[PSUBS-MAILIST] Pressure Test

Mon Jul 3 22:19:41 EDT 2017

Hank, the acrylic will not carry any of the hull hoop stresses - it simply isn't strong enough to do so. You have to analyze the opening as if the acrylic isn't there, which means you need sufficient reinforcement around the opening to carry the stress that would otherwise have been carried by the steel that was removed.  The stress in the reinforcement will be greater than the nominal shell stress because of the stress concentration resulting from the new geometry.

In short, you can determine the required acrylic window thickness, and design a window frame accordingly, but that alone does not determine how much steel needs to be in that frame. That is instead determined by the shell stresses that must necessarily be routed around - not through - the opening.

Sean

On July 3, 2017 5:32:36 PM PDT, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>Greg,I am having trouble understanding why Ron says you need a hell of
>a lot more material that 100% rule for a window opening.  My logic is
>as follows, if you remove a conical section out of a heavy wall sphere
>and the angle intersects the centre of the sphere, you can glue it back
>in and the hull has not lost strength in that area.  Now if you replace
>that with an identical section of acrylic, it will not work.  To my
>mind the reason it will not work is, the acrylic will compress and the
>mass is no longer sufficient to carry the load along the load path into
>the hull.  Now, if the acrylic is thicker, it will handle the pressure
>without failing and it can compress and have enough strength  to carry
>the load to the frame .  The window port frame need only transfer the
>force from the extra thickness into the load path.  In short, to me,
>the port frame is only supporting the extra acrylic thickness and
>transferring the force into the hull.  Hank 
>
>On Monday, June 26, 2017 6:58 PM, james cottrell via
>Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
>
>Here is a pic of Ron piloting the sub at 850
>meters.http://ocean-innovations.net/OceanInnovationsNEW/Global%20Ocean%20Design/ont_part3_god.pdf
>
>Ron told me that the rule about replacing the same amount of material
>removed from the viewport opening was wrong -"you need a hell of a lot
>more" were his exact words. He also used a different steel for the
>hatch (300 M). He said that the best lube for the port was a "dry
>glide" spray from  CRC. Contrary to popular thinking, vacuum or silcone
>grease stores up pressure and then releases it with a BANG! He really
>knows his stuff...
>There are a few good drawings of the DSC hull online and they might
>come in handy since you will be building something very similar.
>Greg
>
>From: hank pronk via Personal_Submersibles
><personal_submersibles at psubs.org>
>To: Personal Submersibles General Discussion
><personal_submersibles at psubs.org> 
> Sent: Monday, June 26, 2017 8:28 PM
> Subject: Re: [PSUBS-MAILIST] Pressure Test
>  
>Greg,Being a non engineer, I am a copy cat, that is how I built
>Elementary 3000, I listened to what Sean had to say, I studied Scotts
>P6 and even duplicated Scott's P6 port and frame.  You could take my
>port and fit it in Scotts sub.  I stole the port in the Hatch Idea.
> The only idea I have had is to glue and bolt the whole thing together.
> Trieste has a second sphere from new and it is made from 3 perfectly
> machined sections.Hank 
>
>On Monday, June 26, 2017 5:56 PM, james cottrell via
>Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
>
>I had the pleasure of meeting him at Nat Geo when Jim C was there with
>the sub and gave a talk. Ron is THE MAN! Probably the most
>knowledgeable DEEP sub builder today. If you're serious about Titanic,
>find out EVERYTHING you can about the way he put that sub together.One
>thing he told me was never used silicone grease on a viewport and added
>that  "it is the worst". Through testing, Ron discovered that a lot of
>accepted standards and practices about deep sub construction are
>actually not correct.
>Greg
>
>From: hank pronk via Personal_Submersibles
><personal_submersibles at psubs.org>
>To: Personal Submersibles General Discussion
><personal_submersibles at psubs.org> 
> Sent: Monday, June 26, 2017 7:32 PM
> Subject: Re: [PSUBS-MAILIST] Pressure Test
>  
>Greg,Do you know Ron personally, were you involved with the port?Hank 
>
>On Monday, June 26, 2017 4:25 PM, james cottrell via
>Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
>
> Hank,
>The steel that Ron choice was actually much stronger than HY-100. Here
>is an article you might find interesting-
>http://www.ansys.com/-/media/Ansys/corporate/resourcelibrary/article/AA-V6-I3-Deep-Dive.pdf
>
>
>Greg
>
>From: hank pronk via Personal_Submersibles
><personal_submersibles at psubs.org>
>To: Personal Submersibles General Discussion
