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Air Oil Separator
K Filter High-Performance Compressor Air Oil Separators
At K Filter, we manufacture world-class Air Oil Separator (AOS) filters specifically designed for rotary screw and vane compressors. Our separators are engineered to act as the final defense line, ensuring that your compressed air is 99.9% oil-free while protecting downstream equipment from contamination
Oil from the crankcase can get into the blow-by gases escaping from the engine cylinders. These blow-by gases need to be recirculated back into the cylinders to reduce pressure. The oil content is <1 ppm.
Take advantage of our diverse array of options to find the ideal product for your application.
K Filters are guaranteed to fit, to perform, and to sell equal to or better than the original equipment of other manufacturers and brands.
Oil from the crankcase can get into the blow-by gases escaping from the engine cylinders. These blow-by gases need to be recirculated back into the cylinders to reduce pressure. The oil content is <1 ppm. Take advantage of our diverse array of options to find the ideal product for your application. K Filters are guaranteed to fit, to perform, and to sell equal to or better than the original equipment of other manufacturers and brands.
Separation of oil drops
As per the size of the drops, various effects in physical separation can make the fine drops adsorbed by the micro-glass fibers. The separation efficiency can be affected by the diameter and the number of fibers and also the flow velocity. The reaction between inertia, capillaries, and diffusion effects can be optimized if there is any design modification. The fine oil droplets that are pressed through the separation medium will come together to form larger drops. With the effect of gravity, the fine droplets sink down through the secondary separation medium on the clean side. Complete separation and redirection of the oil droplets in the airflow can be enabled by the correct choice of material together with low flow resistance. This also applies to load fluctuations around the nominal working point.
Wrap type Air Oil separators
The Wrap-type air oil separator is suitable for flow from the outside to the inside. It can be used for the entire range of current versions of screw-type and sliding vane compressors. Our standard wrap elements are particularly insensitive to design variations and achieve optimal results with regard to separation efficiency and service life.
Pressure resistance
Our standard wrap elements designed for pressure differences of at least 5 bar (0.5 MPa).
Separation efficiency
The residual oil content at nominal flow rate and at 7 bar (0.7 MPa) operating pressure is approxi-mately 1 to 3 mg/m3.
Service life
The rise in flow resistance and thus service life primarily depends on the cleanness of the oil and the quality of the air filter. A service life of several thousand hours can be achieved with a well-functioning system.
Pleated Depth Type Air Oil Separators Elements
Pleated depth air oil separators elements product takes up very little space and is suitable for the entire range of current versions of screw-type and sliding vane compressors. In the pleated depth separator element, oil flows from the outside to the inside.
Pressure Drop
The pressure drop at nominal flow rate and at 7 bar (0.7 MPa) operating pressure with a
new element is approx. 0.2 bar (20 KPa). If a higher resistance is permitted, the volumetric
flow rate can be increased to 1.5 times the nominal flow rate without downgrading
performance.
Pressure Resistance (DP)
Depth separator elements are designed for pressure differences of at least 5 bar (0.5 MPa).
Separation Efficiency filter elements
The residual oil content at nominal flow rate and at 7 bar (0.7 MPa) operating pressure is
approx. 1 to 3 mg/m3.
Service life
The rise in flow resistance and thus service life primarily depend on the cleanness of the oil
and the quality of the air filter. A service life of several thousand hours can be achieved with
a well-functioning system.
Spin On Type Air Oil Separator
Spin On type air oil separators using the same concept of the depth separator element take very little space with an additional advantage of as easy change. It’s become very common in compressors up to 5.5 m3/min however there are several applications where this Separators combined in double or triple are used in bigger compressors. The pressure drop at a nominal flow rate and at 7 bar (0.7 MPa) operating pressure with a new element is approx. 0.2 bar (20 KPa).
Pressure resistance
Depth separator elements are designed for pressure differences of at least 5 bar (0.5 MPa).
