Working with
Compressed Air

Working With Compressed Air

Compressed air, commonly referred to as the fourth utility, is the energy of choice to power a great variety of applications and processes. Compressed air is vital to the productivity of industries around the globe. Learn more about working with compressed air.

Why Use Compressed Air


The raw material for compressed air, i.e., atmospheric air, is freely available everywhere on the planet. Compressed air is versatile and adaptable; it easily flows through pipes and valves, quickly filling a space. It can be compressed to higher pressures, stored as energy, and used to perform many types of work processes. Compressed air is considered a power source like gas, electricity, and water, and is often referred to as the fourth utility.

Versatile Utility

Compressed air is versatile.

  • Compressed air can be easily stored for its intended purpose, using storage tanks or bottles located in places where no other power is available or practical.
  • Equipment operated by compressed air can function at extreme temperatures.
  • Air tools are ideal for dirty applications, such as in steel mills and foundries, where destructive operating conditions would challenge the reliability of electric powered equipment.

Cost Effective

Compressed air can be managed to be cost-effective.

  • Unlike the other utilities, compressed air is generated on-site, giving users much more control over its usage, quality, and generation cost.
  • Compressed air usage can be easily monitored and controlled to deliver reliability, productivity, and efficiency.


Compressed air is safe.

  • Compressed air is safe to discharge back into atmosphere. Leaks are not hazardous.
  • Compressed air is safe to use in environments that are wet, explosive, or combustible where an electric device could present a safety concern.
  • Compressed air can have a high degree of cleanliness, essential for applications where quality, hygiene and safety are imperative.
  • Air tools are often much lighter and operate significantly cooler than their equivalently powered electrical counterparts, making air tools easier and safer to operate.

Compressed air is present across just about every industry and it is used for many functions; from running huge equipment to powering simple air tools. Compressed air is a valuable utility and is a safe power source when used properly. As with any other energy-carrying power source, compressed air should be regarded with caution and handled with care to avoid accidents and user injury.

The following standards and regulations should be consulted when using compressed air:

  • ANSI/CAGI B19.1, Safety Standard for Air Compressor Systems
  • CAGI B186.1, Safety Code for Portable Air Tools
  • ISO 11148 Series
  • OSHA regulations

Cost of Compressed Air

Although air is free, the cost to compress, treat, and distribute compressed air is significant. It takes approximately 8 horsepower worth of electrical energy to produce 1 horsepower worth of compressed air energy. Despite this inefficient conversion of energy, compressed air usage surpasses both electric and hydraulic power sources for industry, largely based upon the prominent benefits of using compressed air. The efficiency focus of compressed air becomes that of producing it as inexpensively as possible and not wasting it.

The most expensive component in the total cost of ownership of a compressed air system is the energy required to produce and deliver an uninterrupted supply of clean, dry compressed air at a stable pressure to every application in the system. Over the lifespan of a typical compressor, energy typically costs several times more than the purchase price of the compressor. This fact makes it a wise decision to purchase the most energy efficient equipment available and to operate it in a manner so it delivers its maximum efficiency. The bottom line is, maximizing energy efficiency saves money.

Many manufacturers overlooked compressed air costs for years when power was inexpensive, but as energy costs have increased significantly, it is imperative that facilities become educated about how important the total cost of ownership of their compressed air system is to saving money. For example: A manufacturer operates a 200 hp compressor, 24 hours a day, 365 days a year. When the manufacturer installed the compressor, energy cost was $0.03 per kWh. The annual electric cost to operate that compressor was $41,273. As the average electricity rate has risen to $0.10 per kWh, the electric cost to operate that same compressor under the same conditions is now $137,578. As energy costs have increased, they have garnered the attention of facility managers, who are charged with finding new solutions to reduce costs.

Since compressed air is a very expensive utility, wasting it is to be avoided. There are three main ways in which compressed air is wasted in a compressed air system: leaks, artificial demand, and inappropriate usage.

