Industrial Utility Efficiency

Mattei Rotary Vane Technology Advancing Efficiency and Durability

Compressed Air Best Practices® Magazine interviewed Mr. Bill Kennedy, Global Marketing Manager, Mattei Compressors.

Good morning! Please describe your role at Mattei Compressors.

Good morning. I joined Mattei Compressors in 2008 and have held a variety of product management, marketing and sales management roles. My current responsibility is as Global Marketing Manager. Our marketing team supports all five divisions of the Mattei Group as well as all subsidiaries. I also support the U.S. sales team, led by National Sales Manager Justo Valenzuela, with air compressor energy efficiency comparisons for specific projects.

A modern installation of Mattei rotary vane air compressors.

Can you describe the leadership and structure of the Mattei Group?

Absolutely. The Mattei Group is led by Chief Executive Officer Giulio Contaldi and by Chief Financial Officer Silvia Contaldi. The Mattei Group is organized internationally into these main divisions. 

  1. The Industrial Division provides stationary fixed and variable speed rotary vane air compressors from 2 to 275 hp (1.5 to 200 kW) to the manufacturing and process industries. We sell exclusively through an international network of authorized air compressor distributors to end users.
  2. The Rail and Transportation Division provides long-lasting compressors to the OEM transport industries including train, bus, and electric vehicle manufacturers.
  3. The OEM Air Compressor Division provides air compressor packages to specialized OEM applications. A hallmark of our firm is a compact, lightweight unitized package incorporating all components in the system.
  4. The OEM Gas Compressor Division focuses on biogas and natural gas applications. A major market is feeding fuel to microturbines.
  5. The Aluminum Smelting Air Compressor Division; Within the Americas, the province of Quebec represents the lion’s share of the aluminum smelting global market. These are custom 100 horsepower rotary vane air compressors whose inherent durability is able to withstand a very hostile application with high ambient temperatures, 24/7 year-round operation and a harsh environment. 
  6. The Mattei On-Vehicle Energy (MOVE) Solutions Division provides precision-outfitting of service vans and trucks up to 30 tons in size. Every energy source a truck needs to be self-sufficient including air compressors, power generators and pressure washers. This eliminates the need, for example, for tow-behind portable air compressors.

Pictured are Chief Executive Officer Giulio Contaldi and Chief Financial Officer Silvia Contaldi from Ing. Enea Mattei SpA.


Didn’t Mattei Compressors recently celebrate a 100-year anniversary? Can you provide a brief history?

You are right! We were proud to celebrate, in 2019, the 100-year Centennial of Mattei Compressors.  Founder Enea Mattei  began the business by manufacturing large, water-cooled reciprocating air compressors.  In the 1950’s,  he, saw the potential of and began to develop rotary vane technology.  His goal was to create a product that had the durability and longevity of those large recips while reducing the requirements for cooling water and the expense of minor valve jobs and major piston ring and bearing overhauls, to further reduce lifecycle costs. The business has continued to be privately held since Mr Mattei sold the business to Giulio Contaldi Sr. in 1958.

Much has changed over the decades since the first rotary vane compressors were engineered and marketed.  Raw lamb’s wool air/oil separators gave way to precision engineered borosilicate material that was made into filter cartridges that have improved over the decades to be much more efficient in coalescing oil while retaining low pressure drop.  Fossil derived motor oil and transmission fluids gave way to synthetic lubricants engineered from a variety of base stocks that provide superior lubricity and longevity while reducing friction and lowering input power requirement.

Where does Mattei have operations?

Mattei is headquartered in Vimodrone, in the province of Milan, Italy. Air compressor manufacturing and package assembly is done in Vimodrone, Verdello-Zingonia (province of Bergamo), Baltimore (U.S.), Woking (England). Mattei exports to over 100 countries and manufactures over 6500 air compressors per year. We have 17 global patents and subsidiaries in the U.S., France, U.K., China, Germany and sales representative offices in Spain and Singapore.
Please describe your U.S. operations.

Mattei Compressors, Inc. is headquartered outside Baltimore in Randallstown, Maryland. Established in 1985, Mattei Compressors supports the America’s with inventory warehousing and custom packaging/assembly capabilities. Our team of Regional Managers across the U.S. support OEMs and air compressor distributors. Over the past ten years the business in the U.S. has tripled, driven by the launch of 50-275 horsepower, sound attenuated, fixed and variable speed air compressors. The attention given to energy efficiency of these product lines has driven a strong level of air compressor distributor support.

Depending upon the model, the new Mattei single rotor, variable speed, rotary vane airends turn within a range of 800 to 1800 rpm.


I remember seeing many rotary vane air compressors in the furniture and woodworking plants of Spain, near Alicante. Don’t rotary vane air compressors have a history of reliability and extreme durability?

