Thermo Pro Valve vs. 300 Bar DIN

[Leadking]

I was under the impression that since an H valve has a single burst disk for both firsts, it isn't considered redundant.

At least with a doubles set up with a manifold, if one disk fails, you can isolate that tank protecting your remaining air supply.

When I was in the OP's stage of diving, I looked at the H valve, because I wanted redundancy. It didn't provide it and I'm currently diving a single configuration with a slung pony.

The safety is there to protect the tank, not a regulator. I am not aware of any system (other than a true isolator/crossover) that if the safety goes, that it will not allow the tank to empty.

 

[WD8CDH]

Would an example be someone diving doubles with Isolation Manifold, failing to open valve, breathing down one tank empty while their SPG shows a full tank?

Yes and another example would be only getting a 1/2 fill with the isolator closed at the fill station. Of course, all of these "operator errors" might be detected before they cause a problem, but they might not(and often haven't).