One? Perhaps you could count again. For example, in the drawing above...September 21 2008 at 10:51 AM
Steve in NC (Login pneuguy)
Response to Actually it only adds one additional moving part.....
...I see a valve stem, spring, and several seals, at least three of which involve motion. Of all the components in an airgun, it's seals that accommodate motion that are the most likely to be maintenance issues. Also - good regulator designs will usually incorporate some means of adjusting the setpoint pressure without disassembly, which requires more moving parts and seals.
Meanwhile, your example of the USFT is a good one that proves my point that, given a large enough reservoir, self-regulation can deliver exactly as good consistency as can a regulator.