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Alan, if you could position an altimeter (or some other type
of vacuum gauge) where it's visible through a view port, then run the pump until
you reach 100,000 feet of altitude on the altimeter, close the valve, and leave
it overnight, seems like that would tell you if you have any [low pressure]
leaks when you check the altimeter in the morning. It's not going to
tell you anything significant about the strength of the
hull.
I'd like to hear all about it when you get to that
point.
Jim T
In a message dated 1/18/2011 4:01:05 P.M. Central Standard Time,
JimToddPsub@aol.com writes:
Alan,
I considered doing that on the completed sub, but was
concerned about damage to gauges, etc. Even if you couldn't pull all the
way down to 0 psi on the bare bones sub, sounds like a good initial test
when you first have a sealed vessel and again after all the penetrations are
done.
Jim
In a message dated 1/18/2011 3:43:20 P.M. Central Standard Time,
alanjames@xtra.co.nz writes:
Hi,
I just started thinking about the idea of doing
a preliminary pressure test on my hull (when it's made)
by fitting a
vacuum pump to the outside. This would be done on the bare hull but with the
dome view port in place.
I would need to have a negative pressure of 250
psi.
Does this sound reasonable? Are there cheap
vacuum pumps that can produce this negative pressure or are
there
air pumps that I could modify & attach the
intake to the hull ???
Or has anyone done this?
Regards
Alan |