Comparison of accelerated tests for PE grades lifetime assessment [PE]

Author(s) : Márton Bredács, Andreas Frank, Amaia Bastero, Alex Stolarz, Gerald Pinter

Accelerated aging experiments by the immersion of a commercial polyethylene (PE) pipe grade in 10 ppm of chlorine dioxide (ClO2) and in 100 ppm of hypochlorite (HOCl) solution at 60 °C were performed. An additional immersion test was conducted in 1 ppm of ClO2 at 40 °C. The exposure parameters were continuously...

Author(s) : Gerald Pinter, Florian Arbeiter, Johannes Wiener, Andreas Frank, Otmar Kolednik

In order to further increase the fracture toughness of pipes, biomimetic layer design of the pipe wall can be used. Therein, soft polymer interlayers can act as crack-arresters in a matrix of stiffer and inherently more brittle polymers. The effectiveness of the crack arresting role of soft interlayers in a...

Author(s) : Mario Messiha, Andreas Frank, Isabelle J. Berger, Jan Heimink, Hermann van Laak, Florian Arbeiter, Gerald Pinter

Since the last decade polyamide 12 (PA12) has been successfully introduced as material for SDR 11 gas piping systems up to 18 bar, representing itself as an attractive alternative to steel pipes for high-pressure applications. Practical experience has confirmed that beside the higher strength, PA12 pipe grades also...

Author(s) : Isabelle J. Berger, Andreas Frank, Gerald Pinter, David Nitsche, Dirk Petry

Electrofusion (EF) sockets constitute a well-established and practically proven technology for the joining of polyethylene (PE) pressure pipes. As for the pipes, the potential lifetime of such welding connections is beside other properties also depending on the resistance against slow crack growth (SCG). The current...

Author(s) : Pavel Hutar, Jan Poduska, Pavol Dlhy, Andreas Frank, Jaroslav Kucera, Jiri Sadilek, Gerald Pinter, Lubos Nahlik

This paper investigates possible use of recycled material as a part of a multilayer polyethylene pressure pipe system. Crack propagation in different configurations is simulated. Lifetimes of pipes containing recycled material are calculated. Results are compared with lifetimes of pipes made of virgin...

Author(s) : Juergen Wuest, Benjamin Baudrit, Frank Dorbath, Christopher Pommer

A testing apparatus for determining the mechanical properties of electrofusion and heated tool sleeve welded joints with the mechanized linear shear test (LST) was developed. The LST-apparatus allows the recording of the force as a function of the extension / shear length. It has been proved that the linear shear test...

Author(s) : Andreas Frank, Isabelle J. Berger, Mario Messiha, Carl-Gustaf Ek, Norbert Schuler, Jens-Martin Storheil, Erwin Mayrbäurl, Steve Heeley, Frank Krause, Lodewijk Niemöller, Philippe Gabriëls, Yogesh S. Deshmukh, Florian Arbeiter, Thomas Koch, Gerald Pinter

In order to improve the circular economy of polymers in terms of sustainability and reduced carbon footprint, the increased use of recyclates has become a topic of major importance. Due to their long design lifetimes, pipe applications represent an excellent opportunity to create added value to non-virgin polymers. In...

Author(s) : Juergen Wuest, Mirko Wenzel, Andreas Bilsing, Peter Postma, Werner Wessing

Within the scope of a DVGW (German Technical and Scientific Association for Gas and Water) research project the technology of squeezing-off for PE pipes at operating pressures higher than 1 bar and the extension to new materials with higher operating pressures were investigated. For this purpose the tightness of the...

Author(s) : Lonnie Corley, Dane Chang, Harvey Svetlik, Matt Brandes, Thomas Musto, Frank Schaaf, David Fink

This paper presents a brief overview of a challenging project at the Callaway Nuclear Power Plant where HDPE was utilized to replace degraded steel buried piping in a Safety Related water system. Callaway was the first Nuclear Power plant to obtain NRC approval and successfully place the HDPE piping system into...

