[PSUBS-MAILIST] O2 tanks (via Personal_Submersibles)

Sun Jul 2 13:30:01 EDT 2017

I was just going to point this out. You need a fully dynamic / non-linear solver to model behaviour beyond yield, which the companion applets to the CAD packages are not.

The standard ABS equations will do fine for design - they are derived from the ASME Boiler and Pressure Vessel Code, Section 8. The greater problem is probably obtaining drawings or accurate measurements of the gas cylinder wall thickness and head geometry.  

If you really want externally mounted gas storage for a deep diving sub, you are probably looking at custom vessels anyway. RMS Titanic is on the seafloor at 12,500 fsw. The pressure at that depth is 5700 psi or so - guaranteed to fail even a full SCUBA cylinder at 3000 psi internal.

Sean

On July 2, 2017 9:45:01 AM PDT, Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>Jerry, Inventor FEA base module is linear model only.  It will only
>solve
>one of the three possible failure modes and not either of the buckling
>modes,
>
>Cliff
>
>On Sun, Jul 2, 2017 at 9:19 AM, Jerry Koontz via Personal_Submersibles
><
>personal_submersibles at psubs.org> wrote:
>
>> Autocad Inventor has the FEA tool built in and works really well.
>>
>> ----- Original Message -----
>> From: "via Personal_Submersibles" <personal_submersibles at psubs.org>
>> To: "personal submersibles" <personal_submersibles at psubs.org>
>> Sent: Sunday, July 2, 2017 12:47:36 AM
>> Subject: Personal_Submersibles Digest, Vol 49, Issue 3
>>
>> Send Personal_Submersibles mailing list submissions to
>>         personal_submersibles at psubs.org
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>>        
>http://www.whoweb.com/mailman/listinfo.cgi/personal_submersibles
>> or, via email, send a message with subject or body 'help' to
>>         personal_submersibles-request at psubs.org
>>
>> You can reach the person managing the list at
>>         personal_submersibles-owner at psubs.org
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of Personal_Submersibles digest..."
>>
>>
>> Today's Topics:
>>
>>    1. Re: O2 tanks (via Personal_Submersibles)
>>    2. Re: O2 tanks (hank pronk via Personal_Submersibles)
>>    3. Re: O2 tanks (Alan via Personal_Submersibles)
>>
>>
>>
>----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Sat, 1 Jul 2017 18:59:23 -0500
>> From: via Personal_Submersibles <personal_submersibles at psubs.org>
>> To: Personal Submersibles General Discussion
>>         <personal_submersibles at psubs.org>
>> Subject: Re: [PSUBS-MAILIST] O2 tanks
>> Message-ID: <57782A8F-9754-4039-ADC3-58C64B181810 at gmail.com>
>> Content-Type: text/plain; charset="utf-8"
>>
>> Most of the FEA packages associated with 3-d modeling software use a
>> linear model.  You would need an FEA tool that can model buckling to
>study
>> this.  An alternative is to use the ABS stress analysis spreadsheet
>with no
>> stiffeners.  This would give a conserative crush depth.
>>
>> Cliff
>>
>>
>> Cliff Redus
>>
>> > On Jul 1, 2017, at 2:27 PM, Scott Waters via Personal_Submersibles
><
>> personal_submersibles at psubs.org> wrote:
>> >
>> > I am unsure of the depth rating of an empty scuba tank. It could be
>> easily found out on a solidworks simulation.
>> > Thanks,
>> > Scott
>> >
>> >
>> >
>> > Sent from my U.S. Cellular? Smartphone
>> >
>> > -------- Original message --------
>> > From: hank pronk via Personal_Submersibles
><personal_submersibles at psubs.
>> org>
>> > Date: 7/1/17 12:34 PM (GMT-05:00)
>> > To: Personal Submersibles General Discussion <
>> personal_submersibles at psubs.org>
>> > Subject: Re: [PSUBS-MAILIST] O2 tanks
>> >
>> > Thanks' Scott,Do you know what the max depth rating for an empty
>Scuba
>> O2 tank is.  I suppose you could increase the rating by using only
>part of
>> the volume and leave pressure inside them.  A sub could carry several
>in
>> that case since they are close to neutral buoyant.  Hank
>> >
>> >     On Saturday, July 1, 2017 8:25 AM, Scott Waters via
>> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> >
>> >
>> > Hank,Alvin has all the O2 supply internally. Pisces has the mission
>O2
>> internally and emergency supply externally in special steel cylinders
