Re: [PSUBS-MAILIST] Vent valves

[Jon Wallace <jonw@psubs.org>]

Hi Frank,

A properly trimmed sub should be either slightly buoyant, or minimally 
neutral with the main ballast free of air.  So even if the vents stuck 
open the sub should be able to surface by dumping emergency disposable 
weight and/or expelling any water in the VBT.  I'm not suggesting you 
don't have a good point anyway, and I agree with your premise justifying 
internal vent valves.  Of course, if the sub is intended to be 
negatively buoyant during operations or doesn't have emergency 
disposable weight, then you are absolutely correct in your concern about 
the vents getting stuck open.

Jon


>If the vent valves are outside the sub, and something happens to stop 
it's operation, you can't fill the tanks and float up.





************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003.  Your email address appears in our database
because either you, or someone you know, requested you receive messages
from our organization.

If you want to be removed from this mailing list simply click on the
link below or send a blank email message to:
	removeme-personal_submersibles@psubs.org

Removal of your email address from this mailing list occurs by an
automated process and should be complete within five minutes of
our server receiving your request.

PSUBS.ORG
PO Box 53
Weare, NH  03281
603-529-1100
************************************************************************
************************************************************************
************************************************************************