Author(s) : Amaia Bastero, Márton Bredács, Andreas Frank

The effect of chlorinated water environment to plastic pipes has been intensively investigated in recent years and proved to affect the lifetime of plastic pipes. Since it is known that the use of the different disinfectants (ClO2, HClO/ClO- ) imply different degradation rates, understanding the conditions...

Author(s) : G. Pinter, F. Arbeiter, A. Frank

The cyclic cracked round bar test has recently been added as a full-fledged ISO standard (ISO 18489) for comparison of polyethylene pipe grade materials’ slow crack growth resistance. However, possibilities of this test are yet far from being exhausted. Seeing, that polyethylene is only used in approximately 30% of...

Author(s) : Márton Bredács, Anita Redhead, Andreas Frank, Amaia Bastero, Gerald Pinter

To maintain the high quality of potable water chlorine based disinfectants are frequently dosed into the drinking water network. Considering the oxidative nature of these species their long-term impact on the aging of polyolefin pipes is a matter of interest. In this study four polyolefin pipe grades were objected to...

Author(s) : Andreas Frank, Isabelle J. Berger, Florian Arbeiter, Pavel Hutař, Gerald Pinter

Due to the high slow crack growth resistance of modern polyethylene pipe grades a reliable lifetime assessment of pipes with focus on stage II failure has become challenging. The current paper presents a scientific approach for a fracture mechanics lifetime prediction based on Cyclic Cracked Round Bar (CRB) Tests....

Author(s) : Univ.-Prof. DI Dr. mont. Gerald PINTER, DI Florian ARBEITER

Applying scientifically well established and investigated linear fracture mechanic methods (LEFM) the kinetics of the slow crack growth (SCG) on polypropylene layers and coextruded interfaces on multi-layer-pipes could be investigated. Taking effects of ageing and stress relaxation during the service lifetime into...

Author(s) : Pavel Hutař, Jan Poduška, Jaroslav Kučera, Eva Nezbedová, Andreas Frank, Jiří Sadílek, Gerald Pinter

Residual stresses can significantly influence the lifetime of polymer pipes. Therefore, realistic estimation of residual hoop stress can contribute to accurate lifetime estimations. The previously used “accurate method” is quite time consuming and needs a lot of specimens to be prepared and treated. A simplified...

Author(s) : Dr Predrag Micic, Mr Gerald Beckton

The urgent diversion of a river through a rapidly constructed pipeline was required to avert a power supply crisis to the state of Victoria. In early June 2012, the Morwell River surged and a levee collapsed allowing the river to flow directly into the open cut coal mine which supplies the Yallourn power station. The...

Author(s) : Frank W. O’Callaghan, Todd Randell

Building new pipeline infrastructure in highly congested urban environments is causing some interesting challenges for New Zealand engineers and construction companies, demanding innovative new pipeline solutions. The Birkdale area in the former North Shore City, now part of Greater Auckland City, New Zealand...

Author(s) : Andreas Frank, Isabelle J. Berger, Florian Arbeiter, Gerald Pinter

During the past years the Cyclic Cracked Round Bar (CRB) Test has been developed and meanwhile standardized as a new and modern test method for a quick material ranking of polyethylene pipe grades by their resistance against slow crack growth (SCG). As an additional benefit this test method allows a very precise...

Author(s) : Gerald Pinter, Florian Arbeiter, Isabelle J. Berger, Andreas Frank

An extrapolation to static conditions for an accelerated fracture mechanics lifetime prediction of pressurized polyethylene pipes was conducted. The main objective of the current paper was to correlate predicted pipe lifetimes to real failure times determined with internal pipe pressure tests and to study the...

Author(s) : Frank W. O’Callaghan

Functioning pipeline systems are a cornerstone of urban human communities, to bring in the clean water on demand for drinking, washing and sanitary needs, and in turn remove the used water from drains, waste, and stormwater sources. If the pipe system is suddenly rendered non-functional, such as by seismic event;...