We've had this conversation before. Hull stop valves are for gas and fluid penetrations (and for throttling rate controlled manipulators). I've had glass filled penetrators so busted you couldn't have done more with a shop hammer, but I have never had one leak through. Never. The real issue is the mating surface and the o-ring. Good annual service should stay ahead of that problem. Beyond that, it's just how belt-and-suspenders you want to go.Vance
-----Original Message-----
From: kocpnt tds.net <kocpnt@tds.net>
To: personal_submersibles@psubs.org
Sent: Sat, Jan 23, 2010 5:04 pm
Subject: [PSUBS-MAILIST] Thru-hulls
This question is for the more experienced psubbers out there.I know SOP is to put a valve inside of any hull penetration. If using a professionally built thru-hull (SubConn) is this still important in your opinion.Best Regards,Jim K