Since I am able to regulate the pressure coming out of the O2 tank, this looks like it will work. Since the valves are for water, even with a super tight hose connection over the ribs, there is still a bit of a leak. I'm going to find some super small hose clamps to see if that will solve the leak on the input side when the valve is closed. Output side does not need any clamps since the back pressure is minimal as it's going into my lungs.
Thanks again. I'll post another update.