Common Types of Air Compressor Repair

Lewis Systems & Service Co., Inc. not only sells new and used air compressors but a good part of our business is based around air compressor repair and servicing. Below is a list of some common air compressor repairs that we address in the field. This is not a troubleshooting guide or instructions on how to do repairs, however if your unit is serviced on a regular basis, a lot of these problems can be prevented.

Reciprocating Compressors:air compressor repair tips

  • Rings – As the piston rings wear out, excessive oil consumption will rise.
  • Valves – Carbon deposits can build up on the valves causing the compressor to take longer to build up pressure. They usually need regular cleaning or replacing if damaged.
  • Controls – Defective pressure switch can cause starting problems as well as a faulty check valve. Problems with the pilot valve can cause the compressor not to unload properly.
  • Belts can be too tight or too loose, also the pulley could be out of alignment causing excessive wear on the belts.
  • Air intake filters should be inspected and changed on a regular basis. Dirty air filters can cause long pump up times and overheating.
  • Routine Maintenance Items: Changing the air filter and oil on a regular basis will prevent many problems. It will also extend the life of valves and rings.

Rotary Screw Compressors:common types of air compressor repair

  • Controls / Check Valves: The majority of problems that arise on rotary screw compressors are related to the controls and sensors. A faulty pressure transducer or a sticky thermal valve element can shut your compressor down very quickly. It’s always good practice to have these items in stock or at least know a reliable service center (we suggest Lewis Systems), that normally has these items in stock.
  • Not Building Pressure: Number one cause: a dirty inlet air filter. Also problems with the inlet valve or minimum pressure valve. Both should be inspected and cleaned on a regular basis. Both normally have packing rings or seals that need to be replaced occasionally.
  • Inlet Valve Maintenance
  • Excessive Oil Carryover: A common cause for oil carryover is a blocked or faulty scavenge line check valve. Oil separators can rupture if they are not changed on a regular basis which will cause oil carryover as well.
  • Routine Maintenance Items: Changing the air filter and oil filter on a regular basis will prevent many problems. It will also extend the life of the compressor lubricant and oil cooler.
  • As you can see, there are lots of maintenance and repair issues that should be addressed on your air compressor. Don’t forget that Lewis Systems & Service Co., Inc. has a fully staffed service department at each of our locations to assist you. From emergency repairs to proactive maintenance agreements we can help keep your plant up and running.

Common Applications for PD Blowers and Vacuum Pumps

TriFlow Rotors Tri Lobe DesignPositive displacement (PD) blowers and vacuum pumps take advantage of positive displacement technology; which causes movement by trapping a fixed amount of air then forcing (displacing) that trapped volume into the discharge pipe. These pumps can be further classified depending on what type of mechanism is used to move the air.

Positive displacement blowers usually come in either bi-lobe or tri-lobe configurations. Bi-lobe blowers and vacuum pumps have been around for a long time and are used in a wide variety of applications because of their durability and flexibility. Tri-lobe blowers usually can operate with higher throughput than the standard bi-lobe units. Tri-lobe blowers often operate with less noise and pulsation levels as well. Another design configuration available to both bi-lobe and tri-lobe blowers is a helical lobe design which can allow for even more noise and pulsation reduction.

HeliFlow RotorsYet another more recent improvement is the helical screw blower which offers reduced energy consumption compared to traditional lobe blowers as well as eliminating the pulsation that standard lobe blowers create. Helical screw blowers can reach higher pressures than lobe blowers, but can’t produce the higher flow rates that lobe blowers are known for.

In general, positive displacement blowers are most effective with high volumes at low vacuums and pressures. Choosing the right blower is critical to maximizing productivity and ROI. There are so many different variables that need to be addressed that it is hard to tag a specific style blower to a specific application. A general overview of applications in which you would find PD blowers being used can be found below:

Aquaculture – Aeration Oil & Gas – Gas Collection & Sparging
Cement – Fluidization & Conveying Fly Ash Conveying
Chemical – Vacuum Processing & Conveying Gas Boosting
Coal /Landfill – Methane Gas Recovery Chip Conveying
Dairy – Automated Milking Processing & Conveying
Dry Bulk Handling – Trailer Unloading Potholing & Slurry Recovery
Vacuum Extraction & Sparging Environmental – Sewer Cleaning
Industrial – Material Vacuuming Aeration & Backwashing

Summer Preventative Maintenance For Your Compressed Air System

Heat Exchanger

Heat Exchanger

During the summer, there are a few extra challenges your compressed air system faces. Heat and humidity can cause all sorts of problems if you don’t prepare your system to adequately address them. Here are a few simple reminders of things to check to prevent downstream problems and equipment failures.

  • Condensate Drains – With the extra humidity there will be extra water. Check all of your drains and drain lines to ensure they are sized correctly and operating properly.
  • Heat Exchangers – Check your after coolers and oil coolers to make sure they are clean and the fans are operating correctly. These coolers are your primary defense for keeping your oil temperatures acceptable and removing the bulk of your liquid water from your compressed air system.
  • Gardner Denver Heated Purge DryerAir Dryers – Both refrigerated and desiccant compressed air dryers need to be checked and prepared for the summer heat and humidity. Condenser coils and condenser fans should be checked on refrigerated dryers. Pre-filters and drains should be checked and serviced on desiccant dryers to protect the desiccant bed from slugs of liquid water and oil.
  • Oil/Water Separators – All the water that your drains and dryers are removing should be routed to an Oil/Water Separator. These separators help you safely and legally dispose of your compressed air condensate. Be sure to replace all carbon bags and filters to ensure proper operation.



Lewis Systems & Service Co., Inc. carries a full line of drains, dryers and filters to help your compressed air systems to deal with the heat and humidity that the summer brings. So give us a call if you find yourself “under water” this summer.


