Why use oil free compressed air ?
The use of compressed air is very common in many companies and industries. Compressed is a utility
like electricity and natural gas. Compressed air is a safe form of energy. It runs processes and tools in small garages , in medium size factories and in large industrial companies. Generating compressed air is an expensive activity. So far all very understandable.
But what about oil free compressed air?
First be need to understand that air generated by a standard piston or screw compressor always contains a residual amount of oil (0.01 – 0.1 mg/m³). This oil contamination can ruin a production process. Industries like food and beverage, pharmaceutical, chemical and petrochemical, semiconductor and electronics, automotive, textile yarns and fibers, specialty gases, paper, glass manufacturing , they absolutely do not want any amount of improper oil contaminant in their production process. That is why these industries use oil free air even though it is very costly to generate.
What is oil free air exactly?
Oil free compressed air is generated differently than regular compressed air. The process of compressing air is done without the injection of oil or without lubrication with oil. In fact the oil does not mix or touch the air while being compressed.
The standard in compressed air oil residue is described in the ISO standards. The particular standard is ISO 8573-1 (year 2010). It describes 5 classes (0-4), where class 4 is the lowest standard (<5mg/m³) and class “0” (zero) is the highest and the purest. Class “0” is in fact specified by the user or supplier but it is for sure more stringent than class “1” (<0.01 mg/m³).
Technical oil free compressed air ?
This is air where oil is filtered out from a regular oil injected compressor. It is different than 100% oil free air from an oil free screw or centrifugal air compressor. Normally this technical oil free air is not used in applications where there are critical standards.