If you’re in the market for a new air compressor, you may be wondering if you should purchase a single stage or 2 stage compressor, and more importantly, what’s the difference between the two?
Single Stage vs. Two Stage Air Compressor
The main difference between a single and 2 stage air compressor is the number of times that air gets compressed between the inlet valve and tool nozzle. In a single stage compressor the air is compressed one time; in a two stage compressor the air is compressed twice for double the pressure.
Process for a single stage / piston air compressor
- Air is sucked into a cylinder
- The trapped air is compressed in a single stroke with a piston at roughly 120 psi
- The compressed air is moved onward to a storage tank
- In the storage tank, the compressed air acts as the energy for the tools that the single stage air compressor is built to accommodate.
Process for a two stage / dual stage compressor
- The compressed air isn’t sent to a storage tank, it’s sent to a smaller piston for a second stroke at approximately 175 psi.
- The double pressurized air is cooled and delivered to a storage tank where it serves as energy for high powered equipment.
Be sure not to confuse the number of cylinders for the number of stages in an air compressor. Both a single and two stage compressor use two cylinders because it’s easier to balance air that way. The difference between the 2 stage air compressor vs. single stage in this regard is that in the single stage both cylinders are the same size. In a two stage air compressor the second piston is shorter than the first, the two are linked by a cooling tube that brings the air temperature down before the second round of compression.
When to use a Single Stage Air Compressor
A two stage air compressor produces higher air power, making them a better choice for large scale operations and continuous applications. But, they also cost more, making them a better option for factories and workshops than for private use. For the independent hobbyist or craftsperson, a single stage compressor will easily power a variety of handheld pneumatic tools that don’t exceed 100 psi. At auto shops, pressing plants and other settings that require a complex system of air powered machinery, higher capacity 2 stage air compressors are preferred.
Out of all the activities and hobbies that you could do in your garage or backyard, few require as many tools as woodworking. From cutting and sawing to drilling, nailing and sanding, there’s an essential tool used every step of the way, regardless of whether you’re making a custom canoe, table, or accessory.
For every woodworking tool that requires a lot of physical exertion, there’s a pneumatic equivalent to bear the brunt of the work. Air powered saws and drills allow you to cut each board and drill every hole evenly and easily in a matter of seconds – no strained wrists or overworked shoulders. Best of all, each application is accomplished in a fraction of the time.
With a single stage air compressor you could power just about every woodworking tool you own, making it possible to achieve in minutes what would otherwise take hours with old fashioned hand tools.
Single stage air compressor tasks:
Sawing: A pneumatic speed saw can slice through wood in a fraction of the time that it would take to manually run carbide blades from one end of the board to another. Air powered speed saws can be fitted with blades of various lengths for different board thicknesses.
Nailing: How many times has your nail gone in the wrong way because of hard, impenetrable depth or because the nail wasn’t straight in the first place? An air–powered nailer sends nails in straight and even while penetrating thicknesses with no problems at all. Best of all, it will do all of this in seconds, and you rarely suffer a poke to the thumb in the process.
Drilling: Some people find operating a drill to be just as awkward as hammering a nail. A slip of the wrist or elbow could send the drill in crooked or cause the hole to spread too wide for the allotted nuts and bolts. A drill is also a really powerful device, which can be problematic if you fire off target and send a line of holes off balance. These risks are greatly reduced with the use of an air powered drill, which can drill holes through a 2×4 faster, and with better accuracy.
Sanding: A good sanding job makes all the difference between an amateur and professional looking job. Sanding by hand allows you to be very precise, but machinery can handle the job in a fraction of the time – giving you a really smooth finish. Using an orbital pneumatic sander can offer a streak-free finish on all types of wood surfaces.
If woodworking is a trade made easier with the use of an air compressor, metal work is virtually impossible without one. As the world’s strongest material, metal is a lot harder to cut, mold, drill, and join together. While it’s still very possible to power woodworking tools with your own physical strength, the same cannot be said when working with metal. Metal projects require electric or air–powered tools that go above and beyond human capabilities.
