Thermal and Mechanical Properties of Polyethylene Pipes
Publication: Journal of Materials in Civil Engineering
Volume 19, Issue 12
Abstract
Two types of polyethylene are used for pipeline systems: medium density polyethylene and high density polyethylene. A polyethylene pipe, being a thermoplastic, softens on heating and hardens on cooling. Because of the viscoelastic nature of polyethylene, stresses decrease under applied constant strain and strains increase under applied constant stress. To account for the complex behavior of polyethylene pipe, laboratory tests were performed to study its thermal and mechanical properties. This paper presents the test results, findings, and design recommendations for polyethylene pipe properties. The tests were performed in a temperature controlled room, where properties were investigated for thermal variations expected in the field. Two types of tests were performed: stress relaxation tests and temperature ramp tests. Test methods and properties are summarized for relaxation modulus, instantaneous modulus, Poisson’s ratio, thermal expansion/contraction coefficient, and stress relaxation rates.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The funding for this study was provided by the Gas Research Institute, Brooklyn Union Gas Company, and Consolidated Edison of New York. The assistance and support provided by them is greatly appreciated. The special thanks are also extended to Thomas Michael-Jason Keeney, Tim Bond, and Ali Avcisoy for their help with the testing and preparation of the figures.
References
American Gas Association. (1994). Plastic pipe manual for gas service, Arlington, Va.
ASME. (1995). “Appendix VII. Nonmandatory procedures for the design of restrained underground piping.” ASME B31.1 code for pressure piping, New York.
ASTM. (2003a). “Standard specification for polyethylene plastics molding and extrusion materials.” 2003 annual book of standards, D4976-02, Vol. 08.03, West Conshohocken, Pa., 305–311.
ASTM. (2003b). “Standard test methods for tensile, compressive, and flexural creep and creep-rupture of plastics.” 2003 annual book of standards, D2990-01, Vol. 08.02, West Conshohocken, Pa., 203–222.
ASTM. (2003c). “Standard test method for tensile properties of plastics.” 2003 annual book of standards, D638-02a, Vol. 08.01, West Conshohocken, Pa., 46–59.
Bilgin, Ö. (1999). “Improved design and construction practices for thermal loads in plastic gas pipelines.” Ph.D. dissertation, Cornell Univ., Ithaca, N.Y.
Bilgin, Ö., and Stewart, H. E. (2001). “Designing plastic pipelines for thermal loads.” Proc., ASCE Pipelines 2001—Advances in Pipeline Engineering & Construction Conf. (CD-ROM), Sec. 30, Chap. 1, San Diego.
Catsiff, E., and Tobolsky, A. V. (1955). “Stress-relaxation of polyisobutylene in the transition region.” J. Colloid Sci., 10(4), 375–392.
Catsiff, E., and Tobolsky, A. V. (1956). “Elastoviscous properties of polyisobutylene (and other amorphous polymers) from stress-relaxation studies. IX. A summary of results.” J. Polym. Sci., 19, 111–121.
Chanda, M., and Roy, S. K. (1993). Plastics technology handbook, 2nd Ed., Marcel Dekker, New York.
Chevron Phillips. (2002). “Engineering properties of marlex resins.” Technical Service Memorandum No. PE TSM-1, The Woodlands, Tex.
Chua, K. M., and Lytton, R. L. (1989). “Viscoelastic approach to modeling performance of buried pipes.” J. Transp. Eng., 115(3), 253–269.
Hashash, N. M. (1991). “Design and analysis of deeply buried polyethylene drainage pipes.” Ph.D. dissertation, Univ. of Massachusetts, Amherst, Mass.
Husted, J. L., and Thompson, D. M. (1985). Pull-out forces on joints in polyethylene pipe systems, A guideline for gas distribution engineering, E.I. Du Pont de Nemours & Co.
Janson, L.-E. (1985). “Investigation of the long-term creep modulus for buried polyethylene pipes subjected to constant deflection.” Proc., Advances in Underground Pipeline Engineering, J. K. Jeyapalan, ed., Pipeline Division of the ASCE, University of Wisconsin-Madison, Madison, Wis., 253–262.
Janson, L.-E. (2003). Plastic pipes for water supply and sewage disposal, 4th Ed., Borealis, Majornas CopyPrint AB, Stockholm, Sweden.
Kondner, R. L. (1963). “Hyperbolic stress-strain response: Cohesive soils.” J. Soil Mech. and Found. Div., 89(1), 115–143.
Moore, I. D. (1994). “Three dimensional time dependent model for buried hdpe pipe.” Proc., 8th Int. Conf. on Computer Methods and Advances in Geomechanics, H. J. Siriwardane, ed., Morgantown, W.Va.
Moore, I. D., and Hu, F. (1995). “Response of profiled high-density polyethylene pipe in hoop compression.” Transportation Research Record. 1514, Transportation Research Board, Washington, D.C., 29–36.
Moore, I. D., and Zhang, C. (1995). “Computer models for predicting hdpe pipe stiffness.” Proc., Annual Conf., Canadian Society for Civil Engineering, Ottawa, Ont., Canada, 565–574.
Morland, L. W., and Lee, E. H. (1960). “Stress analysis for linear viscoelastic materials with temperature variation.” Trans. Soc. Rheol., 4, 233–263.
Ogorkiewicz, R. M., ed. (1970). Engineering properties of thermoplastics, Imperial Chemical Industries Ltd., Plastics Division, Willey, New York.
Passaglia, E., and Knox, J. R. (1964). “Viscoelastic behavior and time-temperature relationships.” Engineering design for plastics, E. Baer, ed., Reinhold, New York.
Phillips Driscopipe, Inc. (1981). Driscopipe 8000, the super tough polyethylene piping system for gas distribution, Richardson, Tex.
Popelar, C. F., Popelar, C. H., and Kenner, V. H. (1990). “Viscoelastic material characterization and modeling for polyethylene.” Polym. Eng. Sci., 30(10), 577–586.
Popelar, C. H., and Evans, D. (2004). “Creep ovalization and buckling of a linear viscoelastic externally pressurized pipe.” J. Pressure Vessel Technol., 126(2), 208–215.
Popelar, C. H., Kenner, V. H., and Wooster, J. P. (1991). “An accelerated method for establishing the long term performance of polyethylene gas pipe materials.” Polym. Eng. Sci., 31(24), 1693–1700.
Stewart, H. E., Bilgin, Ö., O’Rourke, T. D., and Keeney, T. M.-J. (1999). “Technical reference for improved design and construction practices to account for thermal loads in plastic gas pipelines.” Final Rep. No. GRI-99/0192, Gas Research Institute, Chicago.
Tobolsky, A. V. (1960). Properties and structure of polymers, Wiley, New York.
Van Krevelen, D. W. (1976). Properties of polymers, their estimation and correlation with chemical structure, 2nd Ed., Elsevier, New York.
Williams, M. L., Landel, R. F., and Ferry, J. D. (1955). “The temperature dependence of relaxation mechanism in amorphous polymers and other glass-forming liquids.” J. Am. Chem. Soc., 77(3), 3701–3707.
Zhang, C. (1996). “Non-linear mechanical response of high density polyethylene in gravity flow pipes.” Ph.D. dissertation, The Univ. of Western Ontario, London, ON, Canada.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 19 • Issue 12 • December 2007
Pages: 1043 - 1052
Copyright
© 2007 ASCE.
History
Received: Aug 9, 2006
Accepted: Nov 7, 2006
Published online: Dec 1, 2007
Published in print: Dec 2007
Notes
Note. Associate Editor: Houssam A. Toutanji
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.