Hi, I'm working on what (I now think) is schematically similar to a scuba diving second stage regulator. Fundamentally, it uses normal lung inspiration to move a diaphragm, or piston, which in turn moves a lever that opens a valve to a tiny tank under high pressure (about 3-4 bar). i.e. the diaphragm and lever are the mechanical advantage for normal lung inspiration (about 1.4 CIW) to open the valve. I have no ambient pressure and temperature issues (not underwater), but size is a concern. Tending to tiny is good. A real scuba regulator size is gargantuan. Would anyone know where I can access a cut section, or reasonably accurate, 3D CAD files of an adjustable or non-adjustable scuba second stage regulator for reference? Or any design-engineering tips is much appreciated.