Experimental Investigations of the Rapid Crack Propagation Performance of Polyethylene Pipes [PE]
# 2010 Vancouver
Good resistance to Rapid Crack Propagation (RCP) is considered to be important to the field
performance of polyethylene (PE) pipe. Even though RCP occurrences in PE pipe are very rare,
it remains important to understand the RCP phenomenon to ensure that pipes are designed to
avoid RCP events. The characterization of RCP performance depends on a variety of factors,
such as the test conditions (temperature and pressure), pipe geometry (diameter and wall
thickness), and choice of RCP test. Presented here are an accumulation of results from various
experimental programs undertaken by us to develop a basic understanding of RCP in PE pipes
and the test methods used to characterize RCP performance. Data are presented showing critical
pressure critical temperature failure surfaces for MDPE, HDPE, and bimodal HDPE pipe, and
their use in the selection of RCP resistant pipe based on specific service conditions is discussed.
Data are presented to demonstrate the phenomenon of false arrest and to show how this can lead
to misleading and incorrect interpretations of RCP performance from single-point S4 tests at
excessively high pressures. The results of experimental work to assess the influence of pipe size
on S4 test results are also presented. Analysis of these data, combined with consideration of the
effects of shear lips and residual stress effects, indicates that an Irwin-Corten relationship can be
employed to provide conservative estimates RCP performance for different size pipe, subject to
specific restrictions on the relative geometries between pipes.
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Author(s) : Vivek Rohatg, Gregor Hiesgen, Mark J. Lamborn, Ashish M. Sukhadia, Douglas E. Simpson, David W. Borrego, Pamela L. Maeger
Maintaining dimensions within specifications is problematic for the extrusion of large diameter thick-wall polyethylene (PE) pipe (> 75 mm wall) due to sag caused by insufficient resin melt strength. However, sag can be controlled through careful resin selection and optimization of the pipe cooling process. This paper...
Author(s) : Ashish M. Sukhadia, Mark J. Lamborn, Pam L. Maeger
Over the past several years, we have conducted extensive investigations of the Rapid Crack Propagation (RCP) behavior of Polyethylene (PE) pipes. While the typical data of interest is the Critical Pressure (Pc) and/or Critical Temperature (Tc), we chose to take our investigations further by exploring and generating...
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robustness of the rapid crack propagation test results and...
The crack growth rate in HMN 5202 and HXM 50100 polyethylcne has bcen studied as a function of
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