On Mon, 12 Jun 2000, Don Ward wrote:

> Now I have a follow-up to my own question.  Do I need tools to change
> a tank?  I am under the impression that the tank(s) is affixed with
> bands and bolts

Short answer - No.

Double cylinder setups use bands and bolts to hold the cylinders together.
The same bolts that affix the bands to the cylinders then serve to attach
the assembly to the backplate, usually with wing nuts. No tools are needed
to remove the backplate and wing from the doubles, and one normally does
not disassemble the doubles (except to service them) - in fact, with a
manifold connecting them, you'd have to drain them completely to do so.

With a single cylinder, an adaptor is used. This is nothing more than a
thin piece of aluminum, stainless steel or plastic about 3" wide and 14"
long that has two cam straps attached to it to hold the cylinder. The
adaptor in turn mounts to the backplate using bolts and wing nuts. Again,
no tools are required. Changing the cylinder is accomplished in exactly
the same way as it is with any other BC with two cam straps.

The adaptors do vary a little in style. The OMS stainless steel version
has the bolts permanantly mounted to it, and it has a fairly low cross
section so the cylinder is held as close as possible to the backplate. The
Dive-Rite ABS plastic unit is similar in cross section, but the bolts are
loose and therefore easily replaced if they are damaged. The Halcyon
aluminum adaptor is made of aluminum "U" channel, so it holds the cylinder
farthest away from the backplate of the three adaptors. It also has the
bolts loose.

All of these backplates and adaptors have the cylinder mounting holes
spaced 11" apart - that is a standard that makes all of these

Art Greenberg
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