Vessel and Tank deformation for pipe stress analysis

[ingdaniel]

Hi all,

I am doing some pipe stress analysis and I wanna considerer the deformation in the anchor point under the thermal load.

There is any way to estimate thermal deformation in the nozzle for steel storage tanks and vessel?

Thanks in advance

 

[LittleInch]

Storage tanks and vessel designers will specify maximum nozzle capacities (often very low especially for tanks). If you exceed those you can easily buckle the nozzle resulting in tank or vessel failure. Piping stress analysis normally works within given limits not to work out how the nozzle deforms which is a different tool and set of equations / simulations. Normally allowable deflections of nozzles is very low to the point of nearly zero.

It's a bit of a vague question so a bit of a vague answer. If you have a more specific question then add more details.

PS - Use of proper English is encouraged on this site and there is no real excuse for "wanna" instead of "want to" or "would like to". You're in a technical forum, not chatting with your friends on social media....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[LittleInch]

BTW in most stress analysis an anchor is exactly that and is considered not to be able to deform under any load otherwise it wouldn't be an "anchor". What I gather you meant by the second line was that you have a nozzle which is acting a bit like an anchor up to certain loads. Correct?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[ingdaniel]

No...

If the pipe is connected to the top of the tank, that will be the anchor point, but under thermal conditions the tank will expland and flange will move.

This movement is what I am asking for...

 

[BigInch]

Vertical Displacement = Average tank temperature X linear thermal expansion coefficient X distance from tank base to nozzle location.
Horizontal Displacement = Tank temperature at nozzle height X linear thermal expansion coefficient X Radius to face of nozzle.

you must get smarter than the software you're using.

 

[C2it]

In addition to thermal loads, a tank nozzle will be subjected to:

1. Rotation due to bulge, worst in the lower courses.
2. The effects of settlement and ground compression under filling / emptying.

These may be quite significant problem areas dependent upon the tank size.

Also, defining a tank nozzle as an anchor ... i.e., rotationally fixed would be very conservative, since there will actually be significant flexibility. This can be addressed using data from API 650.

IMHO, the best solution to most large tank connections at a low elevation is a double-tied bellows at the nozzle.