Rotary Screw vs. Reciprocating Air Compressors

rotary screw compressor or reciprocating air compressor

When deciding on the right air compressor for your business, it’s important to distinguish between the two main types available: the rotary screw compressor and the reciprocating/piston compressor. The first notable difference is in their operation. Rotary compressors have two screws that turn in opposite directions, trapping the air between them causing compression. Reciprocating compressors use pistons that move up and down to compress the air inside the cylinder. Although most companies have relied on the uses of reciprocating air compressors and the traditional piston model, comparing the maintenance costs, required application and individual features of both types can help you determine what’s best to help your productivity and bottom line.

Compressor Maintenance

One of the advantages of the rotary screw compressor over the reciprocating compressor is the reduced maintenance requirements and costs. Rotary compressors generally require simple filter and lubricant upkeep. Reciprocating air compressors have multiple parts that require frequent checks such as valves and piston rings. As these parts wear over time, the compressors generate more heat and without a consistently high level of maintenance, can gradually lose performance value.

Compressed Air Applications

When comparing compressor types, it’s important to consider what you will be using it for. A clear advantage of reciprocating air compressors over rotary screw compressors is their ability to work at higher levels. They perform better for jobs requiring pressures above 150 psi. Because of this flexibility of use in demanding applications, they are used in a variety of industries. Additionally, they can be base mounted or mounted directly onto tanks.

Rotary Screw Air Compressors are best suited to run at pressures under 150 psi. This makes them ideal for standard plant industry applications. They are dependable and have long lifecycles, making them a more cost effective option for many medical and industrial facilities. And like reciprocating compressors, they can run on either gas or electricity.


In addition to the varying maintenance costs and distinctive differences of functional application, there are additional features of each compressor type to consider.

Rotary screw compressor features:

 Optional designs and enclosures to reduce noise levels
 More energy efficient
 Generates less heat
 Functional in extreme temperatures
 Safe and relatively small in size
 Continuous operation with no pistons to rest for cooling

Reciprocating compressor features:

 Produces both high power and high pressure
 No oil carryover
 Greater compression range
 Better for intermittent operation
 Most commonly used compressor
 Lower initial set-up cost

There are a lot of complex factors that go into choosing the right compressor for your application. To learn more about which type of air compressor is best for your business, contact a specialist at Lewis Systems. We stay aware of the latest technological advancements and seek out the most energy efficient and economically viable solutions for our customers. We also service a wide variety of compressed air systems and equipment from reliable companies such as Gardner Denver, Kobelco and Becker. Contact us today for more information.

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A Preventive Guide to Keeping Your Air Compressor Contaminant-Free

Compressed air purification equipment is essential to modern production facilities. When selecting the right purification equipment, it’s crucial to consider the required air quality levels, overall cost and how to establish a comprehensive plan to keep your air compressor clean and well-maintained.

Although the quality of air required for your compressed air system will vary depending on what you’re using it for, there are a few main contaminants that need to be considered no matter what its function. Taking preventive action will help your air compressor run more efficiently, promote long-term dependability and reduce the need for costly repairs.

What Contaminants Are Most Concerning?

  • Water. Of all the contaminates that can create issues with an air compressor system, moisture is the number one problem. Condensed water and water aerosols cause corrosion to the storage and distribution systems, reducing performance efficiency and increasing your maintenance costs.
  • Particulates. This is a combination of rust, pipe scale, atmospheric dust and microorganisms. Despite filtration, many of these tiny particles get through, damaging equipment and diminishing the life of the air compressor system and its components.
  • Oil. Many air compressor systems use oil for lubrication, sealing or cooling. Contamination occurs when the oil is drawn into the system as vapor, aerosol or liquid. Once inside, the oil mixes with the water and becomes acidic. This can lead to rust, which damages both the air compressor system and the product itself.

How Can I Limit the Effects of Contamination?

Once you’re aware of the main factors of contamination, air compressor preventive maintenance and cleaning is your best defense for consistent and cost-effective productivity.

  • Location. Installing your compressor in the right location makes everything else easier. Your system should be installed in a clean, well-lit and ventilated area with ample space all around for ease of maintenance. Select a location that provides a cool, clean, dry source of air. In some cases, it may be necessary to install the air filter at some distance from the compressor to obtain proper air supply.
  • Temperature. Overheating will shorten the life of compressor lubricant and cause premature wear and tear. Weekly checks of the coolers are important to prevent future issues. Check for dirt accumulation on the oil or aftercooler core faces and cooling fans. If cleaning is required, clean the exterior fin surfaces of the cores by blowing compressed air carrying a nonflammable safety solvent in the direction opposite to the cooling fan air flow. This will keep the exterior cooling surfaces clean and ensure effective heat dissipation to help avoid the warm conditions that allow microorganisms to thrive.
  • Filter. Spending extra time and money on an advanced filtration system will likely result in financial savings in the long run. The inlet air filter element is your first line of defense in keeping your oil, oil filter and air/oil separator clean and performing properly. Maintain a regular schedule of checking and replacing your inlet air filters. Dirty or clogged air filters reduce your compressor’s efficiency and over time, they can tear, letting contaminates such as larger particulates into your compressor. Newer compressors can help you with preventive maintenance by monitoring inlet air filters and will advise you when a filter requires servicing. Another helpful option is to choose an oil-free air compressor, which not only eliminates the possibility of oil contaminates altogether, but is also better for the environment and helps reduce energy costs.
  • Oil. If your compressor is oil lubricated, nothing will shut your system down faster than running low on oil or exceeding your lubricant’s life. Having a regular oil analysis program in place and checking oil levels daily ensures that your compressor is maximizing its efficiency. And always remember to never mix lubricants in your system.