Leaks are the most obvious source of compressed air waste. Air under pressure flows to areas of lower pressure. Any opening to the atmosphere that is large enough to allow an air molecule to pass through it will become a leak. And the amount of air that flows through the opening increases as the pressure differential between the compressed air and the atmosphere increases. Aging, rusted piping with threaded fittings presents the perfect opportunity for leaks. Cheap, ill-fitting quick disconnect fittings are a major source of leaks. Plastic or rubber tubing that feeds air to a component frequently becomes cracked or split due to aging, vibration, or chemical attack and leaks – often silently. In fact, approximately 80 percent of air leaks are not audible, and they go unnoticed and unrepaired. A quarter-inch air leak at 100 psi will waste 104 cfm, and consume approximately 25 hp.

Energy Cost ($/year) = motor bhp x .746 x hours of operation (per year) x electric rate ($/kWh) / motor efficiency

Using the above energy cost formula, that quarter-inch leak will waste more than $17,000 a year in a system where the leak flows continuously for 8,760 hours, the power cost is $0.10/kWh, and the compressor drive motor has a 94% efficiency rating.

Estimates indicate that poorly designed and maintained compressed air systems in the United States account for up to $3.2 billion in wasted utility payments every year. A conservative estimate is that the average leak rate in United States manufacturing facilities is as high as 30%. Compressed air leaks account for a significant amount of wasted electricity and provide the greatest opportunity for energy savings. A careful examination of the compressed air system in a facility will likely reveal numerous leaks. Since a majority of these leaks are not audible, it is critical that the facility utilizes the latest technology in leak detection to locate leaks so that they can be repaired. Ultra-sonic leak detection can be provided through your compressed air supplier or other companies that specialize in this field.

Artificial demand is another source of wasted compressed air and it is based on the fact that any air consuming device, leaks included, will consume more air as the pressure differential between the inlet and discharge of the device increases. The reverse is also true. For example, if a pneumatic cylinder requires 1 cubic foot of air @ 80 psig to complete its stroke, that same operation will consume 1.21 cubic feet of air when the system pressure is increased to 100 psig. Accordingly, artificial demand is the increased consumption of compressed air that is a result of operating at a higher pressure than is required to obtain the full function of the air operated device. By operating a compressed air system at the lowest pressure possible, the facility can keep the wasteful artificial demand to a minimum.

Inappropriate usage is just that, using expensive compressed air to perform work that is more efficiently performed by some other source of power. Using compressed air to continuously blow loose debris from underneath a piece of machinery is an example of an inappropriate usage of compressed air. That cleaning task can be performed with a broom, an electric leaf blower, a fan, or a positive displacement blowerb – all of which are significantly more economical than using compressed air. Inappropriate applications should be identified and replaced with alternate, more economical sources of power.

Compressed air is an expensive utility to produce and wasting it should be avoided at all times. The best way to begin a compressed air cost reduction project is have a trained, compressed air professional perform a system assessment on the entire compressed air system. This assessment will establish the true cost of compressed air for the facility, identify leak sources and inappropriate applications, and calculate the artificial demand of the system. Armed with this data the facility can implement a cost reduction project that addresses the three areas (leaks, artificial demand, and inappropriate usage) that impact system efficiency and total cost of operation.

Optimizing for Efficiency, Profitability, and Sustainability

Using compressed air as a source of energy can raise several questions with respect to efficiency, sustainability, heat recovery, and much more. Below are 8 best practices that users of compressed air should understand thoroughly. These best practices will guide the user toward optimizing their system to deliver maximum reliability, efficiency, and sustainability. CAGI has developed technical briefs, case studies, and FAQs to address these best practices, which can be downloaded for easy reference and to share with colleagues.

Whether you are increasing the demand of a current system or designing a new system, your three parameters of importance are demand (cfm), pressure (psig), and air quality. Proper sizing and selection of compressed air equipment requires that these three parameters be clearly defined before equipment decisions can be made.

Determining system demand (cfm) when increasing the cfm of an existing system can be accomplished by first measuring the existing system demand by performing a compressed air system assessment utilizing a trained compressed air professional. This baseline demand will reveal the maximum-, average-, and minimum demands of the system. Once the baseline demand profile is established, adding additional capacity into the system becomes an exercise in summing the cfm requirements for the additional applications. Baseline cfm plus the additional required cfm becomes the new demand around which additional equipment can be sized. At this point it is wise to consider future expansion plans and if you believe that your manufacturing activity could ramp up or down during the coming years, these variables need to be considered.

