Steel pipe under high external pressure

Click For Summary

Discussion Overview

The discussion revolves around the safety of a steel pipe subjected to high external pressure due to submersion. Participants explore calculations related to yield limits, external pressures, and structural integrity, with a focus on theoretical and practical implications for a research project.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • Per-Tore Aasestrand presents a scenario involving a steel tube with specific dimensions and yield limits, questioning its safety under external pressure of 69 MPa.
  • One participant suggests using the ASME piping code for determining safe stresses on externally pressurized pipes, referencing a previous discussion for further context.
  • Another participant notes the potential availability of equivalent European codes for structural analysis, emphasizing legal compliance for industrial applications.
  • Per-Tore clarifies that the project is for research and does not require code compliance, seeking information on the pipe's ability to withstand the external pressure and the associated safety margins.
  • A separate inquiry about locating a specific casing pipe is introduced, indicating a need for practical sourcing of materials.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the safety of the pipe under the specified conditions, and multiple approaches to assessing the situation are presented without resolution.

Contextual Notes

Participants express varying levels of familiarity with relevant codes and methodologies, and there is an acknowledgment of the need for specific calculations that may depend on additional assumptions or definitions not fully explored in the discussion.

Who May Find This Useful

This discussion may be of interest to engineers, researchers, and students involved in structural analysis, materials science, and applied physics, particularly those focusing on pressure vessel design and safety assessments.

ptaa32
Messages
2
Reaction score
0
Hi,

We have a steel tube with yield limit 1000 N/mm2.
It is 250 mm long, outside diam. is 76 mm, inside diam. is 60 mm.
It is plugged at both ends.
Inside pressure is 0 (zero) and outside pressure due to submersion is 69 Mpa.

Will this be safe?
How can I calculate what pressure that would be 'catastrophic' for the pipe?

Kind regards,

Per-Tore Aasestrand
Bergen, Norway
 
Last edited:
Engineering news on Phys.org
Hi Per-Tore, welcome to the board. I would use the ASME piping code to determine safe stresses on externally pressurized pipe. We had a discussion on this here:
https://www.physicsforums.com/showthread.php?t=532901
If you don't have access to the ASME BPV code, you might consider using Roark's but I always use the ASME code for this and am not familiar with how Roark's does this and I've left my copy at the office.

Edit: I'm sure there's a piping code in Europe which is equivalent to the ASME code in the US. If this is an industrial application, you will be required by law to perform the structural analysis per the applicable European code.
 
Last edited:
Hi,

Thanks for the tip.
It is for a research project, so there is no need for code compliance.
The cylinder will contain some instrumentation, and I only need to know if it will survive the depth. Preferably also what the margins are.
 
Casing Pipe 139.7*9.17 , mark C-75

Who can find this casing pipe ?
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
5K
  • · Replies 7 ·
Replies
7
Views
8K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 12 ·
Replies
12
Views
35K
  • · Replies 3 ·
Replies
3
Views
18K
Replies
6
Views
2K
  • · Replies 11 ·
Replies
11
Views
6K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
1
Views
5K