Air compressors are available in two types: single-stage and two-stage. Ever got confused over the differences between a two-stage air compressor and a single-stage air compressor?
It seems to be a very popular discussion with air compressor users, and so we will present to you all the relevant information about and differences between the two variations of air compressor designs.
Table of Contents
- What is the Difference Between a Two-stage Compressor And a Single-Stage Compressor?
- Single-Stage vs Two-Stage Air Compressor Uses
- Which is Better? Single-Stage or Two-Stage?
- Which is More Reliable? Single-Stage or Two-Stage?
- Which is More Expensive? Single-Stage or Two-Stage?
- FAQs (Frequently Asked Questions)
- Other Types of Compressors Reading
What is the Difference Between a Two-stage Compressor And a Single-Stage Compressor?
Let’s get right into it. The biggest difference between a two-stage compressor and a single-stage compressor is the number of times the compressor compresses air between the inlet valve and tool nozzle. A single-stage compressor compresses air a singular time, while two-stage compressors compress the air twice, producing double the pressure.
Their processes are very similar, with only one minor difference. Here’s a brief look at both operations:
Single-Stage Operation Process
- Air is sucked into the cylinder
- The air is trapped and then compressed with the piston at around 120 PSI
- The air moves to the storage tank for use with attached tools
Two-Stage Operation Process
- Air is sucked into the cylinder
- The air is trapped and then compressed with the piston
- The air is then pushed to a second smaller piston for a second stroke around 175 PSI
- Pressurized air is cooled and sent to the storage tank for use with attached tools
So, a single-stage air compressor, or otherwise referred to as a piston compressor, has a relatively simple operation where the air is compressed and sent to a storage tank. A two-stage air compressor, or otherwise known as a dual-stage compressor, has a very similar operation but instead of air being sent to the storage tank after compression, it is sent to another piston for a second compression and then sent to the storage tank.
The configuration of the pump typically determines the number of compression stages. Air compressor pumps are available in a wide array of shapes, sizes, and piston configurations. This page focuses on single-stage and dual-stage compressors but there are also multiple-stage compressors, with 2+ stages.
As you should know by now, the biggest difference is that single-stage compress air once, and two-stage twice. Therefore, the most notable difference is the size of the cylinder and where the pistons are located on each type of compressor. Single-stage air compressors have both pistons the same size and so both the cylinders are also the same size. But, dual-stage air compressors have a large piston for low pressure and a small piston for high pressure, and so, one side of the cylinder is visibly larger than the other.
Single-Stage vs Two-Stage Air Compressor Uses
For the independent craftsman, single-stage air compressors will power a variety of handheld pneumatic tools that don’t exceed 100 PSI. Two-stage compressors, however, are able to produce higher airpower, making them better for large-scale operations and continuous applications. Any plant or auto shop with rather complex arsenals of tools or machinery will need the higher-capacity two-stage compressor in order to operate better.
Single-Stage Air Compressor Uses
Woodworking is one of the most tool-intensive activities that someone could do in their backyard or garage. From cutting and sanding, to drilling, nailing, or sawing, there’s a mass amount of tools that can be air-powered to help you complete projects such as making furniture or even fixtures for the house.
Pneumatic woodworking tools make the job significantly easier than when trying to cut or saw manually, you can get the job done in seconds without having to strain your wrists or overwork your shoulders. Not only this, but pneumatic woodworking tools allow little time to slip or ruin a project because they’re so fast.
Single-stage air compressors allow you to power a vast array of woodworking tools that make it possible to achieve these efficient and accurate traits. Some of the tasks you would be able to accomplish with a single-stage compressor include:
- Drilling – air-powered drills can provide you with greater accuracy and certainly drill a lot faster than awkwardly relying on you trying desparately not to slip and send a drill in crooked
- Nailing – single-stage compressors paired with a pneumatic nailing tool will allow you send a nail straight in and penetrate most thicknesses without a fuss compared to struggling to hammer the nail all the way through your wood manually
- Sanding – air-powered sanders move in multiple directions and give you a streakless and smooth finish on all types of wood, far more effective and a better finish than manually using sandpaper
- Sawing – pneumatic saws can be fitted with various blade lengths and thicknesses which will allow you to slice through wood in a fraction of time
Metalworking is another use of single-stage compressors that allows tasks to be performed in seconds with the appropriate tools. With metal being a lot harder to cut, drill, mold, and join together, air-powered devices are ever so important in the successful completion of tasks. Single-stage compressors allow users to conduct the following tasks:
- Grinding – single-stage compressors partnered with a grinding tool will allow you to grind critical metal pieces down a few millimeters to fit in a space with ease
- Ratcheting – air-powered ratchets will allow you to disassemble items by breaking long-stuck nuts loose from bolts, no matter how tight and long it may have be screwed
- Riveting – pneumatic riveters allow you to join two metal panels tight along the seams in a matter of seconds by sending pin-like fasteners through the metal holes for tight and secure fits
- Shearing – air-powered shears allow metalworkers to cut through sheets of metal as simple as cutting carboard with a rotary cutter
Typically, all of these metalworking and woodworking tasks can be performed efficiently with a single-stage unit and tools that operate at under 90 PSI.
