There are several types of air compressors, and they each have applications where they excel. However, for industrial air compressor options, only two types are the most common. These are reciprocating and rotary screw air compressors. There are several other varieties or air compressors that are used for unique applications, which can include rotary vane, rotary scroll, rotary tooth, and the list goes on.

Reciprocating Compressors

Piston Compressors

These are some of the most versatile and common air compressors and are typically smaller or less in horsepower. They use one or more pistons to force air into a small space, through a series of valves, increasing its pressure, then discharged out of the pump. Where the air goes next depends on the application. Common discharge destinations include compressed air tanks and compressed air piping.

This type of compressor is best used when an intermittent duty cycle is called for or in relatively low air demand operations. For example, if an air tank needs to be filled every so often instead of constantly, a piston air compressor is usually a good choice. The same goes for situations where you need to be able to emit a burst of compressed air from a hose every so often.

Notably, piston air compressors can be found in everything from home tire fillers to giant natural gas processing plants. When sized appropriately and in the right conditions, a piston reciprocating air compressor should last at least 15 years but in many cases can last decades!

Diaphragm Compressors

These reciprocating compressors use a diaphragm to compress the air or gas instead of a piston. The diaphragm is oscillated to compress and expand the air/gas within a chamber. Since the air or other gas never contacts the lubricated parts of the machine, there is no chance of the gas being contaminated by oil. Because of this, they are preferred when it is essential that contamination does not occur at all. The diaphragm design is typically used in low flow scenarios with increased pressure requirements. The diaphragm design uses compressed air to actuate and create the higher pressure, therefore consumes more air to produce the higher pressure, these must be sized just right and takes a specialist to properly calculate.

Rotary Compressors

When a company needs an industrial air compressor that can handle a constant or fluctuating demand that requires a continuous duty cycle, rotary compressors come to the forefront. These use a variety of means to keep compressed air constantly flowing.

Helical Screw Compressors

These are good choices for applications where you need a constant supply of compressed air. They’re also excellent for various installation scenarios, whether they are fuel (gas or diesel) driven where you’ll need to bring them in on a trailer, such as road building and construction or electric motor driven with power being supplied form a residential/commercial/industrial building.

This type of compressor uses meshing rotors or otherwise know as a female and male interlock, to pull air or other gas into the front of the rotor and compress it as it travels further along the rotor towards the discharge end. The rotors form “cells” that get tighter as they move, and these both create the compression and keep the air/gas from re-expanding before it should. A discharge port on the opposite end screws allows the compressed air to and travel through the treatment to its destination.

Helical screw compressors have some advantages over their reciprocating counterparts. Since there is no on-off action, vibration and noise are reduced. The biggest advantage is that rotary screw air compressors are designed to run nonstop.

Depending on the specific model involved, lubrication can be provided by water or oil. Some models are suitable for applications where oil-free discharge is critical.

Sliding Vane Compressors

When an application requires an industrial air compressor to run in a contaminant-rich environment, these are often the best choice. They use bushings instead of bearings, and they operate at slow speeds compared to the helical screw compressor. In many industries, helical screw compressors have overtaken these despite the benefit, but they are still popular in applications involving natural gas, oil, and other non-air gas compression.

These compressors work via a series of vanes that slip into a rotor. As the pump rotates, the vanes slide along the inside wall of a cavity, bringing air into a large cavity first and then squeezing the molecules into a smaller space thus reducing the available volume and increasing the pressure as it rotates. Motion is from the intake side to the output end, and by the time the air/gas reaches the output side, it is sufficiently compressed.

Centrifugal Compressors

When you need compressed air for a huge facility, you will run into centrifugal compressors. They drive commercial refrigeration applications up to over 100 hp and can also be found in facilities that need up to 20,000 hp of compression power. These aren’t just strong machines; they can handle huge volumes of air – up to 200,000 cfm or more.

As the name implies, centrifugal compressors work by using a spinning impeller to throw gas outwards. The gas arrives in a casing volute, where its speed slows and it tries to expand, thereby increasing its pressure. Multiple stages may be used to achieve the needed pressures.

Axial Compressors

These are the titans of gas compressors. They can deliver from 8,000 to over 13 million cfm and are used in industrial machines. Jet engines use this type of compressor and can achieve even wider cfm ranges.

Like centrifugal compressors, the axial versions first cause the air or other gas to reach a high velocity, and then slow it down to increase its pressure. These compressors use a series of curved blades for the slowing process.

Which Compressors Are the Most Popular?

In most cases, an industrial air compressor that uses a piston or a helical screw will be the best choice for a shop. Few companies need the extreme capabilities of the other types, and both the piston and helical designs are well-tested and economical.

The choice between these types generally boils down to the needed duty cycle. Piston-based compressors are best for intermittent duty and/or lower cfm demand, while helical screw versions can keep the air coming constantly and at a higher volume of CFM.

Other considerations include the need for oil-free air, the harshness of the environment, and whether the machine will be stationary or brought to a job site without power.

Get Our Expert Advice When Choosing Your Next Air Compressor

At Advanced, we can easily advise you on which type of air compressor is best for your application. We’ll ask all the necessary questions and you’ll provide the needed information and within just a simple five-minute phone consultation. There is no need to guess and risk an expensive mistake.

