Research Papers: Materials and Fabrication

Mathematical Approaching and Experimental Assembly to Evaluate the Risks of In-Service Welding in Hot Tapping

[+] Author and Article Information
Ivo Andrei de O. L Lima

Braskem S.A.,
Camaçari 42810-000, Bahia, Brazil
e-mail: ivo.lima@braskem.com

Alex Alisson Bandeira Santos

SENAI CIMATEC—Integrated Center of
Manufacturing and Technology,
Salvador 41650-010, Bahia, Brazil
e-mail: alex.santos@fieb.org.br

Contributed by the Pressure Vessel and Piping Division of ASME for publication in the JOURNAL OF PRESSURE VESSEL TECHNOLOGY. Manuscript received December 27, 2014; final manuscript received August 28, 2015; published online October 8, 2015. Assoc. Editor: Xian-Kui Zhu.

J. Pressure Vessel Technol 138(2), 021403 (Oct 08, 2015) (11 pages) Paper No: PVT-14-1213; doi: 10.1115/1.4031506 History: Received December 27, 2014; Revised August 28, 2015

The welding onto in-service pipeline (operation condition) results in three possibilities of high risks: leaking and/or explosion by burn-through, chemical reactions to instability, or even explosion due to the heat on internal fluid and cracking in heat affected zone (HAZ). The numerical methods have a useful role in the assessment of welding conditions for the safe in-service welding of pipelines. Only limited published works have considered direct calculation of burn-through using a combination of thermal and stress analysis. The mathematical model of the heat source is the most important part of these numerical models, and actually the mathematical model which described better the heat distribution of the arc welding through gas-shielded tungsten arc welding (GTAW) process or shielded metal arc welding process is the double ellipsoidal heat source (DEHS) model of Goldak and Akhlaghi (2010, Computational Welding Mechanics, Springer Books, New York, pp. 32–35). However, that model has considered the heat source in rectilinear motion only, and it depends on three parameters (a, b, c) which are related with the weld bead size and shape to define the geometry and co-ordinates of heat source, and they are determined empirically or experimentally. Few researchers published works that could determine these parameters mathematically, from the welding data. The publication that best analytically addressed this issue was the work of Eagar and Tsai (1983, “Temperature Fields Produced by Traveling Distributed Heat Sources,” Weld. J., 62(12), pp. 346–355). First, this paper presents a new equation for heat source in double ellipsoid considering the circular motion, trying to develop a model closer to the physical situation of hot tapping onto pipeline. Second, a proposal for determination of the parameters a, b analytically from the Eagar model and Tsai (1983, “Temperature Fields Produced by Traveling Distributed Heat Sources,” Weld. J., 62(12), pp. 346–355), and third, an experimental facility to get the temperature field that was used to validate the numerical finite element models.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.


