Quote Originally Posted by guapo
I have also twin screw compressor but I have to overhaul that every three months bearing always damaged.
This suggest the problem is with the repair work, a serious fault in the compressor installation, or some unknown problem with the system causing these frequent faults.

This should not be taken as a reason as to why mono-screws are better than twin screws. Something is wrong here, and not just with the bearings (unless the replacement bearings are a poor quality substitute).