Opening in Skirts of Pressure Vessel

What codes and specifications are in effect?

What country are you in?

Does the vessel contain liquid or gas?

What type of liquid or gas?

What temperature will the vessel see?

Are you qualified to do this?

The list of questions can rapidly exceed 20.

We don't like 20 questions here.

ASME Section VIII Div 1 , vessel contains liquid at ambient conditions. I looked into code and Megyesy's book but could'nt find it. All I need is a book or reference containing the required design strategy or steps for help.

"...vessel contains liquid at ambient conditions."

Eh?

I don't know much about vessel skirts, but have seen some skirts with openings where there probably should not be one.

If there is enough space around the opening, you could use a reinforcement pad of thickness equal to skirt thickness and OD = 2 x opening D. This is conservative; actual calculation may enable you to use less.

Go back to the original equipment manufacturer [OEM] for advice. Its details are on the plate attached permanently to the vessel. They may even have the vessel's General Arrangement drawing and calculations on file once the identity of the vessel is known and presented to them.

The OEM will be up-to-date with current vessel construction codes. Not to go to them in the first intance is abstruse. Pick up the phone, and talk to them.

Consult the relevant design code.

regarding your questions, the opening calculations in the vertical pressure vessel skirts are related to two types of stresses which its very easy to calculate it as the following steps:

*as it is a pre existing vessel, you can take some deminsions for the skirt like the thickness and internal diameter amd calculate

*as this is a pre existing pressure vessel, so you can estimate the hydro-test weight of the vessel which will produce axial loads on the skirt cross section area and thickness.

*for vertical vessels, the wind/seismic loads acting on it, and will produce over turning moment on the skirt, then you should know these loads.

*after you estimate these loads as an inputs in your calculation,make to check calculation as the following:

***first check the required cross section area at the center of the opening that required by the axial load (due to weight) and also the required cross section area required by the over turning moment (due to seismic or wind) after and before opening.

*secound check the new momnet of inertia (after the opening) at the center of the skirt opening ( which shall be equal to the old moment of inertia"before opening)"

finally, you can estimate the required sleeve or pipe which will locate at the opening to equalize the old and new moment of inertia and to substitute the removed area (so the old and new area will be the same) and be adequate to stand against the stress causes by the weight and (wind /seismic) loads.

these calculation will need from you some trail and error method, but you will got it after at least 2 trails.

good luck