Many times I have run into a problem when having to change the oil in a semi hermetic compressor because the large drain plug ends up to low for a pan to slide under and has machine threads so I can't just screw in a male by flare hose fitting either. I'm thinking about drilling out an old Copeland drain plug and tapping the hole in the center as pipe thread. I am aware of the aftermarket oil change valve kits out there with the internal dip tube, but that doesn't help when the compressor you approach never seems to have one ! If I had this type of drain plug, I could simply close the service valves, pull a vaccum on the compressor and not spill a drop of oil while removing the existing plug to install the fitting. Any ideas ?