Hey all, apparently I can’t leave well-enough alone with new things…

I’ve pulled the copper tube off of my compressor that runs from the pump to the check-valve on the tank. On the check valve side it’s a fairly straightforward 1/2″ compression fitting with captive sleeve. On the pump side, however, it’s not something that I can identify.

It is some kind of compression fitting, but not one that I’m used to. The outer diameter of the threads themselves on the male end on the pump checked at 0.744″, basically 3/4″. The unthreaded inside part of the fitting on the pump is 0.506″.

The outside of the compression nut itself is 0.898″, which is also 22.82mm, very close to 23mm. The inside of the compression nut is 0.697″ inside of the threads. I couldn’t get a thread density measurement but I’d call them course…

I’ll try to post some pictures when I can.

Any suggestions as to what this fitting is would be much appreciated. I’m planning on running the air from the pump into a condenser coil before it goes back to the tank, and I’d like to sit the original parts aside so that if I have to put it back to original I can, so I need to find the correct fittings to make that happen.

Thanks,