[PSUBS-MAILIST] K-250 dome advice

[Sean T. Stevenson via Personal_Submersibles]

Pressure rating of the dome will be determined by the largest effective radius of curvature of the head. In a 2:1 semi-elliptical head, that radius occurs at the apex and the pressure rating is exactly half that of a hemispherical head at the same diameter. With a blown head, it is actually forming a spherical sector bounded at the dome diameter. You can work out where the center of curvature of that sector is based on geometry, but the pressure rating will be considerably less that that of a hemispherical dome. You must also account for thinning of the dome at the apex, as it is the minimum wall thickness which will apply to the pressure calc.

Sean

-------- Original Message --------
On Apr. 18, 2022, 07:56, Philippe Robert via Personal_Submersibles wrote:

> Hi All,
>
> I have an issue in the making of my k-250 dome. I asked for advice from some members in the past and now I have a new problem. The company that makes my dome cannot blow the dome to the specs (12 in height 24 in wide). So the max height that is acceptable is 9in to avoid the dome breaking when it is formed. So my question is ,is it acceptable to have a smaller height and I was wondering if the pressure rating of the dome will be ok.
>
> Thanks
>
> Philippe
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