I saw this post, and figured it was for some old heat pipe tubing which (from foggy memory) used to have grooves cut to drain the condensate so drop-wise instead of the less efficient film type heat transfer coefficient mechanism could be used.
There are, I think, three practical ways to make it:
1) Extrusion 2) Groove cutting similar to how rifling is cut in gun barrels. 3) Forming using a button die or probably a stepped broach. Some gunmanufacturers (e.g. Marlin) use the button die method method to form rifling, however such a deep groove would require a series of dies, or the stepped broach, and probably an external clamping mandrel to stop the pipe tearing.
A fourth way is hammer/roll forming the tube onto an internal grooved mandrel, but I think a high level of prior experience would be required to get this to work.
If the tube is grooved for heat transfer try googling Hudson Products Corporation; if they dont have a suitable product, they may be able to point you in the right direction.
Unless you have a suitably equipped shop, look at buying, not making.
Cheers
Steve McKenzie
-----Original Message-----
From: Paul Bowers [mailto:pbowers@pipingdesign.com]
Sent: Thursday, January 08, 2004 4:52 PM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] IN WHICH METHOD IT IS EASY MANUFACTURE
Just for reference, "we" (an unnamed cold box manufacturing company) used to roll Sch.10s in the shop on a regular basis for low pressure cryogenic service. It was always welded and properly shop and field tested before use. Threading a 2mm wall?
Paul
> custom fab of pipe seems an awful lot of work and added expense to me.
> Perhaps in some places that is the standard way to do things (I know
> that structural steel was always custom fabricated in any shape and
> dimension in Russia, so perhaps pipe and tubing is always custom in some
> places). The dimensions are awfully close to standard tubing (12.5mm or
> 1/2 inch) - the wall thickness is on the thin side, so perhaps you have
> to settle for slightly thicker or slightly thinner, depending on your
> process and structural needs. I would be nervous about threading
> anything this thin walled. welding thinwall tubing is usually less work
> and less expensive than threading it.
>
> ... Bruce D. Bullough ...
> Sebesta Blomberg & Associates
> 2381 Rosegate
> Roseville, MN 55113 USA
> 651-634-7344 direct
> 651-634-7400 FAX
> www.sebesta.com
>
> -----Original Message-----
> From: vgopi1982 [mailto:vgopi1982@yahoo.co.in]
> Sent: Tuesday, January 06, 2004 12:42 AM
> To: PipingDesign@yahoogroups.com
> Subject: [PipingDesign] IN WHICH METHOD IT IS EASY MANUFACTURE
> [bcc][faked-from][bayes]
>
>
> hi
>
> WISH YOU HAPPY NEW YEAR
>
> I want to fabricate the pipe which
>
> OD IS 14mm
> ID IS 12mm
> NO OF GROOVEES IS 28
> ROOVE THICKNESS IS .5mm
> WIDTH IS 1.1mm
>
> IN WHICH METHOD IT IS EASY MANUFACTURE?
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