Sandin compressor locking up?

Some Sandens have a small pressure-relief valve on the rear head. I put a PRV on one I installed on my 1964 Valiant. I recall ~220 psig (~$8 ebay). If the belt is tight enough, the clutch will usually slip first. When that happens, it quickly gets really hot and slings molten plastic out. That happened in our 2002 T&C on an afternoon when it was 108 F. I didn't help it by adding a can of refrigerant after it wasn't cooling well enough that morning and measured the low-side slightly low.

But, the pistons can also seize in the bores. That happened in our 1996 Voyager w/ Denso compressor (similar to Sanden). I tore it apart and found the black anodizing had worn off one piston, causing it to jam in the aluminum bore. I had to really beat it out. That was at ~200k miles, so might be about their life in challenging GA and CA where it lived. My guess is that is a sudden event since bare Al likes to stick to bare Al.