[PSUBS-MAILIST] Heads Question

Sat Sep 16 13:14:52 EDT 2017

 Greg,The problem with calling it a vacuum tank is the sphericity.  ASME is not as fussy as ABS for sphericity, and if you ask for the proper sphericity the cat is out of the bag.  Hank
    On Saturday, September 16, 2017, 10:50:57 AM MDT, james cottrell via Personal_Submersibles <personal_submersibles at psubs.org> wrote:  

 Hi David,
In my experience it was cheaper and faster to hire an ASME tank fabricator to produce a steel cylinder with the head (or heads) welded on. Mine came machine welded with an ASME code stamp. If your design will feature external frames, ask them for both heads welded on. If your design will feature internal frames (done later) ask them to weld one end only. This will be cheaper in the long run and better built. It's hard to beat pressure vessel code machine welding. Specify NO backing strips.
Another tip- call it a "vacuum tank".
Greg Cottrell

      From: David Colombo via Personal_Submersibles <personal_submersibles at psubs.org>
 To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
 Sent: Saturday, September 16, 2017 12:20 PM
 Subject: Re: [PSUBS-MAILIST] Heads Question

Hi Alec, I just spoke with the company that Roberto mentioned here in California to place an order for dished head for the SeaQuestor. I will be using the 36"OD x .375 A516-70 steel what they call Elliptical 2:1 Ratio ASME Code Type. It comes with a 2" flange which is really a 36" od ring shape as part of the forming. This would mate up to the 36"OD first hull section. I'm thinking that this would give me the best welding condition with two matched surfaces that I would bevel for full pen welding. I'm curious why not to have the flange?   My cost here is $480.00 + $96 to have it shipped to northern California from southern California. even though its only a nine hour drive one way, I think my time would be worth more than $5 hr to pick it up. LOL Unless of course its cheaper in Canada (Hank), I might make the trip and could serve as support crew for the Gamma. Any thoughts out there from fellow Psubers would be appreciated.

Best Regards,
David Colombo

804 College Ave
Santa Rosa, CA. 95404
(707) 536-1424
www.SeaQuestor.com

On Fri, Sep 15, 2017 at 2:28 PM, Alec Smyth via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

Ugh, mental typo. I meant "un-beveled" and "bevel them yourself", not "un-flanged" and "flange them yourself".
!!!!!!!
On Fri, Sep 15, 2017 at 5:25 PM, Alec Smyth <alecsmyth at gmail.com> wrote:

Hi Roberto,
I believe the short description for what you need is flanged, beveled, and code. You could get them unflanged, but it takes quite a while to make a flange with an angle grinder. The flanges if I recall are 2". Do set up a project page or something so we can follow progress!

Best,
Alec
On Fri, Sep 15, 2017 at 5:07 PM, roberto alvarez via Personal_Submersibles <personal_submersibles at psubs.o rg> wrote:

Hi, lost the plans cd for the k250, i am  interested in the  head selection, i found a seler in california and have flanged ,beveled ,code, non code,
Will apreciate your support in this ( until i found the plans cd )
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