Yes, they are known for their reliability and durability – even when the coolers are obstructed with wood chips! Mr. Mattei’s, single-rotor vane compressor was engineered using the same materials of construction for the rotor, the stator and the vanes or blades. This compatibility is what drove the vision to eliminate wear from the compression process in making his compressors virtually wear-free. Wear is the result of the softer of two dissimilar metals being abraded when rubbed together.  In using compatible metal for the rotor, stator and blades, wear is eliminated. Instead, there is a microscopic transfer of material that mates the adjacent surfaces in creating a better seal that reduces friction and improves overall system efficiency over time. We call this process “Vane Gain.”  And while inherently efficient at startup or “zero hours”, the energy efficiency rating of the vane compressor uniquely continues to get even better over time through normal operation.

A 100 horsepower Mattei ultra-performance fixed speed rotary vane air compressor.


Can you describe the positive displacement air compression process in a rotary vane?

The architecture of vane technology makes the air compression process quite unique. Atmospheric air is drawn into the machine through an oversized air filter and inlet valve that minimizes pressure drop. It enters into a compression cell created between each pair of blades and the end covers. As such, the pressure within each compression cell is equal from one end of the pump to the other end. As the pump rotates, the volume within each compression cell decreases and the pressure rises. One-half a rotation takes each cell pressure from atmosphere to the final discharge pressure.

Most positive displacement air compressors use a combination of roller bearings throughout the compression process to offset the radial and axial forces in maintaining the tolerances engineered into the design. Axial forces result in bearing wear due to the presence and absence of axial forces during the load (compression) phase and unload (not compressing) phase as directed by the upper and lower set points of a pressure switch.

What is the importance of what you call the “bearing-less” vane design?

By design, a vane air compressor is perfectly balanced. This is a significant advantage for the end user as it is the key to getting the lowest lifecycle costs in the industry. As with the other positive displacement air compressors, the vane compressor must contend with radial forces. Unlike the others, vane technology is 100% devoid of axial thrust forces. From suction to discharge, the pressure is always perfectly balanced as it is equal across the length of the pump. Thus, a Mattei vane air compressor rotor doesn’t have to contend with thrust forces, so the compressor shaft simply rotates upon a microns thick oil film within a pair of bushes crafted from a proprietary metallic blend that never need maintenance or replacement as there is no wear. In fact, because the compressor shaft rides on an oil film, the original tolerances are a constant that is restored simply and automatically with each oil change. Presently, we are testing PTFE blended bushes that show great promise in further advancing the energy efficiency level of our air and gas compressors.

A 125 horsepower Mattei variable speed rotary vane air compressor.


Is there a recent technological advancement with Mattei rotary vanes you’d like to review?

Absolutely. Today’s Mattei remains clearly focused on continuously improving the energy efficiency and durability of our proprietary vane technology with the goal of building the most energy efficient air compressors money can buy. In 2021, Mattei patented XTREME Injection Technology® which significantly raised the energy efficiency bar where deployed.

XTREME Injection Technology® begins with the use of fluid atomization nozzles that create cone shaped clouds of super fine lubricant fog able to develop thanks to the open compression cells extending throughout the pump and across its axis. These aerosolized droplets provide significantly more surface area than traditional oil injection systems to allow for a much more efficient method of heat transfer to quickly capture the heat from the compression process and stabilize the compressed air at an ideal temperature in real time. This results in high Isentropic Efficiency ratings and a significant reduction in input energy requirements to arrive at some of the best specific power rankings in the industry.

For the initial launch phase, we have deployed this technology on 75-125 horsepower, fixed and variable speed, rotary vane air compressors. Results have been excellent with regard to reliability and efficiency. We are very excited that our 6-pole motor driven RVX UP Series can achieve 2-stage efficiency levels with our proprietary single stage design.

Image of an atomized lubricant cone used in the patented XTREME Injection Technology®. 

I’ve noticed you have a unique approach to the conversation about air compressor lifecycle costs.

Yes, we emphasize the low lifecycle costs of our durable rotary vane technology – and attempt to increase the awareness of the costs of airend overhauls common with other positive displacement air compressor technologies. Nobody wants to pay more for a product than they must. The value of many items is determined by the purchase price. Not so with air compressors. Yes, the purchase price is important but that only represents the “entry fee” to having a compressor. A good rule-of-thumb states that over the life of an air compressor, your lifecycle costs totaling 100% with normal maintenance, are divided into three (3) categories.  

  1. the purchase price (10%)
  2. the cost of electricity to power and run the compressor (80%)
  3. the cost for basic maintenance for the air compressor (10%)

Where vane technology differs in Lifecycle cost conversations is reflected in the elimination of  airend overhauls which can easily exceed 50% of the initial purchase price of competing compression technologies. 

So, while the purchase price is important, the big money is deferred through the high cost of electricity and the specter of needing to overhaul the airend as a result of axial bearing wear. What you can control is defining the electric cost of running the air compressors being offered by performing your due diligence during the purchasing phase. Consider this: if the electricity costs 8x what you paid to purchase the compressor, and you can reduce that value by 20% or more, the compressor is virtually free as the energy savings provide a return-on-investment that exceeds the purchase price. Now, if you eliminate the need to ever have to overhaul the airend you gain a massive financial and long-term reliability advantage.

Thank you for your time.

For more information about the Mattei Group visit or contact Bill Kennedy at

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