When determining the demand for a new system, the task becomes a tedious one of summing the full-load cfm demand of all applications to which is applied a usage factor; the percentage of time the device operates during a particular time period. Most applications are intermittent users of compressed air, and their average demand is often much less than their full-load cfm at which they are rated. Again, once system demand is calculated, it is wise to consider future expansion plans.

System pressure requirement is determined by the highest pressure required by any application to be able to operate reliably and efficiently. Expending initial investment up front to select devices that operate at lower psig requirements will harvest significant energy savings over the life of the compressed air system as the compressors will be able to operate at reduced pressure – consuming less energy.

Air quality is determined both by the application and the customer. Applications that require compressed air to come into direct contact with the finished product will have more strict air quality standards than will applications where the air does not contact the product. For example, pharmaceutical and food applications will have different air quality standards than a metal stamping operation. Many applications have specific air quality specifications required for their proper operation. These specifications limit the amount of solid particles, water, and oil that the compressed air can contain. The more stringent the air quality is, the more it costs to achieve that higher level of quality. For this reason, a lower air quality might be specified for “plant air,” which constitutes the majority of the system demand, and for those applications that require higher quality air, this demand might be met with additional air treatment processes.

Once cfm, psig, and air quality have been determined, the next decision in sizing a compressed air system is selecting the type and number of compressors. Three distinct technologies are available: rotary, reciprocating, and centrifugal. Each technology has its advantages and disadvantages, and these characteristics must be evaluated with regard to the specific application that the air system serves. Small, intermittent applications often are best served with reciprocating technology where continuous applications are better served by rotary or centrifugal technologies. Once the type of compressor is selected, it is important to determine how many compressors will be used to supply the system demand.

It is good design practice to build redundancy into any compressed air system where the failure of a compressor could potentially shut down the operation. To accomplish this redundancy, you can install two equally sized compressors, each one rated to deliver 100% of the system demand. This system works best when the system demand is rather consistent with little variations throughout the shifts. However, if demand varies significantly amongst shifts, it might result in one, large compressor being deeply part loaded, which is not only inefficient, but could also be detrimental to the life of the compressor. In situations where system demand is variable, a solution is to install three compressors each rated at 50% of total maximum system demand. This arrangement allows for two compressors to handle the peak demand with one compressor in backup mode. At minimum demand, only one, smaller compressor will operate in a part-load, trim position, which greatly improves part load efficiency over operating one large compressor at the same part load demand. Additional part load efficiency can be gained if one of the three compressors is a variable speed design and is always set to operate as the trim compressor. A similar design and redundancy approach should be followed for the selection of the air treatment equipment in the system.

A thorough evaluation of your process with a qualified compressed air professional is the best way to ensure that your compressed air equipment is sized, installed, and is operating correctly to provide you with the highest efficiency, reliability, and productivity that you require from your compressed air system.

View Technical Brief - Sizing Compressed Air Equipment

View Case Study - Sizing

View FAQs – Sizing for Compressed Air Supply

Pressure drop within a compressed air system is unavoidable since air is a fluid and as a fluid flows through a pipe, the pressure differential between two points within the fluid decreases. Pressure drop requires the compressor to operate at a higher pressure to overcome the pressure drop, created through the transmission piping, so that the end user receives the amount of pressure it requires to function properly and efficiently. Higher compressor discharge pressure requires more energy. In fact, for every 2 psig of excess operating pressure, the air compressor power consumption increases by approximately 1%. For this reason, reducing pressure drop to its minimum is essential for optimizing the efficiency of any compressed air system. A well-designed compressed air system should have no more than a 10% pressure drop between the compressor discharge and any point of use. If your system exceeds this, then it is performing poorly and using excessive energy.

Many factors affect the amount of pressure drop that a compressed air system experiences. Such factors include pipe diameter and internal pipe surface roughness, air speed, and the number of fittings, valves, and elbows that the air must flow through. Additionally, undersized or dirty air treatment equipment, especially filters, create restrictions to flow and create significant pressure drops within the system.