Sabapathy, P. N. , Wahab, M. A. , and Painter, M. J. , 2005, “ The Onset of Pipewall Failure During ‘In-Service’ Welding of Gas Pipelines,” J. Mater. Process. Technol., 168(3), pp. 414–422. [CrossRef]
American Petroleum Institute, 2004, “ Welding Inspection and Metallurgy,” Report No. API 577, Washington, DC.
American Petroleum Institute, 2003, “ Procedures for Welding or Hot Tapping on Equipment Containing,” Report No. API 2201, Washington, DC, p. 12.
Tahami, V.-F. , and Asl, M.-H. , 2009, “ A Two-Dimensional Thermomechanical Analysis of Burn-Through at In-Service Welding of Pressurized Canals,” J. Appl. Sci., 9(4), pp. 615–626. [CrossRef]
Goldak, J. A. , Oddy, A. S. , and Dorling, D. V. , 1993, “ Finite Element Analysis of Welding on Fluid Filled,” Pressurised Pipelines, ASM International, Gatlinburg, TN, pp. 45–50.
Sabapathy, P. N. , Wahab, M. A. , and Painter, M. J. , 2001, “ Numerical Models of In-Service Welding of Gas Pipelines,” J. Mater. Process. Technol., 118(1–3), pp. 14–21. [CrossRef]
Goldak, J. A. , and Akhlaghi, M. , 2010, Computational Welding Mechanics, Springer Books, New York, pp. 32–35.
Chriestensen, N. , Davies, V. , and Gjermundsen, K. , 1965, “ The Distribution of Temperature in Arc Welding,” Br. Weld. J., 12(2), pp. 54–75.
Rosenthal, D. , 1946, “ The Theory of Moving Sources of Heat and Its Application to Metal Treatments,” Trans ASME, 68, pp. 849–865.
Eagar, T. W. , and Tsai, N. S. , 1983, “ Temperature Fields Produced by Traveling Distributed Heat Sources,” Weld. J., 62(12), pp. 346–355.
Friedman, E. , 1975, “ Thermo-Mechanical Analysis of the Welding Process Using the Finite Element Method,” ASME J. Pressure Vessel Technol., 97(3), pp. 206–213. [CrossRef]
Krutz, G. W. , and Sergerlind, L. J. , 1978, “ Finite Element Analysis of Welded Structures,” Weld. J. Res. Suppl., 57, pp. 211s–216s.
American Society of Mechanical Engineers, 2004, Boiler & Pressure Vessel Code, Section II Part D, Subpart 1 and 2, ASME, New York, pp. 498–703.
American Society of Mechanical Engineers, 2010, Code for Pressure Piping, Process Piping ASME B31.3, Appendix C, ASME, New York, pp. 209–225.
Deng, D. , and Murokawa, H. , 2008, “ Finite Element Analysis of Temperature Field, Microstructure and Residual Stress in Multi-Pass Butt-Welded 2.25Cr–1Mo Steel Pipes,” Comput. Mater. Sci., 43(4), pp. 681–695. [CrossRef]
ANSYS, 2012, User’s Manual, Mechanical APDL Release 14.5, ANSYS, Canonsburg, PA.
Yaghi, A. , Hyde, T. H. , Becker, A. A. , Sun, W. , and Williams, J. A. , 2006, “ Residual Stress Simulation in Thin and Thick-Walled Stainless Steel Pipe Weld Including Pipe Diameter Effects,” Int. J. Pressure Vessels Piping, 83, pp. 864–874. [CrossRef]
Smartt, H. , Einerson, C. J. , and Stewart, J. A. , 1985, AWS Annual Meeting, Las Vegas, NV.
Bang, I . W. , Son, Y. P. , Oh, K. H. , Kim, Y. P. , and Kim, W. S. , 2002, “ Numerical Simulation of Sleeve Repair Welding of In-Service Gas Pipelines,” Weld. J., 81(12), pp. 273-S–282-S.
Lindgren, L.-E. , 2006, “ Numerical Modeling of Welding,” Comp. Methods Appl. Mech. Eng., 195, pp. 6710–6736. [CrossRef]
Vakili-Tahami, F. , Zehsaz, M. , and Saeimi-Sadigh, M. , 2010, “ Finite Element Analysis of the In-Service Welding of T Joint Pipe Connections,” Eur. J. Sci. Res. 40(4), pp. 557–568.


Grahic Jump Location
Fig. 1

Model of double ellipsoid of Goldak and Akhlaghi [7]

Grahic Jump Location
Fig. 2

Gaussian heat source

Grahic Jump Location
Fig. 3

Cylindrical coordinates for pipe model

Grahic Jump Location
Fig. 4

Coordinate system used for DEHS in rectilinear movement (a) and circular movement (b)

Grahic Jump Location
Fig. 5

Experimental models 1 and 2 and your numerical models, respectively

Grahic Jump Location
Fig. 6

(a) Plant view and cross section of the model 1, (1) metal base and (2) vertical plate. (b) Plant view and cross section of the model 2.

Grahic Jump Location
Fig. 7

Experimental and numerical values for the thermocouples TP-3 up to TP-8 during the first and second pass—Model 1

Grahic Jump Location
Fig. 8

Experimental and numerical values for the thermocouples TP-7 and TP-8 during the first pass—Model 2

Grahic Jump Location
Fig. 9

Width (a) and depth (b) for T joint

Grahic Jump Location
Fig. 10

Equivalence between surface areas

Grahic Jump Location
Fig. 11

Finite elements mesh of the tubular model

Grahic Jump Location
Fig. 12

Boundary conditions

Grahic Jump Location
Fig. 13

General view and main components

Grahic Jump Location
Fig. 14

The proposed numerical model can predict the burn-trough risk with 120 A. The numerical model showed the equivalent stress above the yield stress at 80% of the cross section.

Grahic Jump Location
Fig. 15

The proposed numerical model can be predicted which there will not burn-through with 80 A. The numerical model showed the equivalent stress above the yield stress at less than 5% of the cross section.




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 Journal Articles
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