Limit of re-pad thickness. 2

[mechengineer]

Hi experts,
Any limits from code for the thickness of re-pad? 1.5*ts or 2ts?
Thanks.

 

[r6155]

And the CODE is????

Regards

 

[MJCronin]

Code ??...... BWHAAHAHAHA !!!! .... We don't need no stinkin' Code here in this country !!!

BWHAHAHA !!! ..... We just use random bits and pieces from a vast variety of International Codes and Standards to design, fabricate inspect and test our contracted pressure vessels !!! BWHAHAHAHA !!!

We use ASME, EN, PED, BS, Chinese PV Code and many, many others !!! .... We use eng-tips as an authority as well as the vague recollections of some of our senior staff !!!

BWHAHAHAHA !!!

Oh, .....and we always do whatever the client demands even if it violates our experience and engineering common sense .... Someone at eng-tip will later tell us that it is OK !!! ....... BHAHAHAHA !

MJCronin
Sr. Process Engineer

 

[r6155]

No limits for the adopted re-pad.

Regards

 

[SnTMan]

... but no credit for any thickness laying outside the limits of reinforcement.

If the concept applies to whatever Code, if any

Regards,

Mike

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

 

[RJW000]

I’ve seen it limited to shell thickness.

What is the design temperature?

 

[Geoff13]

Assuming you're asking about Section VIII, the Code doesn't limit the reinforcing plate thickness.

However many manufacturer's would limit it per their own "good practice" rules. Something in the 1.5t range is a pretty typical limit.

Repads are usually t since you already have material that thick.

 

[mechengineer]

Excepet the <pressure Vessel Design Manual>, UG-37 of ASME VIII-1 does not give the limit for 'te' of re-pad thickeness for A5. The limits of reinforement in UG-40 are only for shell (along the shell axis) and nozzle (along the nozle axis). If client specification does not give the limit, the designer may use the thickness of re-pad up to 1.5 time of shell thickness as per <pressure Vessel Design Manual>. It requires the re-pad thickness shall be equal and less than 1.5 times of shell thickness in BG-150 (China Code). ASME code does not give the limit that means allowing the thickness of re-pad larger that 1.5 times of shell thickness.

Regards,

 

[SnTMan]

mechengineer, suggest you re-read UG-40(c) and examine Fig UG-37.1, left side

Normal to vessel wall, Lesser of 2.5t or 2.5tn+te

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

 

[Krausen]

From a practical best practice standpoint, typically limited to the thickness of shell. Costs increase with little benefit going beyond the shell thickness for repads.

 

[mechengineer]

This is the limit of nozzle height can be used for the reinforcement, not ‘te’.
Regards.

 

[SnTMan]

No, that is the limit of anything acting as reinforcement.

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

 

[pperlich]

SnTMan is correct. The definition of A5 references Note 2, which establishes the effective limit of the repad thickness.

In my business, repads have always been ≤ shell/head thickness.

Phil

http://www.quicktanks.com

 

[r6155]

You can use a pad thickness higher than the credit limit on UG-37
But be careful, you may fall into a PWHT requirement.

Regards

 

[XL83NL]

MJC you made me laugh and so made my day! A star for your post.

Huub
- You never get what you expect, you only get what you inspect.

 

[SnTMan]

Ordinary practice in my experience, limited to 1 to 1 1/2 X shell thickness. Some client specs place limits as I recall.

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