[woody]

Originally Posted by cummings66

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Here's the question I've been pondering.


I've been told by almost every dive shop I've been to that you never want a first stage to lose pressure under water by shutting off the valve because it will flood and need to be serviced. Not to mention the SPG may be damaged.

It is possible that you will get some water past the second stage and into the hose leading to thefirst stage. You should not get any water in to the first stage at all under the condition that you are doing a valve drill.

What's the truth of the matter? Are there some first stages that won't flood, brands? I am of course assuming that all the first stages we're using are sealed environmental types because in the <?:namespace prefix = st1 ns = "urn:schemas-microsoft-comffice:smarttags" /><st1lace w:st="on">Midwest</st1lace> the water is usually cold.

All environmental sealed first stages do not allowwater to enter the regulator at all. That is what gives them the environmental seal. Most non-environmental sealed regulators allow water to enter the regulator to increase the pressure that is delivered to the second stage. This keeps the regulator system performing the same at 10' as at 80'.
Thanks,
Woody