Companies in the automotive, food and beverage, chemical, electronics, pharmaceuticals and health care industries use oil-free air compressors to produce quality air for their operations. While there are several misconceptions about oil-free air compressors, thorough research can help your organization better understand these machines.
8 Oil-Free Air Compressor Myths
Many people have certain presumptions about the features and functionality of oil-free air compressors. Understanding how these air compressor models perform and their various components can help your company determine if they are right for your operations.
Discover the facts with this list of oil-free air compressor myths.
1. Oil-Free Air Compressors Don’t Use Oil
Oil-free machines do not use oil within the compression chamber. However, oil-free air compressor lubrication still relies partially on oil. Oil can help lubricate moving parts within the gearbox and cool the compressor. These compressors use a complex sealing process to ensure the oil remains separate from the compressed air chamber.
2. The Air Compressor Is the Main Cause of Contamination in the System
While air compressors can contribute to contamination as the air moves through various components, they are not the primary source. Atmospheric air pulled in by air compressors can already contain several contaminants, including oil vapor, water vapor, dirt and microorganisms.
Oil-free compressed air can also encounter contamination once it leaves the compressor. The compressed air storage and piping systems produce more condensation as they receive, hold and transport compressed air. The increased moisture causes a higher risk of scale accumulation, microbial growth and rust formation.
3. Oil-Free Air Compressors Provide Contamination-Free Air
Because oil-free air compressors separate oil lubrication systems from the compression chamber, many companies believe these models will produce higher-quality air with less contamination. However, you can expect some particles to pass through. On their own, these compressors provide oil-free compressed air, but the following contaminants can still enter the compressed air stream:
- Water vapor
- Dirt
- Microorganisms
- Water aerosols
- Condensed liquid water
- Rust
- Scale
Pairing your oil-free air compressors with filtration and purification systems can reduce the impact of contamination.
4. Oil-Free Air Compressors Guarantee Oil-Free Air
While oil-free systems efficiently separate oil from the air by sealing, lubricating and cooling elements away from the compression chamber, oil can enter the chamber through atmospheric air. For example, vehicle exhausts can release oil vapor, which can enter the system.
5. Oil-Free Air Compressors Do Not Need Purification Equipment
Purification processes and systems are essential aspects of oil-injected air compressors, and the same is true for oil-free models. When contaminants enter systems, purification processes aim to remove particles for more comprehensive treatment. Oil-free air compressors typically use two purification and filtration strategies — coalescing filters and compressed air dryers.
Coalescing filters consist of two filtration levels. The first is a general-purpose filter that removes the bulk of contaminants from the air. It is a support system for the remaining high-efficiency filter. The high-efficiency filter can then remove the remaining contaminants for excellent results.
The compressed air dryers work with coalescing filters for improved performance to remove water vapor from the air. Together, these systems provide better quality air that you can use in various applications.
6. Oil-Free Air Compressors Always Produce Class 0 Oil-Free Air
Organizations use air quality classifications to indicate how many contaminants remain in compressed air. The International Organization for Standardization (ISO) categorizes air quality by number. Class 0 air is the most rigorous classification, ensuring higher quality air.
While oil-free processes can effectively eliminate oil contamination risk by sealing oil from the compression chamber, this option is not free of contamination and does not automatically meet Class 0 standards. ISO 8573-1:2010 outlines the requirements and procedures organizations must meet to qualify as Class 0 air producers.
When exploring oil-free air compressor models, it’s important to remember that many manufacturers wrongly claim their equipment is Class 0-compliant. Testing situations can also cause discrepancies between manufacturer and user results. Manufacturers often test their air compressors in clean, controlled environments where there are minimal risks of them interacting with many common contaminants.
Companies use air compressors in environments exposed to different air qualities and contaminants. Changing conditions will result in different contamination levels after testing, possibly disqualifying air from being classified as ISO Class 0.
7. ‘Technically Oil-Free’ Alternatives Are as Effective as Oil-Free Air Compressors
“Technically oil-free” air compressors are oil-injected air compressors with filters to remove oil. These alternatives are less effective than oil-free air compressors and are ranked as ISO Class 1. Class 0-certified compressors ensure the cleanest air.
8. Oil-Free Air Compressors Do Not Require Any Maintenance
While oil-free systems require less maintenance than oil-injected options, they do require some upkeep. The following are key tasks to prioritize:
- Changing filters
- Inspecting belts
- Removing dirt or debris
- Draining the air tank
- Checking for leaks
Types of Oil-Free Air Compressors
Despite their various misconceptions, oil-free air compressors benefit companies across industries. When considering an oil-free air compressor, learning the types can ensure you choose the model that best suits your applications and processes. Some types of oil-free air compressors include:
- Reciprocating compressors: This air compressor uses positive displacement to create higher air pressures. It is excellent at dissipating heat produced during compression, reducing the strain in cooling systems. Oil-free versions use a Teflon piston ring in place of oil.
- Scroll compressors: Scroll compressors have two spirals that draw air into the compression chamber. One is stationary, while the other turns. The movement allows the air to cool in the tank’s center. Many models are oil-free.
- Rotary screw compressors: Like reciprocating compressors, rotary screw compressors use displacement to complete the compression process. Interlocking screws draw air into the tank and reduce the available space to compress it. Oil-free models use non-contacting carbon ring seals to aid cooling.
Oil-Free Air Compressor Pros and Cons
The most significant advantage of oil-free air compressors is they produce cleaner air. Class 0-certified models, in particular, can produce 100% oil-free air. Potential downsides of oil-free models include the higher initial cost and potential for contamination if not using a Class 0-certified machine. However, when air quality is a priority, oil-free air compressors can meet your needs.
Learn More About Quincy Oil-Free Compressors
Oil-free air compressors are complicated pieces of equipment. If you have questions about this machinery type or specific models, speaking with experts can efficiently provide accurate, reliable information.
Quincy Compressor designs and sells high-performing air compressors, including oil-free models. Our trained professionals are experts in the products and their applications, enabling them to provide the best services to clients.
Contact Quincy Compressor today to connect with an expert and learn more about this type of air compressor.
