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!

*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.

Jobs

API 650 paragraph 5.7.4.3.

API 650 paragraph 5.7.4.3.

(OP)
Dear experts,

Many times this issue come from the clients.

5.7.4.3 When the shell material is Group IV, IVA, V, or VI, all opening connections requiring reinforcement in a shell
plate or thickened insert plate more than 13 mm (1/2 in.) thick shall be prefabricated into the shell plate or thickened
insert plate, and the prefabricated assembly shall be thermally stress relieved within a temperature range of 600 °C to
650 °C (1100 °F to 1200 °F) for 1 hour per 25 mm (1 in.) of thickness prior to installation


In my understanding the statement "more than 13 mm thick" is applicable for shell plate and thickened insert plate.

But many people have different interpretation i.e. "more than 13 mm thick" is applicable for thickened insert plate only. So, by this interpretation shell plate under group IV with 10 mm thick and 10" shell nozzles and RF pad need to be prefabricated and stress relieved before installation. In other words thickness of the shell plate is not considered for stress relief. As long as there is a nozzles with RF pad stress relief must be done.

Is there any further explanation in API 650 about the above case ? I mean confirmation that 13 mm is applicable for shell plate also thickened insert plate. I found similar info on API 650 technical query but this is for group I, II, III and IIIA. I understand the explanation shall be the same for group IV, V and VI. But I would like to have your info if there is API 650 statement for group IV, V and VI.

Syah






RE: API 650 paragraph 5.7.4.3.

I'm not sure I understand the question, exactly.
Normally, if you have a reinforcing plate on the outside of the shell, it will be the same thickness as the shell. The thickness limitation there is the shell thickness, not the sum of the shell and the reinforcing plate thickness.

If, instead, you use an insert-type reinforcement that is thicker than the shell, then you may run into the 13mm limitation even with 10mm shell. In that case, the simplest solution would be switch to standard reinforcing plates instead of using insert plates.

RE: API 650 paragraph 5.7.4.3.

(OP)
JStephen,

Thanks for your response.

I will simplify the question. The statement "more than 13 mm thick" is applicable for "thickened insert plate" only or also applicable for shell plate.

If that statement is only applicable for thickened insert plate" than 10" shell nozzle with RF pad on 10 mm shell plate group IV need to be pre-fabricated and stress relieved.

To me that statement is applicable for shell plate and thickened insert plate.

Syah

RE: API 650 paragraph 5.7.4.3.

The text is meant to be read literally, and is quite clear:

"...in a shell plate or thickened insert plate more than 13 mm (1/2 in.) thick..."

The thickness limits refers to a single thickness of shell plate or thickened insert plate. It does not apply to a combination of plates such as a shell plate plus a reinforcing plate.

Regarding API groups I, II or III, the previous paragraph is also quite clear:

"...in a shell plate or thickened insert plate more than 25 mm (1 in.) thick..."

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


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close