×
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

Bent in shell of pressure vessel (residual stresses)

Bent in shell of pressure vessel (residual stresses)

Bent in shell of pressure vessel (residual stresses)

(OP)
I have a pressure vessel with bent in its shell. So I want to evaluate this vessel acc. ASME BPVC VIII div.2 Part 5 in elastic-plastic method.
My way-
1) I build a geometry model of the vessel with the bent.
2) Use the appropriate procedure describing in ASME

Here I have a question-
When the bent was created, it have become to have residual stresses, which I haven`t taken into account. So my evaluation of vessel is wrong?
So, to evaluate this vessel right-
1)I have to model the vessel WITHOUT the bent, then to model the creation of bent (e.g. by indentor). So I get residual stresses and then
2) Use the appropriate procedure describing in ASME

Am I right?
Thanks for advance!

RE: Bent in shell of pressure vessel (residual stresses)

The latter option may be more technically defensible. However, I have done that type of analysis both ways. If you have the time and inclination, I would suggest that you do both, compare the results, and then publish that comparison at PVP2016.

RE: Bent in shell of pressure vessel (residual stresses)

beastgod......

How big is the defect ???

Can you give us pictures ?

MJCronin
Sr. Process Engineer

RE: Bent in shell of pressure vessel (residual stresses)

(OP)
to TGS4-
OK, thanks for invitation, I will try to compare.

to MJCronin-
Here pictures:
sizes of bents
http://files.engineering.com/getfile.aspx?folder=d....
a general form
http://files.engineering.com/getfile.aspx?folder=c...
angle distribution map (degrees)
http://files.engineering.com/getfile.aspx?folder=c...

Diameter is 2400 mm and thickness is 3 mm. Pressure is 0.3 MPa.

How can you predict whether we should model residual stresses or not? By experience?
Thank you

RE: Bent in shell of pressure vessel (residual stresses)

I would recommend you use API 579-1/ASME FFS-1 "Fitness-for-Service". There is a special chapter for shell distortion, bulges and dents.

Daniel Breyer
Inspection Engineer

http://lnkd.in/dFcQA-w

RE: Bent in shell of pressure vessel (residual stresses)

The "picture" is more a "map" or location for the problem spots.

What do the bends and dents look like? The actual shape of the edges of the bent steel are the stress risers, and the physical shape of each indent is (I am assuming the dents go "into" the tank!) very important. Some curves may be shallow and not very important even though they are larger, another very important if the shape creates a sharper kink.

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