Understanding how pressure drop is created allows an experienced air system designer to minimize the pressure drop within a compressed air system. Therefore, it is always a prudent investment in system efficiency to have an air system assessment performed on your system by a trained compressor expert; someone who understands pressure drop and can make recommendations that will keep and maintain pressure drop to its absolute minimum. Such a system assessment will provide valuable data that will allow you to make informed decisions regarding important issues that affect system reliability, efficiency, and productivity, as follows:

  • Is the compressed air distribution system optimized for maximum efficiency?
  • Has system efficiency and reliability been negatively affected by improper maintenance?
  • How much CFM-wasting artificial demand exists from leaks and inefficient use of compressed air?
  • Is there proper storage volume to maintain proper system pressure?
  • Are the correct air system components in place and are they designed to work together efficiently to produce the air pressure and air quality needed for the operation?

All components within a compressed air system produce pressure drops. Accordingly, it is important to address pressure drop on a system-wide basis. Contact your local compressed air system expert who can review your complete compressed air system and offer solutions for keeping expensive, energy-robbing pressure drops to their minimum.

View Technical Brief - Pressure Drop

View Case Study - Pressure Drop

View FAQs - Pressure Drop

In the past, the piping network in a compressed air system was an afterthought, and little consideration was given to the type of compressed air distribution system installed in the facility. At one time, it was estimated that more than 50% of manufacturers did not have an accurate diagram of their compressed air distribution system. Now, in an operating environment of escalating energy costs with universal importance upon profitability and sustainability, more companies understand that their compressed air distribution piping is an integral component in the design of an efficient and reliable compressed air system.

Think of your compressed air like any other commodity, such as food. You can produce the best food in the world, but without an effective distribution system, it cannot get where it needs to be, either on time or in the best possible condition. The highest quality compressed air means nothing if it is distributed through a piping system that is rusty, corroded, contaminated by water, or choked with excessive pressure drops. The design of the distribution system plays a critical role in ensuring the reliable and efficient delivery of clean, dry compressed air at a consistent pressure to all applications within the system.

The science of compressed air distribution systems has evolved over the years. Piping systems are available that virtually eliminate the multitude of potential leak sources that legacy piping systems create. Eliminating leaks saves money. For example, in a 100-psig system that operates 8760 hours, per year at an energy cost of $0.10 per kWh, a 1/16” leak wastes 6.49 cfm and costs $982. A 1/8” leak wastes 26 cfm and costs $3,935. Modern compressed air piping systems offer low pressure drop piping materials and fittings and allow for easy modifications such as adding new drops or creating new loops. Such versatility greatly improves the overall efficiency of the compressed air system.

The best way to understand the significant effect that your compressed air distribution system has upon the overall reliability and efficiency of your compressed air system is to hire a trained compressor expert to perform a system assessment at your facility. This assessment will provide the data that is required for you to make intelligent decisions regarding all aspects of your compressed air system.

View Technical Brief - Distribution Piping Network

View Case Study - Piping and Distribution

View FAQs - Distribution Piping Network

“What's new in compressed air?” is a question that is asked often by Plant Managers who understand that the efficiency and reliability of their compressed air system plays a significant role in the profitability of their total operation. When the answer to that question is, “Variable speed drive compressors,” the Plant Manager often responds, “VSDs have been around for ages.” And it's true, they have, but there have been significant advances in VSD technology since their introduction in the year 2000. VSD compressors are similar to light bulbs and automobiles when you consider the improvements that these now common-place items have undergone in recent years.

The efficiency of modern light bulbs has increased exponentially. Despite this fact, statistics indicate that up to 65% of American homes have not installed energy-efficient light bulbs even though the extra cost of the modern light bulb would have a payback of several months. While VSD drives are suitable for approximately 70% of all compressor applications, it is estimated that only half of the VSD-suitable applications actually have VSD compressors installed. Although VSD technology has been around for years, providing up to a 35% reduction in energy costs, many US manufacturers are still deciding if they should adopt this technology.

Considering automobiles, it’s true that the Ford Focus has been around for years, but the current model looks and performs very differently from the original model. The base technologies used are still the same, but they are constantly being improved. The same is true with VSD compressors. Perhaps the VSD manufacturer and model have been around for many years, but the performance gets better and better as VSD technology becomes more robust, reliable, easily installed, and more efficient. Accordingly, if you have a legacy VSD machine today, or if you had a negative experience with VSD compressors in the past, you should always be open to looking at the latest advancements and innovations to the established, VSD compressor technology.

