Lift Lugs on Pressure Vessels

For starters, it would make sense to place the lifting lug at the top center of the vessel in the orientation it is intended to occupy. If this will overstress the head in a vertical vessel, another choice would be two lugs on the shell, placed 180° apart near the intended upper end. Whatever you do, it will depend on whether or not the vessel is pressurized when you lift it. If so, you must consider the combined lifting/pressure forces; if not, they can be treated separately.

You can use codecal to make the calcuation and design, it is limit to the lug weled to the shell...

The number, location and type of lifting/tailing lugs depend on the vessel size weight and the istallation specifics of your installation.

You could have a "wide short vessel" that would require many lugs on the top head or you could have a tall column that would require "lift trunions" on the top shell and one or two tailing lugs to get the vessel upright.

There is no easy answer to your question and a rigging/placement scheme depends on some subjective decisions as well as possible limitations of the the lifting equipment itself.

My opinion only