can make one or the other better for your operation.

Table of Contents

What Are Piston Compressors?

Also known as reciprocating compressors, piston air compressors work with the help of large pistons driven by a crankshaft. These are the more traditional type of compressor, with a lot of moving parts. This design characteristic contributes to some of a piston compressor’s biggest downsides because it increases friction and heat. This variable makes it a bit less reliable and more likely to break down, along with adding more maintenance requirements.

Size is also fundamental with piston compressors. They’re quite a bit larger than screw compressors, partially because they need to be sized to produce more air than the application’s required cubic feet per minute (CFM). This additional sizing is necessary for the compressor to cycle appropriately and prevent additional wear and tear. The larger size calls for foundation and grouting because of the vibrations and unbalanced forces.

When we look at the advantages of piston compressors, the primary benefit is cost and expertise. They’re more cost-effective than their screw compressor counterparts and more workers are familiar with how they work, meaning maintenance and repairs are easier to come by with your existing staff. There’s no need to turn to outside experts for these jobs.

What Are Screw Compressors?

Screw compressors use two helical screws to compress the air, but the key difference is that the screws don’t touch each other. Since there’s no contact, there’s less wear and tear, reducing maintenance needs for screw compressors and making them more reliable. This mechanism provides other benefits for heat production, noise level, size, efficiency and oil content in output air.

One of the most valuable benefits of a screw compressor is the ability to run one continuously. Since there’s less risk for overheating and wear, it can run without a duty cycle. This advantage also means the compressor can be sized to a facility’s CFM requirements, rather than purchasing larger sizes that allow for duty cycles. With less valve cleaning required, there’s also minimal need to shut down the compressor to do so.

In addition to eliminating oversizing, screw compressors are also smaller by design. Their compact nature and quieter operation mean they can be placed closer to the application on a shop floor, reducing the need for piping. Screw compressors have a one-direction rotation that creates less vibration and allows them to be mounted on a skid without additional foundation.

With all of that in mind, what are the advantages of a screw compressor? These compressors overtake piston compressors in many areas and provide a long list of benefits. They’re faster, more efficient, quieter, more reliable and easier to move around. But those significant benefits come at a higher price point and more specialized care. Remember, you can offset some of the cost through greater energy and efficiency savings, the need for a smaller-capacity model and the elimination of foundation requirements.

Is a Piston or Screw Compressor Right for Your Project?

Is a Piston or Screw Compressor Right for Your Project?

When trying to decide which type of compressor is right for your facility or project, you’ll need to consider the different factors in which they differ, including:

  • Initial cost: If you don’t want to spend much money, a piston compressor will likely be more attainable, but remember to factor in the costs associated with any special placement needs like soundproof housings and foundation. You may also want to do a cost analysis to see if some of the other savings associated with a screw compressor would offset its extra initial cost.
  • Operating costs: Consider what it’ll cost to run your compressor every day. Use the Compressed Air & Gas Institute’s operating cost calculator to determine this value.
  • Efficiency: Screw compressors require less power to create more air flow and are much more efficient. Greater efficiency in a screw compressor can translate to significant energy savings. Still, there are ways to maximize your compressor’s efficiency regardless of style.
  • Noise levels: A screw compressor is much quieter than a piston compressor and can be more flexible in placement because of it. If buying a piston compressor, you’ll need to ensure proper placement that won’t cause undue stress on workers’ hearing.
  • Maintenance: How much maintenance will the equipment need in the first place? Piston compressors need more attention than screw compressors. Piston compressors need more frequent maintenance and cleaning, but they can often be done by existing staff, while screw compressors might call for outsourcing. Piston compressors also require more spare parts for repairs, while screw compressors have fewer components.
  • Size requirements: A piston compressor needs to be significantly larger than your CFM requirements due to the need for duty cycles. A screw compressor can be much closer to the size of your requirements.
  • Oil content: Screw compressors have oil separation systems and can provide more effective oil removal. Alternatively, piston compressors have higher oil concentrations because they lack an oil separation system and the piston and oil rings can wear out.
  • Continuous operation needs: Screw compressors can operate continuously since there aren’t any connecting parts that cause significant wear and tear or overheating. This capability makes them a valuable addition to facilities that want to keep things moving 24/7. Piston compressors must be cycled and run intermittently to prevent these effects.

The compressor that’s right for your business will need to be selected carefully based on your organization’s unique operating needs and goals. A company that starts with a piston compressor may outgrow it, so it’s essential to revisit your compressor costs regularly and determine which is right for your business.

Find the Correct Compressor From the Titus Company

Find the Correct Compressor From the Titus Company

There are a lot of compressors out there and many factors go into choosing one. Thankfully, the experts at the Titus Company are well-versed in air compressors, regardless of design. We’re happy to walk through your setup with you and help you find the right kind of compressor for reaching your business goals. The Titus Company is located in Pennsylvania, but we have air compressor sales and service experts who extend emergency services and preventative maintenance in the DelawareMaryland, North Virginia and New Jersey areas.

Reach out to us to talk with a pro today and learn more about how our piston and rotary screw air compressors can fit into your workflow.