JT,
Pressure vessel quality steel is referred to a PVQ
plate. Don't quote me on this but I think it has a finer grain structure
then ASTM-A36. The one I'm using, ASTM-516 Grade 70. I believe it
has better cold temperature properties.
My recommendation to use PVQ plate steel rather
then steel pipe is also for dimensional tolerance. Being a pipe welder,
I'm sure you agree that large diameter pipe isn't true round. It's near
and can be pulled into shape if needed. A hull is in compression, not
tension as pipe is in it's normal use. If a hull isn't true round, the
forces acting on it are out of balance and it will flatten. Pipe, with
internal pressure, doesn't have this problem. A good fab shop will be able
to role a hull to with in a sixteenth inch of true round. The rest is done
with the framing.
Dan H.
----- Original Message -----From: John T. McCrackenSent: Friday, February 20, 2004 11:14 PMSubject: Re: [PSUBS-MAILIST] Re: SupliesI have built, modified and repaired a few pressure vessels over the years and work with high pressure piping regularly and I have never heard the term "pressure vessel quality material". Vessels are made from a WIDE range of materials and pipe is too, depending on a lot of factors. I would venture that there is no grade of steel available for building a vessel that is not available as pipe. Pipe is inevitably attached to a vessel, that pipe equals or exceeds the mechanical properties of the vessel itself. Could you be specific in exactly what steel you are suggesting?JTMcC.----- Original Message -----From: Dan H.Sent: Wednesday, February 18, 2004 6:28 AMSubject: Re: [PSUBS-MAILIST] Re: SupliesMarcus,Sorry but I don't have any help for you with sources in your area.Have you found seamless pipe as large as you need for a hull??? I'm pretty sure any pipe you find that big is made of welded plate anyway.End caps are made to size but you have to pick out a size that is available off the shelf to get it at a price you can afford. Tooling charges are high for special sizes. Contact a supplier to find what they have as standards. You probably should consider building out of pressure vessel quality material since it's not much more then common carbon steel anyway.Dan H. USA----- Original Message -----From: Greeff, Marius (M)Sent: Wednesday, February 18, 2004 3:16 AMSubject: RE: [PSUBS-MAILIST] Re: SupliesIf one roles a piece of plate it will have a weld compared to seemless pipe, would a piece of seemless pipe not be the stronger solution? Endcaps can be made to size unless I have been wrongly informed. I found that a lot of the suppliers mentioned are Amerian based, is there any one around South Africa in this group with advice as to where they got there material and gauges?Marius-----Original Message-----
From: Dan H. [mailto:jmachine@adelphia.net]
Sent: 18 February 2004 03:56
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Re: SupliesMark,Why use pipe? Why not design what you need and have the hull rolled out of plate. You'd have better control on the trueness of the shape and you could use pressure vessel quality material.Dan H.----- Original Message -----From: Mark WoodwardSent: Tuesday, February 17, 2004 8:17 PMSubject: [PSUBS-MAILIST] Re: Suplies
Hi all,I have been working on my design for my personal sub. But I am having a problem find materials. Such as steel pipes. To which my design is based on.Any Help would be great!!Thanks, Mark...
Mark Woodward![]()
Do you Yahoo!?
Yahoo! Finance: Get your refund fast by filing online
NOTICE: Please note that this eMail, and the contents thereof, is subject to the standard Sasol eMail disclaimer which may be found at: http://www.sasol.com/disclaimer
If you cannot access the disclaimer through the URL attached and you wish to receive a copy thereof please send an eMail to disclaimer@sasol.com
This email was scanned and cleared by NetIQ MailMarshal.