Conical Head in Chemical and General Industries

[takiyasamsama]

Hi,

Is there any rules for design of conical head for vessel in chemical and general industries? The reason is if following ASME Section VIII Div.1, the angle should be 30 degrees or less, however in this one chemical plant I'm currently doing, their cone angle more than 30 degrees (about 70 to 80 degrees).

Can anyone advice me on this one?

 

[gr2vessels]

Please first clarify, if the equipment is pressure vessel, vertical storage tank or silo on legs or skirt, what is it? Conical roof on storage tank is typically 9.5 deg (aka 71 deg cone top). Which code you are working with?
Cheers,
gr2vessels

 

[takiyasamsama]

The said equipment is considered a reactor by client. The vessel itself was fabricated and operating in another plant and this one is a copy of that one. However when asked client regarding the code of standard, client wasn't sure which code they're using.

It's basically a vertical vessel with cooling halfpipe jacket, a mixer, and a heating coil inside supported by a support lugs. As I was looking through ASME in Appendix 1-5(g) it mentioned that if the vessel's cone is constructed more than 30 degrees than it shall be analyse using special analysis (or FEA).

So that is why I wanted to know is there any codes and standard when fabricating a vessel for chemical plant or other than ASME. Specifically for the rules of construction for conical head.

 

[prex]

EN13445, as an example, gives explicit rules for cones with a half apex angle not greater than 75 degrees.
However, as you cannot likely choose your code, you should first determine which one applies.

prex
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[gr2vessels]

Where is the conje, bottom or roof? Where is the nameplate of the equipment, can you take a picture? It might be a simple API 620 tank with conical bottom, with halfpipe jacket. From your post I understand the 70-80 deg angle refers to roof cone, not bottom cone. Can you please describe your equipment in full, not half sentences? Do you have some details like wall thickness, is it operating under pressure? Is it a vertical mixer installed on roof or is a side stab-in mixer? Can you please try to be a bit more coherent in describing the equipment?
Cheers,
gr2vessels

 

[takiyasamsama]

Maybe this image can help you guys understand what I'm facing right now.

 

[prex]

You have toriconical heads (conical heads with a knuckle), so the limit of 30 deg does not apply. You can calculate the head and knuckle thicknesses according to UG-32(h)

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