reverse dished heads

[sme75]

I have received a project that calls for a flanged and reverse dished head. Can anyone point me to a reference that talks about the design of these? Are they intended to be used in a pressure/vacuum situation or are they typically only used in atmospheric applications? Thanks for any help you can give.

 

[JStephen]

Seems like I have seen these used on sandblast pots, where the reversed shape formed a funnel on the top of the tank. So I would assume they CAN be used for pressure.

 

[rzrbk]

I have seen these used on chlorine cylinders.

Not sure, but would guess the reason in this case to be for protection of the valves inserted in the head during shipping. They don't protrude past the shell and would be less likely to get knocked off.

 

[ggarciae]

It's quite usual in pressure vessels for textile industry.
A reference for calculations is AD-Merkblatt B4 Dished ends.
Depending on combinations of pressure/vacuum and reversed/not-reversed dish shape may be neccesary to change signs +/- of a pair of moments.

Hope this helps

Regards from Barcelona
G. García