On Jul 2, 8:17*pm, Serene Vannoy > wrote:

> The insides of some pressure cookers have slightly curved bottoms, or at
> least that's what some book or other said when I was researching whether
> or not I could use my cooker as a canner.
>
> Serene

I think you must mean, "Bell Shaped", like some of the Fagor models;
the side of the pressure cooker where it joins the base flares out to
accommodate a large spoon or ladle for stirring. The bottom, however,
is still flat.

A pressure cooker with a rounded or bulging bottom is a good
indication that is was allowed to overheat to the point the metal
structure began to fail. I've seen this happen to thin walled aluminum
cookers, and it goes without say that any such pressure vessel should
be discarded.