The following tasks can be performed within seconds on metal, using a single stage compressor and the appropriate tools:
Shearing: Metal alloys need to be molded a certain way in order for the finished product to come in a specified shape. However, many people don’t realize the power of pneumatic metal cutting tools. With an air powered shear, metal workers can cut through sheets of metal just as they would cut cardboard with a rotary cutter.
Grinding: For material that’s supposedly impervious, pneumatic grinders can work wonders. Whether you need to cut a long brass bar in half or trim an inch off the edge of an aluminum pipe, it can all be done in under a minute with an air powered grinder. Attach the grinder to a single stage air compressor and it can be especially useful when that small but critical metal piece is just a few millimeters too wide to fit within a corresponding space.
Riveting: Welding is not the only way to join metal pieces together. In the fabrication of metal drawers or cabinets, plates of metal are joined in a similar manner to panels of wood when creating furniture, only the fasteners are different. When metal sheets are combined to build sheds and other structures, rivets are oftentimes the fastener of choice. Using a pneumatic riveter, you can join two metal panels tight along the seams in seconds. The pneumatic riveter sends pin-like fasteners through pre-made metal holes for a tight, secure fit.
Ratcheting: Sometimes you come across a metal fastener that needs to come undone, but as you’ll quickly find out, time can act as a natural welder. When a nut has been screwed on tight as can be, with the intent of never being unscrewed, you’re going to have your work cut out for you if you’re using a standard wrench. When you come across this issue, you can use an air powered ratchet, which will break those impossible nuts loose from the bolts and allow you to disassemble the item, regardless of how long the two have been connected. Within seconds, a ratchet can separate what would have otherwise ended up joined together forever in a landfill.
All of these wood and metal applications can be performed independently with tools that operate at 90 psi or under with a single stage air compressor.
When to use a 2 Stage Air Compressor
Manufacturing, Auto Assembly and Maintenance
Given the amount of heavy duty applications necessary in manufacturing, assembly plants, and vehicle construction, pneumatic tools are a necessity. Unlike personal crafts and small scale operations, assembly plants and manufacturing facilities need more than 100 psi to perform vehicle construction and maintenance.
2 stage compressor tasks:
Lifting: Almost every manufacturing plant requires parts be lifted, sometimes weighing upwards of a ton or more. A two or three stage air compressor can be used to power lifting devices with suctions strong enough for heavy loads.
Screwing: Every production facility is going to see parts that need to be screwed and bolted together at some point on the line. With air powered impact wrenches and ratchets, work crews can quickly assemble and disassemble parts, so that each component can be moved along the conveyer with utmost efficiency.
Greasing: An engine consists of several key parts that are continually in motion during vehicle operation. Most of these moving parts are made of metals that would grind together and wear out from friction if not lubricated. As with most machines, including air compressors, grease is a vital part of the puzzle. At assembly plants, pneumatic powered greasers apply lubricants on a variety of parts, some of which are difficult to reach or too hot to handle.
Painting: Achieving that glossy, smooth paint finish is no easy feat. The shell must be primed and coated in a clean environment, free of moisture or oil in both the pneumatic and atmospheric air. A 2 stage compressor can be used to power paint sprayers, which provide streak free coats for an overall smoothness that could never be achieved with spray cans or rollers.
Two and three stage compressors are also ideal for powering pneumatic tools and machinery along the production lines at furniture factories and food packing plants.
Learn More About a Single or 2 Stage Air Compressor
Regardless of the size of your project or scope of your operation, air powered tools are essential to your productivity. As an independent woodworker or the owner of a crafts line, a single stage ELGi air compressor could drastically improve workflow and efficiency. If you manage a work crew at a large pressing plant, a 2 stage ELGi air compressor could be used to power the most heavy duty aspects of your operation.
Michigan Air is a leading provider of ELGi Air Compressors, one of the most trusted names in the business. To learn more about our small portable and large stationary units, visit our shop page.
Questions? Contact us for more information and advice on maintaining your compressed air system. Michigan Air Solutions is a reliable source for helpful compressor maintenance information. We also offer a wide selection ELGi air dryer systems. Our customers are located in Grand Rapids, Detroit, Lansing, and everywhere in between.