0

Full Content is available to subscribers

Subscribe/Learn More  >

Mitigation of Bending Stress and Failure Due to Temperature Differentials in Piping Systems Carrying Multiphase Fluids: Using CFD and FEA

[+] Author Affiliations
Philip Diwakar, Vibhor Mehrotra, Franklin Richardson

Bechtel Corporation

Paper No. IMECE2005-79969, pp. 85-93; 9 pages
doi:10.1115/IMECE2005-79969
From:
  • ASME 2005 International Mechanical Engineering Congress and Exposition
  • Recent Advances in Solids and Structures
  • Orlando, Florida, USA, November 5 – 11, 2005
  • Conference Sponsors: Pressure Vessels and Piping Division
  • ISBN: 0-7918-4228-2 | eISBN: 0-7918-3769-6
  • Copyright © 2005 by ASME

abstract

The bending of large pipes due to temperature differentials between the bottom and top of the pipe is a very serious problem. The temperature differentials can either be caused by extremely cold liquids (such as methane or ethylene flowing from a lateral into a flare header) or hot liquids flowing at the bottom of a piping system (such as in a Vacuum transfer line) while the top is exposed to atmospheric conditions. In some cases liquids may be produced by Joule-Thompson cooling of high pressure cold gas as it expands through a safety-relief or emergency depressurization valve. The liquid so formed can accumulate, for example, on the dead leg side of a flare header. The differential expansion can deform the pipe so that it lifts off its supports. It takes a finite amount of time for the heat transfer by conduction to equilibrate the temperature to a more benign level. The initial stresses induced due to large thermal differential may even cause the pipe to crack in the region of the supports and T-joints to the laterals. This phenomenon has been observed in several industries, most predominantly in the petrochemical industry. This paper recounts the use of Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) to study this important phenomenon. The liquid flowing from the lateral into the main header pipe is multiphase in the dispersed, stratified, slug or annular flow régime. Multiphase flows with heat transfer are analyzed using CFD. The temperatures on the walls of the pipe system are then transferred to the FEA and analyzed for heat transfer and thermal stresses. These stresses are compared to ASME standards to see if they are within allowable limits. This paper also recounts efforts to reduce the bending effect by preventing liquid accumulation on the dead leg side. Other methods that provide better supports for bent piping are studied. Further, methods of equilibrating the temperature faster to prevent the bowing of the pipe are also studied. It is hoped that this presentation will benefit people designing piping networks with varying liquid and vapor traffic by providing a safe environment free of cracks and spills.

Copyright © 2005 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In