We also offer all other types of air compressor service you may need, including electric motor repair, general air compressor repair or maintenance, air piping or system design, air compressor rental, and all the air compressor parts you need.

Our specialists are certified in all brands of air compressors, so when you call us, you are talking to skilled experts. Contact us at Advanced Air today for all the help you need.

Pneumatic systems need regular maintenance not only to keep working well, but to ensure that tools and accessories attached to them do not get damaged. There are several types of systems that can be based on an industrial air compressor, so the exact types and frequencies of maintenance tasks may vary. One thing that does remain constant is that pneumatic system maintenance is needed. We will provide general guidelines to give you a good starting point for keeping your system in top shape.

1. Check for Leaks

There are many potential sources of leaks and checking them all on a regular basis is one of the keys to keep your system running optimally and not overworking your air compressor. Your industrial air compressor can provide enough power to overcome the loss caused by some leaks, but even small ones will force it to cycle too often. This doesn’t just increase your energy costs, but it also shortens the life of the compressor by forcing it to work harder and more often than it should, which will create higher maintenance and repair frequencies.

You can check for air leaks in a few ways. Using soapy water to coat the outside of suspect seals, pipe joints, and especially the hoses in your compressed air piping, the soap will cause bubbles where air is escaping. In some cases, you can hear leaks. Walk around your facility near any compressed air piping and equipment, and you may hear the hiss of escaping air, if you can hear it it needs to be fixed immediately!

Another practical way to determine if leaks exist, you can shut down your system and keep an eye on the pressure gauge of the tank, if the pressure falls on the gauge when nobody is using air, the air is escaping somehow. In the case that your own leak search doesn’t reveal the culprit, call us at Advanced. We use expert methods to pinpoint which parts are leaking.

2. Lubricate the System

Air compressor pumps and motors and certain accessories need to be lubricated on a regular basis. Be sure to implement routine maintenance and follow manufacturer’s recommendation for timing and lubrication type to avoid expensive system damage.

3. Be Careful Where the Air Compressor Sits

Dust and debris will get sucked into your air compressor and trapped in the filtration so be mindful on where the air compressor are placed. Many things that are often found in these filters are dirt, pollen, dust, lint, even moisture and many more, this will cause your compressor to not work properly and require compressor maintenance more frequently.

4. Change the Filters Regularly

The system’s application will determine how often filters need to be changed. That said, it is important to change them soon enough to prevent them from becoming clogged, or worse, failing and allowing contaminants to proceed through your system.

Filters are found in many places. Look for filters in air lines, inline dryers, and for some machines even oil removing filters. If your system deals with transporting some type of product, look for filters that deal with that substance, too. The frequency of filter changes will depend on the level of contamination they have to filter out, the size of the particulate being removed, and other such factors.

5. Check and Lubricate the Seals

Check all seals regularly so that you quickly spot any that need to be replaced or lubricated. Seals wear out over time, so it’s normal to need to change them out every so often. How long this takes depends on several factors, including the sealing material and general conditions at the seal’s location. If the compressor is leaking oil it is a good indicator that a seal or gasket needs to be replaced.

6. Refill Mist Lubricators

Some systems have mist lubricators, which automatically emit a mist of lubricant onto targeted parts. Make sure these have lubricant, so nothing goes dry unexpectedly.

7. Check and Service the Silencer

Silencers get clogged over time, and when this happens, they must be cleaned or replaced. Check them on a regular basis so that you don’t find out about the problem by the arrival of abnormal operation. Silencers can be considered intake filters that are applied to the inlet side of a pump or can be considered a muffler for a purge process, like on desiccant dryers.

8. Replace Worn or Failing Parts Before They Break Down

Breakdowns happen suddenly, making them impossible to schedule for. They can also incur expensive emergency service calls. To avoid breakdowns, replace worn or suspect failing parts while you still have time to schedule the proper maintenance. This will let you either have a calm, planned downtime for the event, or even set up an air compressor rental to keep your shop running during repairs. A little maintenance spread out can make all the difference.

9. Design or Redesign Systems to be Easy to Maintain

Ease of maintenance doesn’t just save your company man-hours and reduce the level of irritation involved in keeping your system running efficiently, it is also important for ensuring that every part gets maintained appropriately. If it’s a huge hassle to get to a section of the system, that section is likely to be ignored more often than not. Then, it’ll demand attention by breaking down, forcing you to get an air compressor repair that could otherwise have been avoided.

Of course, it’s easiest to design new air systems with maintenance in mind. If you’re completing a system installation, make sure that all system components are easily accessible – including all the compressed air piping. This will do much to ensure that every part on the maintenance checklist is maintained.

If your system is already in place, go over the maintenance checklist yourself to see if it’s possible to safely reach all the components that need to be checked. You may find some parts that are so inaccessible that it’ll be worth it to go ahead and redo the layouts of those areas of your system. The investment will pay for itself by reducing component failures and increasing the efficiency and accuracy of your maintenance crew.

10. Call Advanced Air

If you need air compressor parts for standard preventive maintenance, need electric motor repair, installation or piping needs, or other advanced repairs, or you would simply rather have professional maintenance technicians handle all your air compressor service, contact us at Advanced Air at one of our three locations in North America. We have certified professionals in all aspects of an air compressor system, whether it is electrical, plumbing, installation, service or repair.