Oil Separation Efficiency
The residual oil content at a nominal flow rate and at 7 bar (0.7 MPa) operating pressure is
approx. 1 to 3 mg/m3.
Service life
The rise in flow resistance and thus service life primarily depend on the cleanness of the oil
and the quality of the air filter. The service life of usually up to 4000 hours can be achieved
with a well-functioning system.
1. What is the role of an Air Oil Separator in a compressor?
The Air Oil Separator is critical for separating oil, vapors, and solids from the compressed air intake. It uses the coalescence effect, where micro-glass fibers trap fine oil droplets and merge them into larger drops that sink due to gravity. This process ensures an oil carryover of less than 1–3 mg/m³ (1–3 ppm), returning clean oil to the lubrication circuit and delivering pure air to your system
2. Is the K-Filter Air Oil Separator a direct substitute for OE brands?
Yes. K Filter designs are guaranteed to fit and perform equal to or better than original equipment manufacturers (OEMs). Whether you are replacing filters for Atlas Copco, Ingersoll Rand, or Kaeser, our separators—including Wrap-type, Pleated-depth, and Spin-on models—provide a 100% compatible, high-performance alternative.
3. How often should I replace my Compressor Air Oil Separator?
For standard industrial operations in Europe and the Middle East, we recommend:
- Standard Replacement: Every 4,000 run hours or annually.
- Middle East Considerations: In high-dust environments (UAE, KSA, Qatar, Kuwaiti), the separator may clog faster due to fine particles bypassing the air filter. We recommend monitoring the Differential Pressure (DP).
- Mandatory Change: If the pressure drop exceeds 0.8 to 1.0 bar (12–15 PSI), immediate replacement is required to avoid energy loss or separator implosion.
4. How does a K Filter AOS improve energy efficiency?
Energy consumption is directly linked to pressure resistance. Our separators feature a low initial pressure drop—approximately 0.2 bar (20 KPa) when new.
Every 2 PSIG increase in pressure drop across a clogged separator increases your compressor’s brake horsepower (BHP) consumption by 1%. Using a high-quality K-Filter AOS can save up to 15% on annual energy bills.
5. What makes K-Filter’s technology “Ultra-Modern”?
Unlike standard filters, our Air Oil Separators utilize:
- Glue-Free Mechanical Assembly: Eliminates secondary pollution and ensures structural integrity at high temperatures.
- Conductive Grounding: Our seals and media are designed with improved conductive properties to prevent electrostatic discharge (sparks), vital for safety in explosive gas environments (ATEX compliance).
- Advanced Micro-Glass Media: Targeted filtration down to 0.003 microns to handle the smallest aerosols.
6. What are the signs of a failing Air Oil Separator?
- High Oil Carryover: If you notice oil in your downstream air lines or a frequent “low oil level” alert on your compressor.
- Excessive Temperature: A clogged separator forces the compressor to work harder, leading to overheating.
- Pressure Fluctuations: Inconsistent air delivery usually indicates the media is saturated or compromised.
7. Which type of separator do I need: Wrap-type or Spin-on?
- Wrap-Type/Depth Elements: Best for large industrial screw compressors where high flow rates and long service life (several thousand hours) are required.
Spin-On Type: Ideal for smaller compressors (up to 5.5 m³/min) due to their compact design and easy “twist-off” maintenance
Technical Specifications Benefit
| Feature | K Filter Specification | Client Benefit |
| Residual Oil Content | < 1 – 3 ppm | Protects sensitive downstream tools. |
| Initial Pressure Drop | 0.2 bar (20 KPa) | Reduced energy costs. |
| Max Differential Pressure | 5 bar (0.5 MPa) | High burst resistance & safety. |
| Micron Rating | 0.003 – 3 Microns | Optimal particle/vapor separation. |
| Service Life | Up to 4,000 Hours | Reduced maintenance frequency. |
