Pressure vessel in a (near) vacuum

[CaptainofIron]

I don't know if its daylight savings or what, but I just can't seem to wrap my head around this analysis.

There is a polycarbonate hemispherical head with 8 psi in a near vacuum environment (2.8 torr)

Im trying to figure out what the minimum thickness is for the head.

The shell is super thick and seamless so I am not worried about it.

The OD is 3.5"

 

[M Quack]

Just add 1 bar to the pressure inside the head to account for the extra force due to the vacuum outside.