Two-Stage Air Compressor Uses
Within the auto assembly and maintenance sector, two-stage compressors paired with pneumatic tools save untold amounts of energy. Typically the applications within auto assembly and maintenance industries will require more than 100 PSI which is why the single-stage compressor is not suited here. Two-stage compressors make it possible to pneumatically drive the following applications:
- Greasing – in assembly plants, a two-stage compressor powering a greaser will apply lubricants on various car parts that are otherwise too hot to handle or extremely difficult to reach
- Lifting – a two-stage compressor can be used to powerlift devices with suctions strong enough for heavy loads, this helps lift cars overhead so that the finishing touches can be applied
- Painting – a two-stage air compressor can power a paint sprayer, which will provide you with blotch-free and streak-free finishes which are ever so desirable
- Screwing – when using pneumatic impact wrenches and ratches with a two-stage air compressor you can quickly assemble and disassemble vehicle parts to allow them to move down the conveyor with efficiency
It’s not just two-stage compressors that are suited to this industry, three-stage or multi-stage compressors can also be ideal for powering these types of tools and machinery.
When it comes to bottling beverages for mass distribution, dual-stage compressors are ideal for the processes employed along with the conveyor systems at food and beverage processing plants. Two-stage compressors are vital in turning out thousands and thousands of units per day with the following processes:
- Filling – pneuamtic machines fill each bottle with a preprogrammed amount of beverage
- Labelling – in most cases, pneumatically powered robotic arms will apply a label to the bottle
- Molding – air-powered dryers help solidify molded glass after pneuamtic machines pour liquid glass into cavity molds
- Packaging – again, robotic arms powered bt air will safely and neatly package the bottles into each box for delivery
- Sealing – air-powered machines will extract all the air from the empty portion of the bottle before another places a lid on the bottle
For aircraft, tanks, and other aerospace and military pieces of equipment, two-stage compressors are used in all stages of their assembly. Two-stage air compressors allow manufacturers of aircraft, helicopters, rockets, and other military vehicles to be produced with speed and precision for maximum efficiency. Without compressed air, manufacturers could not meet such fast production demands. Most notably the following processes:
- Assembling – pneumatic tools are used to fasten each part together in a methodical order along a conveyor system
- Cutting – raw materials are cut into specific shapes and formed into cavities. Without compressed air or a dual-stage air compressor this work would be very difficult
- Fastening – compressed air and pneumatic tools are used to bolt or rivet parts into place for maximum strength at high altitudes
- Finishing – a mixture of compressed air powered sanders, blowers, painters and dryers handle all the finishing touches on military vehicles
- Shaping – pneumatic sawing tools are used to cut raw edges on given designs to ensure they are the exact desired measurements
A final notable use for both types of air compressors is food preparation and packaging. It’s possible to use either a single-stage air compressor or a two-stage air compressor depending on the scope and magnitude of the operation.
Within an in-house kitchen of a supermarket or a bakery, you will be able to accomplish everything with a one-stage air compressor. In terms of mass productions in a factory, you will need to use a two-stage air compressor. Single-stage air compressors are ideal can be moved to different locations, if necessary, to meet the demands of a given day’s tasks. Compressed air is typically used in the food industry to drive the following processes:
- Cooling – air-powered tools can aid in the cooling down of food to suitable temperatures for packaging
- Chopping – for example, compressed air used with specially designed cutting tools will give certain potato chips their ridges
- Cleaning – an air compressor with blowing tools will allow you to blast air to remove dirt, moisture or air-bound impurities in containers
- Frosting – air-powered tools are used to apply icing as well as injecting fillings into pastries
- Powdering – air-powered equipment usually does the powdering for mass-produced doughnuts and cookies
Which is Better? Single-Stage or Two-Stage?
Your choice between a single-stage compressor or a two-stage compressor typically depends on the size and nature of your projects. In short, a single-stage compressor is better for small-scale projects and personal use while a two-stage air compressor is better for industrial use.