View Technical Brief - Variable Speed Drive

View Case Study - Variable Speed Drive

View FAQs - Variable Speed Drive

An air system control unit is the quarterback of your compressed air system; calling the plays, spotting the dangers, and ensuring everybody knows what to do. Based on the size and number of components in your system, a good system controller will maximize system efficiency, reliability, and performance by managing the proper sequencing of the compressors and regulating the variable speed drive, if applicable. Because the system is now automatically regulated, human intervention is rarely needed. Experience has shown that intervention by untrained individuals, no matter how helpful their intentions, can adversely affect the overall performance of the compressed air network.

There are 168 hours in a week, but most compressed air systems operate at or near full capacity on average between 36% to 60% of the time, or 60 to 100 hours per week. Accordingly, compressors frequently run for long periods at less than their full load capacity and depending upon the control system that the compressor utilizes to match its output to the system demand, such part load operation can by extremely inefficient. A good system controller will quickly monitor the rate of change in demand within the system and manage the type and number of compressors that are best suited to deliver integrity and efficiency. Actions as simple as turning compressors off during the evenings and weekends could reduce energy bills up to 20%.

A controller will often be the first alert when there is a problem. Such an early alert provides sufficient warning to be able to fix the issue before it gets out of control. Depending upon the sophistication of the controller, it can manage many other components within the compressed air system in addition to the compressors. It can manage flow control valves in different parts of the system to control specific zone pressures. It can control air quality by shutting down or starting air dryers through a system-integrated dew point monitor. Such control keeps the system operating efficiently, reliably, and with stable pressures.

System controls should be added only after a system assessment, by a trained air system professional, has been performed on the existing system. Only then can clear and achievable data-based objectives be discussed and implemented to achieve the desired level of system efficiency, reliability, and productivity. As compressor numbers exceed three, the need for a system controller becomes critical to the efficient functioning of any compressed air system.

View Technical Brief - System Controls for Industrial Compressed Air Systems

View Case Study - System Controls

View FAQs - System Controls

It's simple physics that compressing air creates heat, and in great quantities. Nearly 96% of the electrical energy consumed by an industrial air compressor is converted into heat, and as much as 90% of that wasted heat can be recovered for use within the facility. If you use hot water, hot air, or steam in your plant, then a heat recovery unit would probably be to your advantage. For example, heat recovered from the compression process can produce hot water for washrooms or HVAC heating into a workspace, warehouse, loading dock, or entryway. By recovering this heat, you nearly double the value of the amount of energy required to operate the compressor, effectively receiving an energy rebate. Harvesting the heat from the compression process can significantly lower energy costs and generate substantial savings.

Like variable speed drive technology, heat recovery systems have improved greatly over the years. In many cases, they are available as a retrofit package for a compressor you already have. The first step to determining how much heat you can harvest from your existing compressed air system is to contact a trained compressor expert who can perform a compressed air system assessment. The assessment will ensure that your current system is functioning as designed. Then, based on the age of your compressor and its components, the results of the assessment will give you the input needed to determine whether your system provides the opportunity to harvest the heat of compression to achieve significant energy savings.

Put the heat from your compressor system to work for you and investigate the benefits of a heat recovery system for your facility.

View Technical Brief - Heat Recovery from Industrial Compressed Air Systems

View Case Study - Heat Recovery

View FAQs - Heat Recovery

The Harvard Business Review published an article on sustainability in which was stated, “It’s a common misperception that responsible or sustainable investments are all in the hug yourself, warm feeling, good intention category, the inevitable consequence of which is diminished investment return. Nothing could be further from the truth." The article went on to report that companies that use less energy, less water, and create less waste in generating a unit of revenue tend to produce higher investment returns than their less resource-efficient competitors.

There are multiple examples of activities and technologies which can make your plant more sustainable, a few of which are: leak detection and prevention, heat recovery, control systems, improved maintenance, and variable speed drives. Sustainability is more than energy savings. It involves the total impact of your compressed air system upon the environment. Through a sustainability focus that optimizes the efficiency of the compressor and harvests the significant quantity of the heat of compression, it is possible to achieve annual energy cost savings of over $30,000 as well as a reduced CO2 output by about 269 metric tons with a 200 hp air compressor. 269 metric tons is roughly equivalent to the mass of four city buses. Just imagine the difference you could make to both your energy costs and to the environment when you take a sustainability focus to your compressed air system. Sustainability is much easier and more significant than you might think.

