A very good clean up and putting it back together resulted initially in it working as it should. Connected via the pcl airline fitting it would seal when the correct way up and open if the float was allowed to move by inverting it. All well and good - but further tests showed that if it was left for a little while it would again stick in the open state
OK - pull it apart again, clean it again, test it again and sadly get the same results AGAIN
So, the logical thing to do is replace it, as it needs to be reliable for a long period. However the way it is mounted doesn't leave enough room for industry standard auto drain valves - they are 185 mm tall in this bore size, and I only have 140 mm to play with
Now I was sure that I recognised the layout of the internals of the inner valve, then it came to me last night - yes - VERY similar to the auto drain that is internal to an 'Olympian' regulator / drier set I'd used years ago and now was in the 'air bits bin' - I just wonder
So it was pulled apart and bingo - pretty well identical - thread mounting size the same - sealing arrangement to the enclosure the same.
Looking at the 'bomb' shaped housing, I reckon that Ingersol Rand ran out of space and made up a custom short housing to hold an industry standard auto drain valve module
Anyway, it's in, and on test working as I type
(This beast is a proper refrigerated drier complete with compressor, radiator etc just like your fridge )