[PSUBS-MAILIST] Hp valves

Fri Jan 22 23:15:36 EST 2016

The original Kittredge arrangement is two SCUBA tanks inside the hull, with
ball valves allowing you to switch between them. On Snoopy I moved the
tanks outside, with independent HP lines into the hull. They had separate
hull stops, and from those were combined in a manifold. The HP lines had
check valves so that air could only enter the manifold but not back up, so
that if for whatever reason (say a blown tank valve O ring) you lost
pressure in one of the tanks, its check valve would prevent the manifold
and the second tank from emptying. In Shackleton I have reproduced the same
exact arrangement except everything but the gauges and BIBS has moved
outside.

Best,

Alec

On Fri, Jan 22, 2016 at 9:09 PM, Alan James via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> I don't know Brian, maybe Alec could answer that.
> G. L. have that golden rule that I quoted,
> Section 2 A.1..."Wherever expedient & feasible, submersibles are to be
> constructed in such a way
> that failure of any single component cannot give rise to a dangerous
> situation."
>    That seems a good rule of thumb to design from.
> Cheers Alan
>
>
>
>
> ------------------------------
> *From:* Brian Cox via Personal_Submersibles <
> personal_submersibles at psubs.org>
> *To:* Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> *Sent:* Saturday, January 23, 2016 2:41 PM
>
> *Subject:* Re: [PSUBS-MAILIST] Hp valves
>
> Alan,  Are the Kittridge subs all redundant in that respect?
>
> Brian
>
> --- personal_submersibles at psubs.org wrote:
>
> From: Alan James via Personal_Submersibles <
> personal_submersibles at psubs.org>
> To: Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> Subject: Re: [PSUBS-MAILIST] Hp valves
> Date: Fri, 22 Jan 2016 22:57:07 +0000 (UTC)
>
> Brian,
> just looked up the G.L. rules Section 9 piping systems, pumps &
> compressors.
> It says 1.2 Pipes which are led thriught the pressure hull are to be
> fitted with 2 shut off valves.
> One of which is to be fitted immediately at the hull wall.
>     In 3.3 it says " The compressed air supply is to be carried in at
> least 2 separate banks of receivers with the
> same total volume."
> Alan
>
>
>
> ------------------------------
> *From:* Alan James via Personal_Submersibles <
> personal_submersibles at psubs.org>
> *To:* Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> *Sent:* Saturday, January 23, 2016 11:31 AM
> *Subject:* Re: [PSUBS-MAILIST] Hp valves
>
> Brian,
> can you split the HP air in to two lines so you have two HP lines coming
> in.
> That way if one line failed you would have a back up. Also if a HP line
> ruptured
> or connection broke, then you would only have half the pressure in the
> hull.
> Inside my ambient I never see HP air, but I have two separate air systems
> & valves to use both simultaneously or separately.
> I am not sure what other psubbers do. This is bound to be covered in the
> Busby book.
>    I have heard reference to  subs being stuck in the mud through sitting
> on the bottom
> & coming up carrying a load of extra weight in the form of mud. I noticed
> in Carsten's
> video that he sat on the bottom & pivoted. I am guessing to let the divers
> out, but
> sounds like a good practice on a muddy sea bed.
> Alan
>
>
>
> ------------------------------
> *From:* Brian Cox via Personal_Submersibles <
> personal_submersibles at psubs.org>
> *To:* Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> *Sent:* Saturday, January 23, 2016 10:23 AM
> *Subject:* Re: [PSUBS-MAILIST] Hp valves
>
> Alan,   The air would most likely vent thru the hatch and then I'd be at
> whatever pressure the ambient water pressure would be .  If there was no
> air to surface I guess I'd have to bail.   I will have an additional tank
> outside the hull for filling the ballast however.  That will be for raising
> and lowering the sub with scuba while out side the sub.  I was thinking it
> would be kind of neat to set it on the bottom in about 30' water. That way
> I wouldn't have to anchor it !
>
> Brian
>
> --- personal_submersibles at psubs.org wrote:
>
> From: Alan James via Personal_Submersibles <
> personal_submersibles at psubs.org>
> To: Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> Subject: Re: [PSUBS-MAILIST] Hp valves
> Date: Fri, 22 Jan 2016 17:51:26 +0000 (UTC)
>
> Hi Brian,
> I questioned G.L. on a number of items in thier rules for submarines
> & there are some grey areas that you would have to argue the point over
> with an inspector.
> One general rule is that no one failure can cause a major event.
> If the pipe failed at that elbow & you couldn't stop the flow of HP air,
> what sort of pressure could you be left with in the hull?
> Would you be able to blow the ballast tanks if you lost your air
> from that failure or do you have a redundant air supply?
> Cheers Alan
>
>
>
>
>
> ------------------------------
> *From:* Brian Cox via Personal_Submersibles <
> personal_submersibles at psubs.org>
> *To:* Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> *Sent:* Saturday, January 23, 2016 6:34 AM
> *Subject:* Re: [PSUBS-MAILIST] Hp valves
>
> ABS says " as close as possible"  I guess I'm ok with a short nipple
> coming off a elbow.
>
> Brian
>
> --- personal_submersibles at psubs.org wrote:
>
> From: Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org
> >
> To: "PSubs " <personal_submersibles at psubs.org>
> Subject: [PSUBS-MAILIST] Hp valves
> Date: Wed, 20 Jan 2016 08:34:43 -0800
>
> Is there any distinction as to how close a HP shut off valve or check
> valve has to be to the hull penetration so as to meet ABS requirements?
> Can there be a short nipple between an elbow and the valve for instance?
>
> Brian Cox
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