Hello Karl:
Stiffening rings can be
placed on the inside or on the outside of the vessel. The only
difference according to ASME Code (UG 30) is in the attachment of the rings
to the shell in terms of an intermittent weld. For outside rings, the weld
should not be no less than 1/2 the outside circumference on 6"
centers. For inside rings, the weld should be not less than 1/3 the
circumference on 6" centers.
The fillet weld size shall be the smallest of the
following: 1/4", the thickness of the vessel wall, or the thickness of
the stiffener at the joint In terms of material for rings, the
preference is toward using rings flame-cut from plate as opposed to rolled
material because of possible gaps between the ring and shell from
out-of-round rolled rings. Of course here they are probably referring
to vessels with a big O.D. as they refer to 1-2" possible gaps.
No such problem with our pityful small vessels(Carsten
excluded).
TTYL,
Big Dave
Hi Guys,
In contemplating the practicality of a
design concept I am thinking of, I need to know or be pointed in the
right direction, concerning the pro's & con's of external frames
versus internal.
No doubt, there are some
structural advantages for internal frames, hull welds are under
compression versus tension, and the external frames may need to be
heavier for external application. Maybe even a combination could work.
External frames and internal bulkheads, for example.
My intention is to create maximum internal
space for minimum volume and a double skin to create ballast pockets,
bottle storage and above all else, a streamlined hull, from a simple
cylindrical pressure hull. The outer skin, would be glass
fiber.
I'd also like to congratulate Carsten and
Dale on their progress. It is very encouraging to read about and view
the progress.
Thanks also for all the great scrubber info
Paul and the rest.
Regards,
Karl.