R12 Schrader Valves

In tire parlance, there are a couple of different versions, some are quite long and I don't know why. "I THINK" there are smaller ones for some special application. But so far as I know any AC/ refrigeration ones are the same until the new "quick connectors" for R134 and some other special stuff and I just don't know about them.

Other than that, most all the tire ones I've dealt with and any of the AC/ refrigeration ones were the same. My Cummins even has one for the transfer pump (lift pump) pressure / bleeding.

The port size (flare size) is sometimes different, AKA my old 86 Ranger used some special small size for I think the high side of the AC. "Standard" is 1/4 SAE flare. I'm told that some "mini split" systems use 5/16 flare, at least on one fitting.