In summary, sustainability is good for business, good for our planet, and vital to the well-being of future generations, both economically and socially.

View Technical Brief - Sustainability

View Case Study - Sustainability

View FAQs - Sustainability

Case Studies

The CAGI case studies demonstrate the solutions implemented to address challenges faced by CAGI customers that increased the efficiency of their compressed air systems resulting in substantial cost savings. Each case study includes the problem, desired state, root cause, solutions considered, solutions implemented and outcome:

A reliable source of clean, dry, compressed air is fundamental to the operation of modern, sophisticated machinery in the highly automated plants found throughout industry. As with most industrial machinery, a compressor runs more efficiently when properly maintained. Proper compressor maintenance cuts energy costs around 1% and helps prevent unscheduled breakdowns that result in costly downtime and lost production. Proper maintenance provides any compressed air system with increased reliability, efficiency, productivity, and ultimately, increased profitability.

In the past, management focus was strictly upon production and the function of maintenance departments was to quickly fix broken equipment so that production could continue. This is what is known as a “break-fix” maintenance strategy. Such a strategy was effective when maintenance departments had sufficient staff and equipment repairs could be handled by maintenance personal with basic mechanical skills and basic tools. As maintenance staffs dwindled in number and equipment became more sophisticated with modern electronic controls, management teams recognize that the break-fix strategy of maintenance was unsustainable. Proper maintenance is designed to prevent or greatly reduce the incidences of break-fix situations, which usually lead to expensive shutdowns, costly after-hour emergency repairs, and expensive equipment rental charges. Described below are two types of proper maintenance approaches that are used to maintain compressed air equipment.

Preventative maintenance became popular when manufacturers realized that the usual break-fix mentality towards keeping production running was making these manufacturers uncompetitive in a growing world economy. Preventative maintenance is a strategy for caring for equipment that utilizes planned maintenance procedures that are designed to maintain the reliability of equipment based upon its normal, expected wear and tear. Although preventative maintenance does not eliminate failures, it reduces the number and magnitude of the failure. Preventative maintenance allows for major repairs to be scheduled for planned outages. With preventative maintenance, equipment is maintained with a frequency that has been determined to be the proper interval that is required to keep air system equipment in optimum operating condition, ensuring maximum efficiency. These service interval frequencies are established based upon years of experience in equipment design, field-testing, reliability, and operation over a variety of differing operating environments.

Under a preventative maintenance program, compressed air equipment is serviced regularly according to a schedule, usually based upon run-time hours. Provided that the maintenance schedule is followed, and quality components and fluids are used, a preventative maintenance plan can be highly successful in increasing the longevity of compressed air equipment, reducing the incidence of failures, as well as increasing the efficiency of the equipment. The goals of a preventive maintenance program include an increase in equipment uptime, a reduction in the number and duration of planned outages, a reduction in costly catastrophic failures, and perpetuating the productivity of the equipment as it was originally designed - all of which increases the reliability, productivity, and efficiency of the operation.

Benefits of Preventive Maintenance

  • Maintain productivity by increasing equipment reliability
  • Reduce the number of unscheduled, costly, break-fix incidents
  • Reduce repair cost versus break-fix cost
  • Reduce product scrap and re-work costs
  • Provide more efficient control over spare parts and maintenance scheduling

Predictive maintenance has been developed to complement the scheduled maintenance strategy inherent to preventative maintenance programs. Predictive maintenance focuses upon proactively identifying equipment issues before they become catastrophic failure events. Such proactive monitoring allows for scheduling repairs and maintenance so as not to disrupt normal production. Predictive maintenance employs the use of modern instruments, tools, and technologies to gather accurate data regarding machinery conditions without disrupting normal production operations. Such data is then used to make informed decisions as to the condition of the equipment and to prescribe the proper maintenance procedures required to bring its performance up to the desired level.

