pressure vessel 3

Give us a sketch to make sure we're all talking about the same thing.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

You're welcome.

Over my career I've reviewed drawings of hundreds of pressure vessels from dozens of different manufacturers, but not once have I seen nozzle bolt holes straddle centerlines in the needlessly complicated manner shown on CuMo's sketch. The bolt holes for offset nozzles typically straddle centerlines that are parallel to the principal axes of the vessel.


-Christine

Yes, this ^

The problem with sloppy work is that the supply FAR EXCEEDS the demand

For typical vessels- assume straddling principle axes. This assumes piping coming up to the tank is aligned with or at cross angles to those axes.
Large storage tanks- typically straddle radial lines, not principle axes.
Medium storage tanks in congested plant environment, or small storage tanks- better ask.