Quote: (Originally Posted by
Packhorse)

Oh I see. Thanks for clearing that up for me.
Another solution would be to find a solinoid that can opperate at higher pressure then. I recall someone saying they had a new solinoid developed for Rebreather's. Was is narked@90? This may be worth looking at.
Or instead of a second O2 tank how about a H or Y valve with a fixed IP reg and a compensating one?
yes x-valve would work, however difficult to get two 1stages into the rebreather, particular with optima and inspiration.
Furthermore you might get confused when trying to turn on tank off which valve to turn, or you might not even able to reach one of them.
so second on-board tank seems for me most favourable