Contact US

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.

Students Click Here

Relief Line Thrust Force Dissipation?

Relief Line Thrust Force Dissipation?

Relief Line Thrust Force Dissipation?


My company is currently stress analysing a series of 36" vent/releif lines. The main relief line has a 36" rupture disc and also a 10" connecting branch line with a PRV. The design pressure for the line is 150 psig. Doing a simple thrust force calculation of F=P*A results in a very high force which is creating lots of issues for the structural group in restraining the pipe.

Since the vent on the releif line is significantly far away from both the PRV and the rupture disc, it is assumed that the pressure from the popping of either item will dissipate prior to reaching the vent and not exit the system at the design pressure. Is there a way to calculate the pressure loss through the system?


RE: Relief Line Thrust Force Dissipation?

Yes there are methods to calculate the pressure loss through the system and this should have been done by your Process group to ensure the backpressure at the bursting disc and the RV are acceptable and this is how they should have determined that the pipe size is acceptable.

RE: Relief Line Thrust Force Dissipation?

Good day,

I'm trying to model the thrust force due to a relief valve. I was wondering if when I run the analysis in CAESAR, should I remove the pressure load in the operating case? Or should I determine the pressure gradient away from the relief valve first.

I have a 42" PIG Launcher system operating at 120F and 1440psig and am looking for the effect of the relief valve, which faces straight up, on the pipe support pedestal. The pipeline is using natural gas and I have already figured a maximum thrust force of around 250kips.

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! Already a Member? Login


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