Forming the backbone of a predictive maintenance strategy are modern, condition monitoring technologies that provide reliable and valid data regarding the functional health of the components within a piece of equipment. Condition monitoring identifies changes in the actual operating performance of a component when compared to the baseline performance of the component over time. By analyzing the magnitude of the change, a technician can accurately predict the time-to-failure for a component, allowing it to be repaired or replaced before the condition escalates into a catastrophic failure. As a result, equipment uptime is maximized, planned maintenance can be scheduled so as not to interfere with production, and profitability is increased. Condition monitoring technology is capable of identifying a wide range of issues that affect the reliability and performance of equipment. Issues such as misalignment, imbalance of rotating assemblies, gear wear, deteriorating bearings, improper lubrication, and electrical issues are all able to be identified long before they present a failure mode.

Benefits of Predictive Maintenance

Proper record keeping is essential to a successful predictive maintenance program. Performance change over time is key to accurate predictive maintenance no matter what condition is being monitored. Such records of performance degradation over time provide the data that management requires to justify the expense of additional budget for maintenance. Companies that adopt predictive maintenance programs report the following benefits:

  • Avoid disruptive and costly break-fix events
  • Increase productivity
  • Minimize equipment degradation which reduces scrap and rework
  • Provide accurate documentation for justification of maintenance budgets

Predictive Maintenance Technologies

Manufacturing processes and equipment are being subjected to increased stress as companies demand additional capacity, efficiency, and productivity. Such stress forces equipment to perform in many cases up to and beyond its design limitation. Accordingly, the diagnostic capabilities of advanced, condition monitoring technologies have become critical tools in allowing predictive maintenance strategies to improve the reliability, efficiency, and productivity of industrial operations worldwide. Below are some of the most-used condition monitoring technologies employed in a predictive maintenance program for air compressors:

Lubrication/Oil Analysis

Surveys have shown that lubrication is the culprit in over 50% of all industrial breakdowns; be it lack of lubrication, over-lubrication, contaminated lubricant, or the use of the wrong lubricant for the job. Oil analysis, one of the oldest condition monitoring tools, is used to define the following three basic conditions:

  1. Condition of the oil
  2. Condition of the lubrication system
  3. The condition of the machine itself

When performed and trended over time, oil analysis can identify improperly performed maintenance, degradation of metal wearing components, and degraded lubricant life as a result of excessive heat, contamination, or the addition of an improper lubricant.

Machine Condition Monitoring

Sound analysis is one of the oldest and most commonly used technologies for detecting equipment issues. It works by detecting sounds that are abnormal over time. Sound abnormalities are best noticed when sound analysis is performed on a regular basis, preferably daily. Once an abnormal sound is audible, it indicates an advancing issue that requires maintenance attention.

Predictive maintenance programs for compressors rely heavily upon vibration analysis to determine the operating condition of rotating equipment. Vibration, trended over time, can identify potential problems before they cause serious failures and unscheduled downtime. Vibration analysis is commonly used to detect failing bearings, excessive gear backlash, mechanical looseness, and worn or broken gears. It can also identify component misalignment or rotor imbalance before they can cause bearing, shaft, or coupling deterioration.

Using an ultrasonic analyzer, a technician can locate and quantify compressed air leaks according to their size. This information is essential for maintaining equipment and system leak rates at their absolute minimum.

Thermographic and infrared analysis provides visual images that represent variations in the surface temperature of components. Mechanical and electrical issues frequently present themselves as increases in temperature as a result of mechanical friction or failing electrical connections.

To determine which type of maintenance plan is proper for your compressed air system, consult with your compressed air service supplier to receive professional advice as to the most cost effective way to maintain your compressed air system to retain its reliability, longevity, and efficiency.

OEM Parts

Maintenance kits and replacement parts manufactured by the original equipment manufacturer (OEM) of your compressed air equipment offer the best overall performance. OEM parts have design and manufacturing specifications that the manufacturer has determined to best deliver the required performance needed to assure warrantable equipment reliability and functionality. OEM parts are designed to maintain unit efficiency and reliability. Furthermore, just as OEMs are continually upgrading the performance and reliability of their equipment, so too are they improving the performance of the components that go into the manufacturing of the equipment. This particularly includes the consumable components such as fluids and filters. By using OEM components, you are assured that you are installing parts with the most current form-fit-and function. Generic parts do not provide this assurance and the use of generic, will-fit, aftermarket components can significantly decrease the performance and reliability of the equipment, and in many cases, the use of generic parts may void manufacturer warranties. The money you save by purchasing generic parts is often the most expensive money you will ever save.

