The oil in the compressor performs several important functions for the proper operation of the device. What tasks does it perform and which compressor oil should I choose to ensure long-term operation of the machine?
Compressor oil – why is it so important?
The basic task of compressor oil is to reduce friction between the compressing elements of the device. Its use is equally important for both screw and piston compressors. Appropriate lubrication ensures smooth operation of the compression element and at the same time protects it against excessive use. It reduces friction and lowers the temperature of the compression elements that arise during the gas compression process. The grease also seals the compression elements, increasing the efficiency of the process. In a word - properly selected compressor oil guarantees the compressor a longer service life, lower wear of individual elements and, at the same time, higher efficiency.
You will find two types of compressor oils on the market - mineral and synthetic oils. Which compressor oil should I choose? Mineral oil works well in moderate operating conditions without high temperatures and humidity. Its undoubted advantage is its low price. Mineral oil for compressors also undergoes a faster chemical reaction with the water contained in the compressed air, which causes it to degrade relatively quickly. It is worth emphasizing that the product of this reaction is acid, which accelerates the corrosion of the compression elements. That is why it is so important to replace the lubricant relatively often - statistically every 2-2000 operating hours.
Synthetic oil, on the other hand, has much better parameters. It can be used in devices that generate higher temperature and pressure because it does not change its properties under their influence. Synthetic compressor oil ages slower, so it can be replaced every 9000 operating hours or every 2 years. This type of grease has much greater stability, which increases the efficiency of the entire compression system.
How to choose oil for a piston compressor
When selecting oil for the compressor, you must ensure that it is adapted to the parameters of the device. Among them it is worth highlighting:
- auto-ignition temperature - it should not exceed 350 degrees C,
- ignition temperature, which should be approximately 200 degrees C,
- ash content,
- sulfur content,
- humidity.
For the best protection of the compressor, the oil should not contain more than 15% ash, 3% sulfur and its humidity should not exceed 1,5%. Based on this, you will be able to select the type of oil for your device - i.e. mineral or synthetic.
When choosing oil for a piston compressor, it is also worth paying attention to the miscibility curve of the oil with the refrigerant liquid. It is also a good practice to check the condition of the lubricant during operation - the oil should not change its physical and chemical properties during the entire period of operation. This way it will not cause the compressor to fail.
Which oil should you choose for a piston compressor? Oil for a piston compressor should have a low tendency to foam and be resistant to oxidation. At the same time, it should have high anti-corrosion properties and be wear-resistant.
Compressor oil – what do you need to remember?
The oil for the piston compressor should be changed regularly. Generally, it is recommended to replace the lubricant in accordance with the recommendations of the piston compressor manufacturer - this information can be found in the user manual or warranty card. Generally, it is recommended to replace the lubricant at least once a year or after a specified number of hours.
If you plan to change the lubricant yourself, you need to know how much oil to pour into the compressor. Each device has an oil tank in which the lubricant is stored. When topping up or pouring new oil into the compressor, make sure to pour it in an amount slightly larger than the measuring cup marked on the wall. Then you will be sure that the lubricant level in the machine is sufficient.
Replacing the compressor oil on your own for the first time should be supported by a person experienced in the subject - preferably from a proven compressor service. This way you will avoid errors and, consequently, compressor failure. It is also worth reading the manufacturer's recommendations, which describe the oil replacement process in the owner's manual.
