| Re: Why not redundant one-way valves?
The death you mentioned was on a passive SCR. Since the valve was deformed, there was no dumping thus resulting in no new gas added.
So after a while, the loop became hypoxic and the diver passed out.
As far the mushroom valve on a CCR, it isn't quite the same.
On an eCCR, the electronic will keep the PO2 at set-point. On mCCR, the orifice will continue to add O2. But the critical thing is the diver has 3 O2 sensors to monitor the loop.
The chance of the loop becoming hypoxic is very unlikely.
However, a deformed mushroom valve on the DSV will create a hypercapnic loop condition. And as you have learned in your CCR course, the symptoms are different than hypoxic. And it is more likely that the diver will recognize the problem.
Add 2 more valves to make 4 falls under the same idea of having 6 O2 sensors monitoring the loop. Where is the optimum balance before deminishing return ?
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