Do your expanders require lubricant?
Air Squared expanders can be operated either oil-free or with lubricant.
Most expanders are designed to operate oil-free, yet semi-hermetic sealing features common to all expander models make them suitable for lubricated operation as well.
In most cases, if the application allows for lubrication, it should be used. Lubrication offers a ~12% efficiency increase and extends product life.