Single-stage air compressors have one cylinder with one piston stroke for each revolution of compressed air. These units are relatively quiet and are ideal for working in small environments like your home, garage, or workshop. Single-stage are compressors generally cost less, weigh less and their electric models draw fewer amps. Two-stage air compressors are typically more efficient, run cooler and deliver more CFM.
If you’re looking to operate multiple tools simultaneously, then the most important specification for you is the compressor’s CFM, the operating capacity of the compressor. Your compressor must exceed the demands of all your tools and be able to run continuously, which is why two-stage air compressors are better for this sort of work.
Which is More Reliable? Single-Stage or Two-Stage?
That’s not all right? A major difference between a single-stage compressor and dual-stage air compressors is that the latter is suited to ongoing, or continuous, applications, while the former is primarily designed for intermittent use. So, determining which type of compressor is more reliable will totally depend on what jobs you intend to do with your compressor.
I’ll dig deeper into each compressor’s uses further down this article, but for now, a single-stage compressor is typically suited to handling jobs like powering your air tools in your garage or even some cooking equipment in the kitchen. If you were to require a compressor for heavy machinery and other factory applications, then it’s quite easy to say that single-stage compressors won’t be that reliable, or as reliable as a two-stage unit.
Why is this you might wonder? Well, the parts in single-stage models are a lot large and more prone to condensation. Let alone the fact they’re not built with a 100% duty cycle (continuous use). Compared to their single-stage counterparts, dual-stage air compressors are capable of providing the large amounts of CFM needed to handle masses of air-powered tools and therefore, they are more suited to applications that include painting and sanding.
Which is More Expensive? Single-Stage or Two-Stage?
Due to the additional stage in two-stage air compressors, they tend to be more expensive than their single-stage counterparts due to the additional parts needed. However, these parts are smaller and typically require less frequent maintenance than the parts in single-stage compressors. And so, in the long run, a two-stage compressor may actually become less expensive and a far better investment.
In terms of factory settings, where multiple pneumatic tools are being powered simultaneously. You need two-stage air compressors because they can offer optimal CFM for your multiple high-powered pieces of equipment. A single-stage compressor within a factory setting would certainly not suffice.
You would more than likely need multiple single-stage compressors available to handle your applications, which would increase your operating costs. Without a doubt, in factory settings, the upfront cost of two-stage air compressors will save you money in the long run. Two-stage compressors offer better value and reliability for continuous use applications, such as auto repair and manufacturing.
Below are a couple of examples of a Singe-Stage compressor and a two-stage compressor readily available on Amazon. It is clear to see the price variation from the single-stage to the two-stage compressor, and also the CFM capabilities of each: with the single-stage offering 5 CFM and the two-stage 24 CFM! Yes, you pay over 4 times the price, but you also get 4 times the CFM capability!
CFM @ 90PSI : 5 CFM
Maximum Pressure: 135 PSI
Duty Cycle: 100%
CFM @ 90PSI : 24 CFM
Maximum Pressure: 175 PSI
Duty Cycle: 100%
FAQs (Frequently Asked Questions)
2 stage compressors hold the advantage of being able to provide greater CFM capabilities than 1 stage compressors as well as being able to operate at far higher pressures. This extra capability allows them to power multiple tools at once, continuously. Typically 2 stage compressors are suited to industrial settings and factories, while 1 stage compressors are suitable for use at home with tools that require less than 100 PSI.
Inspect the configuration of the pump, this will depict the obvious differences. If your compressor is 2 stage, it will suck air into one piston and send it to another piston. If your compressor is single-stage then air will be sucked into one piston and then sent directly to the storage tank!
You can easily tell how many stages your compressor has based on the size of the air cylinders. All cylinders will be the same size on single-stage compressors. On the contrary, dual-stage or multi-stage compressors will have a second piston shorter than the first or progressively smaller cylinders, linked with a cooling tube to bring the temperature down before the second round of compression on two-stage compressors.
Other Types of Compressors Reading
The types of compressors aren’t limited just to single or two-stage compressors, there are many different variations of design. Visit our pages below for more information!
- Reciprocating Air Compressors Explained
- Rotary Vane Compressors Explained
- Rotary Compressors Explained
- Centrifugal Compressors Explained
- Axial Flow Compressors Explained
- Types Of Air Compressors – Air Compressor Types & Applications
If you have any questions regarding two-stage air compressors vs single-stage air compressors, please leave a comment below, with a photo if applicable, so that someone can help you!