Lewis Systems would be happy to review your compressed air needs. Whether you have an oil-free, rotary screw or reciprocating air compressor that needs cleaning, regular maintenance or repair, contact us today for the finest factory trained and certified technicians and 24/7 service. Our four convenient locations are ready to serve you. For more updates on the latest air compressor tips and trends, follow us on LinkedIn.

Proper Maintenance of Gas Detection Equipment

No matter the size of your gas system, failsafe operations are always a top priority. Checking and maintaining your hazardous gas monitoring equipment on a regular basis is essential for the safety of employees and for optimum equipment performance. A sensor that has not been properly maintained could lead to false atmospheric readings, which can jeopardize your staff and your investment. With new regulatory standards evolving all the time, how do you know you’re getting the most accurate readings? The answer isn’t just performing periodic bump tests. Only through routine calibrations and careful record keeping can you be sure to maintain the highest standards of safety for your business.

Bump Tests vs Calibration

A simple bump test, or function check, can be performed frequently to verify that the gas detector sensor and alarms are working. A bump test involves briefly exposing the sensors to a higher concentration of gas than normal in order to set off the alarms. This is quick and easy, but bump tests alone aren’t enough to ensure the safety of your facility and staff, as they only check for functionality. Although they can detect the presence of gas in the air, it’s important to remember that they don’t check for instrumentation accuracy or make adjustments to the sensor itself. That’s where the importance of consistent calibration maintenance comes into play.

Regular calibration is crucial to maintaining the overall working condition of the gas monitor. How often you need to calibrate depends on many factors, including the type of equipment, operating conditions, environmental factors, instrument use patterns, sensor replacements and many other variables. Over time, the sensors become less accurate at reading the level of gas. This is known as calibration drift, and occurs with all gas detection systems, no matter how new or well-maintained they are. The best way to guarantee consistent safety is to have a bump check and calibration routine in place in your company’s policy standards. This will ensure you can rely on your detector to alert you in the event of toxic leaks or exposure.

Know Your Records

Keeping accurate and updated records of sensor replacements, equipment updates, bump test results and calibration dates is the best way to predict costs and maintain safety standards. Know the typical lifespan of the sensors in your monitor and note these dates so you can plan ahead. This record will also help your bottom line by allowing you to identify any parts of your equipment that have a history of excessive maintenance costs or often make inaccurate readings. Included with these documents should be the user manuals for all parts and equipment. This will help support a regular maintenance schedule, since equipment manufacturers often include information about the recommended calibration frequency, the parts needed for calibrating your equipment and the calibration procedures. To complete your records, online resources are often available, such as ENMET’s Equipment Video Page or the ENMET YouTube channel, which provides the specific calibration instructions for their gas detection equipment.

Lewis Systems is an authorized distributor for ENMET and can help your company with the right combination of new or replacement gas detection parts and calibration services to ensure your company stays protected. To find out more about the importance of gas detection equipment maintenance, or to get a recommendation for how often to calibrate and check your equipment, contact us online or call 888.382.8077.

Could Leak Detection Help You Cut Costs?

leak detection for air compressors

Compressed air leaks can be a huge energy drain on your business. They can sometimes be the difference between running your normal compressor system and being forced to turn on your backup. To really put this in perspective, consider that a ¼” air leak at 100 psig can waste as much as 104 CFM of compressed air. This is equivalent to a 25 HP compressor, and in energy dollars, can mean losing as much as $8,000 a year in power cost.

Benefits of Detecting and Repairing Compressed Air Leaks:

  • Reduce energy consumption and operating expenses
  • Identify equipment that is failing or not operating properly
  • Reduce the load on your compressed air equipment
  • Improve plant safety

Identifying Leaks Efficiently

There are two major ways to find leaks. The first is to turn off all production equipment, then walk the facility to mark and fix leaks. The second, more efficient option, is to use an ultrasonic leak detector to find the leaks while the facility is in production. Ultrasonic leak detection offers a simple, non-invasive way to quickly identify leaks that can be tagged and later repaired. This technology could help your operation identify costly issues and minimize waste. Think you might have a leak? Contact your local Lewis Systems for more details and pricing.

Gardner Denver RBS Blowers: Top 3 Design Advantages

Gardner Denver RBS positive displacement blowers and vacuum pumps bring incredible value to the industrial PD market. These robust tri-lobe pumps have a multitude of design advantages. Here are your top three:

  1. Durability
    • Piston Ring Air Seals – ensure oil-free air and last longer
    • Dual Splash Lube – dissipates heat and reduces maintenance intervals
    • Reinforced Bearings – 100,000-hour lifespan
    • High Strength Shafts – allow for higher overhung loads and eliminate the need for jack shafts or pillow blocks
  2. Efficiency
    • Tri-Lobe Rotors – greater performance and efficiencies than bi-lobe blowers reducing operating costs
    • Cylinder and Support Ribs – cast directly into the cylinder reducing deflections under heavy loads
  3. Sound Levels
    • Tri-Lobe Rotors – solid rotor design offers quieter operation reducing enclosure requirements
    • Helical Gears – provide smooth and quiet operation at all speedsadvantages of blowers and vacuum pumps

For more updates on the latest air compressor trends, follow us on LinkedIn. Or, if you need additional information or assistance with your air compressor system, contact us today.