more manholes in Pressure vessel skirts?

[mechmex]

Hi everyone.

I have a question, and hope to receive your feedback-
We have some pressure vessels with natural gas
about 4 mts diameter and 6 meter height, elliptical heads
these include skirts, about 20 mm in thickness.
Normally we include a 24 " manhole in the skirt.

Recently someone told us would be recommended to add a second manhole
in the skirt as a security issue, For example for fast venting in case of
a gas leak in the bottom of the vessel.

what are your toughts?

Are there goverments, laws or regulations in USA, ASME, API,etc
which states something about this? more manholes?

Thanks

 

[CaracasEC]

Read ASME VIII for the rules of construction for pressure vessel. However, i have seen a lot of pressure vessel but it has only one manhole at the skirt. Having two manholes would surely increase thickness and impractical.

 

[rb1957]

fortunatly everyone has resisted comments about "manholes" in "skirts" ...

untill now at least !?