>that
>> are pressure tested to 1.25 max depth while empty.Thanks,Scott Waters
>> >
>> >
>> > Sent from my U.S. Cellular? Smartphone
>> > -------- Original message --------From: hank pronk via
>> Personal_Submersibles <personal_submersibles at psubs.org> Date: 7/1/17
>9:59
>> AM (GMT-05:00) To: Personal Submersibles General Discussion <
>> personal_submersibles at psubs.org> Su
>> > _______________________________________________
>> > Personal_Submersibles mailing list
>> > Personal_Submersibles at psubs.org
>> > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL:
><http://www.whoweb.com/pipermail/personal_submersibles/attachments/
>> 20170701/1d624f94/attachment-0001.html>
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Sun, 2 Jul 2017 01:13:38 +0000 (UTC)
>> From: hank pronk via Personal_Submersibles
>>         <personal_submersibles at psubs.org>
>> To: Personal Submersibles General Discussion
>>         <personal_submersibles at psubs.org>
>> Subject: Re: [PSUBS-MAILIST] O2 tanks
>> Message-ID: <1987652214.3245144.1498958018223 at mail.yahoo.com>
>> Content-Type: text/plain; charset="utf-8"
>>
>> Cliff,That is exactly what I did, I put the tank specs in the
>unstiffened
>> cylinder program. ?The only problem is, I can not find the exact
>material
>> the steel tanks are made from. ?I am assuming same steel and gives a
>good
>> estimate.Thanks CliffHank
>>
>>     On Saturday, July 1, 2017 6:05 PM, via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>>
>>  Most of the FEA packages associated with 3-d modeling software use a
>> linear model. ?You would need an FEA tool that can model buckling to
>study
>> this. ?An alternative is to use the ABS stress analysis spreadsheet
>with no
>> stiffeners. ?This would give a conserative crush depth.
>> Cliff
>>
>> Cliff Redus
>> On Jul 1, 2017, at 2:27 PM, Scott Waters via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>>
>>
>> I am unsure of the depth rating of an empty scuba tank. It could be
>easily
>> found out on a solidworks simulation.Thanks,Scott
>>
>>
>> Sent from my U.S. Cellular? Smartphone
>> -------- Original message --------From: hank pronk via
>> Personal_Submersibles <personal_submersibles at psubs.org> Date: 7/1/17
>> 12:34 PM (GMT-05:00) To: Personal Submersibles General Discussion <
>> personal_submersibles at psubs.org> Subject: Re: [PSUBS-MAILIST] O2
>tanks
>> Thanks' Scott,Do you know what the max depth rating for an empty
>Scuba O2
>> tank is. ?I suppose you could increase the rating by using only part
>of the
>> volume and leave pressure inside them. ?A sub could carry several in
>that
>> case since they are close to neutral buoyant. ?Hank
>>
>> ??? On Saturday, July 1, 2017 8:25 AM, Scott Waters via
>> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>
>>
>>  Hank,Alvin has all the O2 supply internally. Pisces has the mission
>O2
>> internally and emergency supply externally in special steel cylinders
>that
>> are pressure tested to 1.25 max depth while empty.Thanks,Scott Waters
>>
>>
>> Sent from my U.S. Cellular? Smartphone
>> -------- Original message --------From: hank pronk via
>> Personal_Submersibles <personal_submersibles at psubs.org> Date: 7/1/17
>9:59
>> AM (GMT-05:00) To: Personal Submersibles General Discussion <
>> personal_submersibles at psubs.org> Su
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>>
>>
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL:
><http://www.whoweb.com/pipermail/personal_submersibles/attachments/
>> 20170702/8f335ce9/attachment-0001.html>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Sun, 2 Jul 2017 17:47:43 +1200
>> From: Alan via Personal_Submersibles
><personal_submersibles at psubs.org>
>> To: Personal Submersibles General Discussion
>>         <personal_submersibles at psubs.org>
>> Subject: Re: [PSUBS-MAILIST] O2 tanks
>> Message-ID: <99C62E5C-67D0-4A55-8CBD-F816E8A1586C at yahoo.com>
>> Content-Type: text/plain; charset="utf-8"
>>
>> Cliff, ( or anyone)
>> I was thinking of ways of making my one person sub idiot proof with
>> regard to the turning on of the O2 supply. If I let anybody dive it I
>won't
>> be in there to oversee.
>> My ideas are to have a switch under the seat ( as they have on ride
>on lawn
