What type of hydraulic oil to use in CAF system screw compressors is a common question.
The answer – The Right Oil!!!
Here is a list of some (but make sure you check your systems specs and maintenance documents to be sure):
- Waterous Compressors – AW 68 or ISO 68 – Low Foaming Oil
- Darley – it is based on the system – Check Here!!
- Pierce – it might be ISO 68 or ATF depending on the system
- Rowe – Tamrotor Oil
Here at CompressedAirFoam.com, we do not recommend any specific brand, however, think carefully if you find a brand that is much cheaper than others.
Hydraulic oil can over time absorb moisture (even from the high RH in the air being compressed). This is evidenced and detected in the slow increase in the system oil level and the oil can slowly change to a milky white color. If the oil level is properly set halfway up the site glass, you will notice a slow increase in the oil level and color change as moisture is absorbed. The oil color desired in the site glass will be the color of the oil when purchased.
Low quality oils, or non-low foaming oils will bubble up during operation. These bubbles can pop and atomize the oil particulates which can then push through the air/oil separator filter, sending the oil along with the air out the hose stream. This will result in a drop in the oil within the CAF system. Again, this can be detected by observation of the oil level on the site glass.
Follow the system manufacturer’s recommendations for how often oil needs to be changed. Some recommend annually, however, if there is a rapid moisture build up, or a drop in the oil level, more frequent service might be warranted.
The cheapest oil will probably cost you more in the long run. Always look for a good quality oil.
