David Krall asks [231206 MMD] if Simplex pneumatics could be mounted
vertically. I have worked with Simplex pneumatic blocks only once.
It would seem to me that if they did work vertically, their performance
would be impaired.

Pouches and valves rely heavily on gravity, and if gravity is changed
by 90 degrees it would likely make the valve response much more
sluggish.

I have no experience, but this is my insight.

Ed Chaban