>> mowers) & a hatch closure switch ( which is required by G.L. ) linked
>to
>> the O2 system so that when both switches are closed ( pilot seated &
>> hatch closed) the O2 feed system is activated. This will be the
>solenoid
>> top
>> up part of the O2 system. A sign & maybe audible voice will say "
>Turn on
>> Oxygen
>> valve". So the system will be like the DW O2 add system where there
>is a
>> minimal amount of O2 constantly flowing but the balance flows in from
>a
>> solenoid
>> valve activated by O2 level readings.
>> The CO2 scrubber could also be linked.
>> Any thoughts on this?
>> Thanks Alan
>>
>>
>>
>>
>> Sent from my iPad
>>
>> > On 2/07/2017, at 1:13 PM, hank pronk via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>> >
>> > Cliff,
>> > That is exactly what I did, I put the tank specs in the unstiffened
>> cylinder program.  The only problem is, I can not findways of  the
>exact
>> material the steel tanks are made from.  I am assuming same steel and
>gives
>> a good estimate.
>> > Thanks Cliff
>> > Hank
>> >
>> >
>> > On Saturday, July 1, 2017 6:05 PM, via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>> >
>> >
>> > Most of the FEA packages associated with 3-d modeling software use
>a
>> linear model.  You would need an FEA tool that can model buckling to
>study
>> this.  An alternative is to use the ABS stress analysis spreadsheet
>with no
>> stiffeners.  This would give a conserative crush depth.
>> >
>> > Cliff
>> >
>> >
>> > Cliff Redus
>> >
>> >> On Jul 1, 2017, at 2:27 PM, Scott Waters via Personal_Submersibles
><
>> personal_submersibles at psubs.org> wrote:
>> >>
>> >
>> >
>> > I am unsure of the depth rating of an empty scuba tank. It could be
>> easily found out on a solidworks simulation.
>> > Thanks,
>> > Scott
>> >
>> >
>> >
>> > Sent from my U.S. Cellular? Smartphone
>> >
>> > -------- Original message --------
>> > From: hank pronk via Personal_Submersibles
><personal_submersibles at psubs.
>> org>
>> > Date: 7/1/17 12:34 PM (GMT-05:00)
>> > To: Personal Submersibles General Discussion <
>> personal_submersibles at psubs.org>
>> > Subject: Re: [PSUBS-MAILIST] O2 tanks
>> >
>> > Thanks' Scott,Do you know what the max depth rating for an empty
>Scuba
>> O2 tank is.  I suppose you could increase the rating by using only
>part of
>> the volume and leave pressure inside them.  A sub could carry several
>in
>> that case since they are close to neutral buoyant.  Hank
>> >
>> >     On Saturday, July 1, 2017 8:25 AM, Scott Waters via
>> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> >
>> >
>> > Hank,Alvin has all the O2 supply internally. Pisces has the mission
>O2
>> internally and emergency supply externally in special steel cylinders
>that
>> are pressure tested to 1.25 max depth while empty.Thanks,Scott Waters
>> >
>> >
>> > Sent from my U.S. Cellular? Smartphone
>> > -------- Original message --------From: hank pronk via
>> Personal_Submersibles <personal_submersibles at psubs.org> Date: 7/1/17
>9:59
>> AM (GMT-05:00) To: Personal Submersibles General Discussion <
>> personal_submersibles at psubs.org> Su
>> >>
>> >> _______________________________________________
>> >> Personal_Submersibles mailing list
>> >> Personal_Submersibles at psubs.org
>> >> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> >
>> > _______________________________________________
>> > Personal_Submersibles mailing list
>> > Personal_Submersibles at psubs.org
>> > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> >
>> >
>> > _______________________________________________
>> > Personal_Submersibles mailing list
>> > Personal_Submersibles at psubs.org
>> > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL:
><http://www.whoweb.com/pipermail/personal_submersibles/attachments/
>> 20170702/1d789b04/attachment.html>
>>
>> ------------------------------
>>
>> Subject: Digest Footer
>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.whoweb.com/mailman/listinfo.cgi/personal_submersibles
>>
>>
>> ------------------------------
>>
>> End of Personal_Submersibles Digest, Vol 49, Issue 3
>> ****************************************************
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20170702/6a3dc01f/attachment-0001.html>