[PSUBS-MAILIST] Compressed Air Quality

[Robert Carlson <rob.carlson@gte.net>]

Is air used for scuba diving dry enough for blowing MBTs?  The reason I
ask is that the USS Thresher sank during sea trials due to the fact that

the air when discharged to the MBTs created a tempature that was below
the Dew Point and consequently the orifice quickly froze with ice.
Following this incident the US Navy created rigorous standards for HP
air. Are psubs in jeopardy of a similiar error by using scuba air?

I do recall that scuba tank air is dry (based on the cotton mouth after
the dive) but is it consistantly dry enough for psub purposes?  Or is it

that the possibilities are minimized because of a) the diameter of pipe
is large enough b) the duration of a MBT blow is shorter on a psub and
thus less likely to happen c) combination of a and b and that scuba air
is dry enough.

I'm just curious if anyone has given this much thought.  I do realize
that this probably is not a major issue otherwise there would more
psubbers at the bottom of some dark and cold body of water however my
icuriosity has made me ask why this not an issue.

Regards,
Rob Carlson