Manufacturers, equipment distributors, or sales representatives of most compressed air and gas equipment may provide service agreements for new or existing equipment. Depending on the extent of responsibilities outlined in the agreement, the services provided could allow facility maintenance personnel to focus all of their expertise and time entirely upon the equipment needs of their core business.

Qualified service technicians provide expert knowledge on air system equipment. From factory start-up to long term maintenance, they ensure that equipment is installed as designed and will operate efficiently and reliably with other system components. Trained service technicians receive extensive industry and product specific training that non-industry technicians do not.

Many manufacturers also provide specialized training for customer maintenance personnel, which may be held at dedicated training facilities or at a customer's site. Hands-on training and classroom instruction increase the confidence of maintenance personnel in dealing with the often arcane issues encountered with maintaining and managing a compressed air system.

View Technical Brief

View Case Study

View FAQs


The manufacture of compressors and compressed air equipment is a large and essential industry that provides a true power source for innovative solutions and applications. From the standpoint of applications, compressed air and gas may be divided into power, process, and control.

Power Service Applications – Power service includes those applications in which air is used either to produce motion or to exert a force, or both. Examples are linear actuators, pneumatic tools, clamping devices, or air lifts, and pneumatic conveyors.

Process Service Applications – Process service is defined as any application in which air or other gas enters into a process itself. Examples are combustion, liquefaction and separation of gas mixtures into components, hydrogenation of oils, refrigeration, aeration to support biological processes, and dehydration of foods.

Control Applications – Control applications are those in which air or gas triggers, starts, stops, modulates, or otherwise directs machines or processes. Control applications occur throughout power and process use. Some steady-flow process plants are virtually completely automatic. Detroit-style, batch-type manufacturing may be highly automatic and pneumatic controls have special attributes that make them ideal for many situations. These include control of pneumatic machines or control with explosion-proof requirements.

Electronics Application


  • Direct production and assembly of circuit boards, wafers, memory chips, LCD panels, etc.
  • Polishing and removing chemical deposits
Electronics Application

Wood Products:

  • Dust collection
  • Pneumatic equipment
Electronics Application

Power Generation:

  • Instrument air
  • Soot blowing
Electronics Application


  • Injection molding
  • Dry bulk solid conveying
Electronics Application

Pharmaceutical Manufacturing:

  • Tablet coating
  • Aeration for oxidation processes (e.g. lactose)
Electronics Application


  • Sandblasting
  • Machining
Electronics Application

Food & Beverage Processing:

  • Filling and capping
  • Fermentation
Electronics Application

Vehicle Services:

  • Pneumatic tools
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Selection Guides

Air Compressor Selection and Application: ¼ HP through 30 HP is a publication to help users understand the basics of compressed air as a power source and to provide initial technical guidance for selecting the right air compressor for specific applications. The central focus is on complete, packaged air compressor units that are most commonly used in sizes 30 horsepower and below. This “light-industrial” range of compressors covers both reciprocating and rotary types which are frequently applied in intermittent duty applications.

Rotary Air Compressor Selection Guide is a publication to help users understand the different positive displacement, rotary compressor technologies so that they can make informed decisions regarding the type of compressed air system they install, operate, and maintain. This guide focuses on rotary screw, sliding vane, and scroll compressors that are driven by electric motors, combustion engines, or PTO drives and are generally applied in continuous duty or process applications.

Compressed Air and Gas Drying is a publication to help users understand why compressed air and gas need to be dried, how to measure moisture content in gas, and what applications require clean, dry air. This guide focuses on the different types of dryers such as refrigerant, desiccant, heat of compression, deliquescent, and membrane, and provides guidance for selecting the right dryer for the application.

The CAGI Blower Selector Program provides characteristics and performance capabilities of the various blower technologies available today. Blower types featured in this interactive on-line tool include positive displacement lobe, helical screw, single-stage and multistage centrifugal, regenerative, and liquid ring. User-friendly air flow performance maps for both pressure and vacuum conditions are featured for each blower type, providing the user the ability to quickly determine the suitability of a specific blower type for a specific application.

Blower Selector Program