How to Pick a Rotary Screw Compressor

Rotary screw compressors are fantastic machines. Reliable and dependable, rotary screw compressors can power a range of industrial applications and processes. But before you purchase one, there are a few things to consider. Let’s start with the basics.

How do rotary screw compressors work?

Rotary screw compressors are relatively simple machines.  Two twin rotors rotate in opposite directions drawing in air. As they rotate, the space between them decreases and compresses the air. The pressure ratio is determined by the length and pitch of the screw, as well as the form of the discharge port.

Because the rotary screw compressor does not have any other valves or mechanical parts, they can operate at high speeds and produce a large flow rate.

What are the benefits of a rotary screw compressor?

• Low noise output that meets OSHA requirements
• 50 percent lighter than compressors that produce comparable flow rates
• Infrequent maintenance requirements
• Less oil consumption and extremely low oil carryover (as low as 3 ppm)
• Less heat generation that other types of compressors
• No reduction in capacity throughout compressor lifetime 

Which applications should use rotary screw compressors?

If you have a high-volume, continuous commercial or industrial application, a rotary screw compressor may be right for you. Smaller jobs, like DIY projects and air for pneumatic hand tools, don’t require the power and flow of a rotary screw compressor. If you only need air intermittently and for low-flow applications, this type of compressor isn’t for you.

Have a sensitive application that requires pure air? Rotary screw compressors are available in oil-free versions, as well as traditional oil-injected models.

How do I find the right rotary screw compressor for my application? 

The first step in selecting any compressor is assessing your facility’s needs. After you’ve calculated your required flow and whether or not you’ll require oil-injected or oil-free, reach out to one of our experts. Atlas Copco has an extensive line of rotary screw compressors to meet your air demands.