><personal_submersibles at psubs.org> 
> Sent: Monday, June 26, 2017 5:57 PM
> Subject: Re: [PSUBS-MAILIST] Pressure Test
>  
>Greg,Thank you for the acrylic offer, that would be great, of coarse I
>will be looking to you for annealing.  The CNG sphere at 48 in ID and
>3.25 in thick  could do it but it would be past the safe woking
>pressure witch is 4444.8 psi just shy of 10,000 feetThe sphere your
>talking about was probably exotic steel like HY-100Edmonton Exchanger
>did say they would press a HY steel head for me but foam is cheaper I
>think.Pity about the CNG sphere because they have a life of 300 years
>and I can pick one up in Texas for 8KHank 
>
>On Monday, June 26, 2017 3:20 PM, james cottrell via
>Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
>
> Hank,
>I'm surprised to hear you say that the CNG sphere is too light. My
>"seat of the pants" engineering tells me that a CNG sphere would be
>plenty. Are you sure its too light? If memory serves me correctly, the
>sphere that Ron Allum made was 42" OD x 2.5" thick gun barrel steel and
>had a 1.4/1 safety factor at 38,000 ft.
>What thickness acrylic do you need for the port? I'll donate a piece of
>4" to the cause if that will help.
>Greg
>
>From: hank pronk via Personal_Submersibles
><personal_submersibles at psubs.org>
>To: Personal Submersibles General Discussion
><personal_submersibles at psubs.org> 
> Sent: Monday, June 26, 2017 4:10 PM
> Subject: Re: [PSUBS-MAILIST] Pressure Test
>  
>Greg, I do not have a plan for getting on site.  I have a plan to get
>there, East Coast that is.  I can haul it cross country myself.Right
>now it is a dream really, not a plan.  But Elementary 3000 started that
>way.  I do have it mostly figured out, and I have an EFA guy lined up
>through Karl Stanley.   I will have two heads pressed and machined at
>Edmonton Exchanger in Edmonton Alberta.  My original CNG sphere plan is
>to light.  I think the getting on site part will evolve, I am sure
>money will make that happen easily.Thanks' for calling it "interesting"
>and not ridiculous. ;-)Hank 
>
>On Monday, June 26, 2017 12:01 PM, Alan via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
> 
>
>Thanks David,I get 7000 lumens. Have a dimmer control for it buthaven't
>tried it yet.Alan
>
>Sent from my iPad
>On 27/06/2017, at 3:08 AM, David Colombo via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>
>
>Hi Alan, Looks great!, what Lumens did you get with this design?
>
>
>Best Regards,
>David Colombo
>
>804 College Ave
>Santa Rosa, CA. 95404
>(707) 536-1424
>www.SeaQuestor.com
>
>
>On Mon, Jun 26, 2017 at 4:48 AM, hank pronk via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>
>Alan,That really turned out nice, how did you mould the polyurethane?
>that stuff sticks like mad. I would leave the white gasket, it looks
>fine.  Either the gasket thickness is not even or the seat is not
>perfectly matched to the Lenz. 
>
>On Sunday, June 25, 2017 10:30 PM, Alan via Personal_Submersibles
><personal_submersibles at psubs. org> wrote:
> 
>
>Pressure tested my light to 1000 psi for an hour using the water
>blaster 
>& no leaks! I didn't have a pressure relief valve in the system as I do
>with
>my air pressure set up & it was a pain getting the chamber lid off. I
>had
>thought the water blaster would have leaked a bit of pressure but it
>didn't.
>The sealing system for the wires was a 3 layered process; encapsulating
>the
>wires in the epoxy, then coating the insulation for an inch up from
>where they came 
>out of  the epoxy, & over the epoxy with a 2 part heat activated pvc
>glue that 
>they use on inflatable boats. This glue worked a lot better on the pvc
>insulation
>than several others I tried like E61000 (supposed to be better than
>shoe goo),
>3M 5200 & polyurethane.
>Over this, to tidy it up & act as a cable support, I moulded
>polyurethane.
>In the attached photos the white ptfe gasket that the lens sits on
>looks wet
>but it is just the compression of the lens against the gasket. I don't
>like this
>from a cosmetic point & may change it. The 2 objects with the light are
>the
>male mould for the polyurethane cable support & the silicone mould for
>the 
>same.
>Alan
>
>
>Sent from my iPad__________________________ _____________________
>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
>
>_______________________________________________
>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
>
>
>   
>
>|  | Virus-free. www.avast.com  |
>
>_______________________________________________
>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
>
>
>   _______________________________________________
>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
>
>
>   _______________________________________________
>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/20170703/ac11373b/attachment.html>