I have been out of engineering for two decades, but thinking of going back in. So I want to ask a question concerning somethings I did in the past. A simple question. I used to design vessels for low pressure. Under 5psi or less. We used to put torispherical heads. Often on tanks, where the heads were at the bottom and top of a vertical vessel. When we put manholes on the tanks I did not want the manhole cutting into or near the knuckle radius, thus weakening it. I know it is more complex than that. The manhole can add stiffness, but I wanted the knuckle radius to be unbroken. But the equations are nasty. So I would put the manhole in the center. of the head. (These heads were under 6 feet as a rule). A questions: 1) Is it wrong to put a manhole in the top center of a torisperical head?