Skip to content
BY-NC-ND 4.0 license Open Access Published by De Gruyter Open Access December 4, 2021

Numerical evaluation of expansion loops for pipe subjected to thermal displacements

  • Hartono Yudo EMAIL logo , Sarjito Jokosisworo , Wilma Amiruddin , Pujianto Pujianto , Tuswan Tuswan and Mohamad Djaeni


The thermal expansion can lead to the high stress on the pipe. The problem can be overcome using expansion loops in a certain length depending on the material’s elastic modulus, diameter, the amount of expansion, and the pipe’s allowable stresses. Currently, there is no exact definition for the dimension of expansion loops design both for loop width (W) and loop footing height (H) sizes. In this study, expansion loops were investigated with using ratio of width and height (W/H) variations to understand pipe stress occurring on the expansion loops and the expansion loops’ safety factor. Relationship between non dimensional stress on the expansion loop pipe was studied numerically by finite element software on several working temperatures of 400oF, 500oF, 600oF, and 700oF. It can be found that stress occurring on the pipes increases as the increases of W/H of the expansion loops and results in a lower safety factor. The safety factor of the expansion loops pipe has a value of 1 when the ratio of loop width and loop footing height (W/H) value was 1.2 for a 16-inch diameter pipe. Stress occurring on the pipe increases with the increase of the working temperature. Expansion loops pipe designed for 400oF can still work well to handle thermal extension pipe occurring on 500oF.


[1] American Society of Mechanical Engineers. ASME B31.3 Process Piping-ASME Code for Pressure Piping. New York: American Society of Mechanical Engineers. 2014.Search in Google Scholar

[2] Kannappan S. Introduction to Pipe Stress Analysis. Canada: John Wiley & Sons, inc. 1986.Search in Google Scholar

[3] Huang J, Xiang J, Chu X, Sun W, Liu R, Ling W, et al. Thermal performance of flexible branch heat pipe. Appl Therm Eng. 2021;186:16532.10.1016/j.applthermaleng.2020.116532Search in Google Scholar

[4] Lukassen TV, Gunnarsson E, Krenk S, Glejbøl K, Lyckegaard A, Berggreen C. Tension-bending analysis of flexible pipe by a repeated unit cell finite element model. Mar Struct. 2019;64:401-20.10.1016/j.marstruc.2018.09.010Search in Google Scholar

[5] Tang T, He W, Zhu X. Parameter sensitivity analysis on the buckling failure modes of tensile armor layers of flexible pipe. Eng Fail Anal. 2019;104:784-95.10.1016/j.engfailanal.2019.06.078Search in Google Scholar

[6] Yoo DH, Jang BS, Yim KH. Nonlinear finite element analysis of failure modes and ultimate strength of flexible pipes. Mar Struct. 2017;54:50–72.10.1016/j.marstruc.2017.03.007Search in Google Scholar

[7] Hastie JC, Kashtalyan M, Guz IA. Failure analysis of thermoplastic composite pipe (TCP) under combined pressure, tension and thermal gradient for an offshore riser application. Int J Press Vessel Pip. 2019;178:103998.10.1016/j.ijpvp.2019.103998Search in Google Scholar

[8] American Society of Mechanical Engineers. ASME B31.1 Power Piping-ASME Code for Pressure Piping. New York: American Society of Mechanical Engineers. 2014.Search in Google Scholar

[9] Jaćimović N. Uncertanties in expansion stress evaluation criteria in piping codes. Int J Press Vessel Pip. 2019;169:230-41.10.1016/j.ijpvp.2019.01.003Search in Google Scholar

[10] Wiley J. Design of Piping System, 2nd ed. United States of America: The M. W. Kellog Company. 1956.Search in Google Scholar

[11] Alhussainy F, Sheikh MN, Hadi MNS. Behaviour of Small Diameter Steel Tubes Under Axial Compression. Structures. 2017;11:155-63.10.1016/j.istruc.2017.05.006Search in Google Scholar

[12] Yudo H, Yoshikawa T. Buckling phenomenon for imperfect pipe under pure bending. J Mar Sci Technol. 2015;29(6):703-10.10.1007/s00773-015-0324-3Search in Google Scholar

[13] Yudo H, Amiruddin W, Jokosisworo S. Analysis of the buckling moment on rectangular hollow pipe under pure bending load. MATEC Web Conf. 2018;177(11):228-35.10.1051/matecconf/201817701012Search in Google Scholar

[14] Xie P, Zhao Y, Yue Q, Palmer AC. Dynamic loading history and collapse analysis of the pipe during deepwater S-lay operation. Mar Struct. 2015;40:183-92.10.1016/j.marstruc.2014.11.003Search in Google Scholar

[15] Shehadeh B, Ranganathan SI, Abed FH. Optimization of Piping Expansion Loops Using ASME B31.3. Proc. Inst. Mech. Eng. Part E J Process Mech Eng. 2016;230(1):56-64.10.1177/0954408914532808Search in Google Scholar

[16] Rao RN, Maiya M, Prabhu S, Santhosh G, Hebbar G. The analysis of a piping system for improvement of a system in a process unit. Mater Today Proc. 2021;46(7): 2791-7.10.1016/j.matpr.2021.02.595Search in Google Scholar

[17] Verma AK, Yadav BK, Gandhi A, Saraswat A, Verma S, Kumar ER. 3D modelling of loop layout, pipe stress analysis and structural responses of high-pressure high-temperature experimental helium cooling loop (EHCL). Fusion Eng Des. 2019;145:87–93.10.1016/j.fusengdes.2019.05.015Search in Google Scholar

[18] Yudo H, Yoshikawa T. Buckling Phenomenon for Straight and Curved pipe Under Pure Bending. J Mar Sci Technol. 2015;20(1):94–103.10.1007/s00773-014-0254-5Search in Google Scholar

[19] Kang SJ, Choi JH, Lee H, Cho DH, Choi, JB, Kim MK. Limit load solutions for elbows with circumferential through-wall crack under the pressure-induced bending restraint effect. Int J Press Vessel Pip. 2019;177:103983.10.1016/j.ijpvp.2019.103983Search in Google Scholar

[20] Sorour SS, Shazly M, Megahed MM. Limit load analysis of thin-walled as-fabricated pipe bends with low ovality under in-plane moment loading and internal pressure. Thin-Walled Struct. 2019;144:106336.10.1016/j.tws.2019.106336Search in Google Scholar

[21] ASTM A106 / A106M-19a, Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service, ASTM International, West Conshohocken, PA, 2019,Search in Google Scholar

[22] Abdalla HF. Load carrying capacities of pressurized 90 degree miter and smooth bends subjected to monotonic in-plane and out-of-plane bending loadings. Int J Press Vessel Pip. 2019;171:253-70.10.1016/j.ijpvp.2019.03.002Search in Google Scholar

[23] Balakrishnan S. Veerappan AR. Shanmugam S. Determination of plastic, shakedown and elastic limit loads of 90° pressurized pipe bends with shape imperfections. Int J Press Vessel Pip. 2019;175:103925.10.1016/j.ijpvp.2019.103925Search in Google Scholar

[24] Yu W, Liu Z, Fan M, Gao H, Liu E, Chen M, et al. The effect of constraint on fracture properties of Z3CN20.09M after accelerated thermal aging. Int J Press Vessel Pip. 2021;190:104294.10.1016/j.ijpvp.2020.104294Search in Google Scholar

Received: 2021-06-27
Accepted: 2021-10-08
Published Online: 2021-12-04

© 2022 Hartono Yudo et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Downloaded on 6.6.2023 from
Scroll to top button