User manual

Table Of Contents
Glass Spheres
The two glass spheres mounted in the frame together provide 20 kg (44lbs) of buoyancy
to balance the weight of the pressure housings and their contents. The spheres are borosilicate
glass (highly durable, low expansion glass) with a 30.5cm (12”) outside diameter and are tested at
McLane to 10360 psi (7000 meters).
IMPORTANT
After each deployment, inspect the spheres for signs of fatigue caused by repeated pressure
cycling. Refer to Chapter 4, “Maintenance and Storage” for details on sphere maintenance.
Figure 2-7: Glass Spheres
The top faired end cap must be off to remove the upper sphere (once the end cap is
released the sphere is free to move). Unscrew the flat-head nylon bolts securing the edge of the
end cap to the top rib. To remove the lower sphere, remove the left and right halves of the skin
and disassemble the upper portion of the frame. Replace the spheres with the equator aligned to
the ribs of the MMP.
IMPORTANT
The original spheres can be reinstalled, however, installing new spheres requires re-ballasting to
ensure a precise ballast calculation. McLane offers a re-glass, re-ballast service.
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