Full Content is available to subscribers

Subscribe/Learn More  >

Parametic Investigation on Limit Pressure of In-Service Welding Pipes

[+] Author Affiliations
Xiaolong Xue, Zhifu Sang

Nanjing University of Technology, Nanjing, China

Jiagui Zhu

Nanjing Yangzi Petrochemical Maintenance and Installation Company, Ltd., Nanjing, China

G. E. O. Widera

Marquette University, Milwaukee, WI

Paper No. PVP2006-ICPVT-11-94064, pp. 241-245; 5 pages
  • ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference
  • Volume 3: Design and Analysis
  • Vancouver, BC, Canada, July 23–27, 2006
  • Conference Sponsors: Pressure Vessels and Piping Division
  • ISBN: 0-7918-4754-3 | eISBN: 0-7918-3782-3
  • Copyright © 2006 by ASME


In-service welding is the key operation of hot tapping which allows establishing a branch connection to a live pipeline. As there is no need to halt transportation, it can avoid large economic losses and serious air pollution. However, the operation is made much more difficult than normal welding by the pressure, temperature and flowing of contents. Firstly, the local high temperature causes a loss of material strength during in-service welding. Burn-through may occur if the region with elevated temperature can not support the stress it suffered. Secondly, the flowing media create a large heat loss through the pipe-wall, resulting in accelerated cooling of the weld, which increases hardness of HAZ and possibility of HAZ cracking. In this paper, temperature distribution of in-service welding under variable parameters onto SS304 pipeline with tap water flowing in the pipes were simulated by FEM. Temperature dependent material properties and effects of convection and radiation were considered. Internal heat generation and amplitude loading were used to simulate the moving heat source. The effect of the flowing of internal media was regarded as forced convection. Based on the results of temperature field, RSF and limit pressure of the pipe can be obtained and burn-through can be predicted. It can be concluded that the limit pressure decrease with the increasing of heat input. RSF increases with the increasing of pipe-wall thickness. While the thickness increases to an extent, RSF show little increase. RSF and limit pressure of the pipe increase with the increasing of flow rate. There is a range that the increase changes greatly. While in-service welding, the range should be adequately considered to determine operating condition optimally. According to the results, the maximum of heat input and minimum of pipe-wall thickness can be obtained.

Copyright © 2006 by ASME
Topics: Pressure , Welding , Pipes



Interactive Graphics


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

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