×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Shell and Head Replacement - Design Calculations?

Shell and Head Replacement - Design Calculations?

Shell and Head Replacement - Design Calculations?

(OP)
When a head and attached shell section of a Section VIII vessel is being replaced it would seem that new design calculations would not be necessary assuming the replacement is like-for-like to the original in all details, e.g., material, thickness, and location of nozzles. State is Illinois

Opinions please?

RE: Shell and Head Replacement - Design Calculations?

Just some thoughts.
I would verify if this repair is required to be done according to original code of construction or current code.
If current code is use, design formulas may have changed from the original construction and that would require re-calculations.
In general, codes have evolved allowing for thinner material.I would not take that for granted but if that is the case it could give lower minimum wall thickness thus far increasing corrosion allowance and lifespan of the vessels.  

RE: Shell and Head Replacement - Design Calculations?

If all variables are same (operating conditions, fluids, flowrates), and materials of replacement vessel and quality of workmanship are same, there should be no difference in life expectancy from a vessel built in 1950 or 2011.

Just because the theoretical formulas for thickness requirements and corrosion allowances have changed, the actual properties of fluids, and the phyiscal relationships between materials have not.

-TJ Orlowski

RE: Shell and Head Replacement - Design Calculations?

If the original design and applicable code year are not changed then no new calculation is required. This is called 'repair' or 'replacement in-kind'.

RE: Shell and Head Replacement - Design Calculations?

NBIC repair but you mention location of nozzles?   rthat is an alteration
so pls consult your AI...

 

RE: Shell and Head Replacement - Design Calculations?

NBIC repair but you mention location of nozzles?   that is an alteration
so pls consult your AI...

 

RE: Shell and Head Replacement - Design Calculations?

Is the welding procedure equal to original construction?

Is the Original fabricator do the replacement?

Regards

r6155

RE: Shell and Head Replacement - Design Calculations?

I get it, if you use the same materials the design is the same, if other materials then it has to be recalculated and it would be better to the same Edition and Add. if available.

 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources