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

Ambient and design temperature

Ambient and design temperature

(OP)
Dear Friends,

I'm new in stress analysis and I'm doing stress analysis on a pipeline connected to a pig trap; about 25 meters of pipeline is above ground and existing part is underground. According to the site condition document "Average minimum absolute ambient temperature" of the field is 1°C, "Average maximum absolute ambient temperature" is 48°C and minimum soil temperature is 16°C in winter. It should be mentioned that maximum operating temperature is 31°C.
I have some doubts about temperatures:
1- Which of above temperature should be considered as ambient temperature in "special execution option" of CAESAR II?
2- Should I consider sunshine temperature(85°C) for above ground portion and maximum operating temperature(31°C) for UG portion of the pipeline for stress, displacement and load calculations?


I have another question:
How can I model a pig trap? Is it true to consider an anchor point at interference of pipeline and pig trap? If yes, the nozzle load is really huge. If not, how can I deal with the trap?

Sincerely,

RE: Ambient and design temperature

Averages are of no use.
Design temperatures should include the max and min of all possible temperature excursions.
Design pressures should include the max and min of all possible pressure excursions.

i.e. Use 85C for max above ground pipe. Minimum for above ground piping should be minimum air temperature.

Operating temperatures, when within the max-min range above, are not relevant. If outside the above range, move the relevant design temperature to include it.

Although B31.4 designs can have surge pressures up to 10% higher than design pressure. Be extension, design pressure should at least equal MAOP at the design temperature.

RE: Ambient and design temperature

Model the pig launcher from the point on the underground pipeline that locates the "virtual soil anchor", the point where the soil restrains the pipe. It requires some knowledge of soil properties.

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