I-R and Gardner Denver piston compressors pre-1980 were almost bullet-proof. Change the oil yearly and valve job at 5,000 hours. Most people didn’t bother - they just ran them. Once CNC lathes were able to machine the helix required to make screws, their price per CFM beat the piston compressors by a lot. Both can be problematic if you try to start them with very cold oil. Screw compressors are oil-flooded and have a micron-level air/oil separator element. If the air filter isn’t maintained, dirt plugs the separator, it collapses and the oil gets pumped out with the air leading to catastrophic failure. Usually somebody notices all the oil where it’s not supposed to be before meltdown.