Benefits of Investing in Quality Pre-Owned Compressed Air Equipment

Is your company looking for medical or industrial air solutions in the Carolinas or Virginia but concerned about investing too much up front? For quality units and parts that don’t break the bank, consider purchasing refurbished or pre-owned compressed air equipment from Lewis Systems. Our team of over 20 factory trained and certified technicians have 30+ years in the business, which allows us to not only rebuild old air units, but evaluate the remaining lifetime of compressors still running. Below is a list of the top benefits to keep in mind when making your next purchase.

Rescued unit before rebuild

    1. Lower Upfront Cost: The most obvious reason. Buying a used compressor or dryer requires a significantly lower outlay of capital money than purchasing a new one. If you’re adding equipment just as a temporary system, or maybe just for intermittent use, purchasing used can sometimes make the most sense.
    2. Service and Support: Buying used equipment from an auction or plant closing would seem like a great way to save some money, usually however there is no assurance that it is in good condition or that it even will operate correctly. It may be cheap but could very well end up costing you a lot of time and money in the long run. Purchasing used equipment from a reputable service dealer, carries the assurance that it has been inspected, tested and serviced. Normally a warranty period will be offered as well to give you the confidence that the unit will operate properly.

Rebuilt unit, serviced and ready for a new home.

  1. Better Quality = Less Cost: In some cases you can get a better quality used compressor for close to the same price as a lesser quality / brand of compressor that is new. Instead of just buying something because it’s cheap and new, do some research and look for the more reputable brands that are built to last. Buying a respected well known brand that is used means you’ll still have access to repair parts and service when you do need it.
  2. Eco-Friendly Approach: In the right situation, purchasing used may be the “greenest” way to go. Re-purposing used equipment is an effective way to save natural resources, protect the environment and save money. Making new equipment requires a lot of materials and energy. An energy efficient used compressor can come with a much smaller carbon footprint than a brand new one.

Lewis Systems & Service Co., Inc. has over 40,000 square feet of warehouse space dedicated to used and rebuilt equipment. We take great pride in rebuilding and re-purposing equipment that has a lot of life left in it. Give us a call to discuss your specific requirements and we’ll do our best to find the right equipment for you.

Types Of Air Compressors

There are many types of air compressors that come in different sizes. Each application is unique and there is usually a correct compressor for a specific application or requirement. The right compressor, properly maintained and utilized, saves labor, energy costs, and often generates a boost in productivity. With increasing electrical rates and a trend toward smaller maintenance teams, the best choices in air compressors operate with the efficiency and reliability to work better, longer and with less maintenance. Below are several examples of air compressor technologies that are currently used.

types of air compressorsScroll Air Compressors: Uses two spiral elements, one stationary, one orbiting to produce oil-free, contaminant-free compressed air. Scroll compressors are extremely quiet, compact, require very little maintenance and of course are oil-free. Typical applications are Medical, Laboratory, Dental, Food and Beverage, Pharmaceutical and Electronics.

reciprocating air compressorsReciprocating Air Compressors: This technology employs a piston moving forward in a cylinder via a connecting rod and crankshaft. The reciprocating air compressor is extremely versatile. They can be found in the smallest auto repair shops to the largest manufacturing plants. It compresses both air and gases with very little alterations and is the only design capable of compressing air and gas to high pressures.

rotary vane air compressorsRotary Vane Air Compressors: Rotary vane compressors cover a wide performance range and come in dry running and oil lubricated versions. Oil lubricated rotary vanes are the standard pump in numerous industrial applications.

The single rotor design with sliding vanes allows the use of a direct drive arrangement, without the need for belts or pulleys. Its simplistic design and proven reliability make it a viable alternative to other technologies. Its compact size also makes it an ideal choice for customized compressed air and gas applications especially in the transit industry.

rotary screw air compressorsRotary Screw Air Compressors: Rotary screw technology serves the majority of industrial applications today in the 15-500 HP range. It uses male and female rotors that move towards each other while the volume between them and the housing decreases. The screw element is not equipped with any valves and there are no mechanical forces to create any imbalance. It can therefore work at high shaft speed and combine a large flow rate with small exterior dimensions. Typical applications would be Automotive, Food and Beverage, Petrochemical, Aerospace and Electronics manufacturing.

centrifugal air compressorsCentrifugal Air Compressors: Air is compressed by the mechanical action of high-speed, rotating impellers imparting velocity and pressure to the air. Approximately half of the pressure energy is developed in the impeller, with the other half achieved by converting velocity energy to pressure energy as the air speed is reduced in a diffuser and volute. Centrifugal air compressors are best suited for high flow, oil-free applications. Newer designs that use magnetic bearings and high speed motors can offer outstanding efficiency and reliability. Typical applications would be Textiles, Pharmaceuticals, Natural Gas and Chemical industries.

Cost of Ownership: There are many ways to improve compressor efficiency and reduce compressed air cost of ownership, and this doesn’t always involve investing in new equipment. Lewis Systems & Service Co., Inc. can help improve the efficiency and functionality of the entire compressed air system by performing a compressed air audit. We can help you uncover ways to improve your energy efficiency and make significant reductions in operating costs.

A note about service and maintenance: Industry figures estimate that compressed air systems can waste up to 30% of the compressed air through leaks, poor controls or lack of maintenance. In addition, compressor efficiency may degrade with age. Therefore, no matter what type of air compressor your plant has, implementing a compressed air maintenance program is essential to ensure a high level of performance over the years. Lewis Systems & Service Co., Inc. can help you design a program for your in house personnel or we can take care of all your equipment through a custom designed preventative maintenance agreement.

If you’re in need of air compressor services in Virgina or North Carolina, contact our team today at (800) 222-4553!