S4 critical temperature tests: procedure and interpretation

Author(s) : Tom Stewart, Richard Hicks, Patrick Vibien, Lance MacNevin

Arguably, broadband technologies have become as vital to society as water delivery, waste removal and energy distribution. However, the role of plastic conduit in broadband is often overlooked within the piping industry and society in general. HDPE conduit is an essential component to the build -out of 5G cell...

Author(s) : Thomas R. Kratochvilla, Patrick Grünbeck, Christoph Bruckner, Raimund Eremiasch, Harald Wilhelm, Mario Vukelja

In the last decades pipe dimensions of extruded PE pipes have reached new orders of size. Today, PE pipes with outer diameters of up to DN/OD 3500 mm are produced and used for pressure pipe applications like seawater intake/discharge, outfall, sewage and industrial process piping systems. To test the long-term...

Author(s) : Patrick Campbell, Joanne Claronino, Shana Meeus, Joseph Sanders, David Chrystie-Lowe

Polyethylene (PE) potable water mains, with design life of 50 years (BS EN 12201), have been in widespread use in the UK water industry for more than 30 years. PE pipe is light, flexible and reliable in comparison with other pipe materials and the UK water industry has made a considerable investment in replacing...

Author(s) : Joerg Fischer, Paul J. Freudenthaler, Patrick R. Bradler, Reinhold W. Lang, Susan C. Mantell

This research addresses the effect of nucleation on the global aging behavior and the fatigue crack growth (FCG) resistance of commercial alpha- and beta-nucleated polypropylene random copolymer pipe grades (PP-R) when exposed to chlorinated water (5 mg/l free chlorine) at an elevated temperature of 60°C. Comparing...

Author(s) : Joerg Fischer, Patrick R. Bradler, Reinhold W. Lang

In the present paper, a novel test system for conducting fatigue crack growth (FCG) experiments under superimposed mechanical-environmental conditions is presented. FCG experiments were performed on a polypropylene (PP) grade and a short-glass fiber reinforced polyamide 66 (PA-GF) grade as model materials. The...

Author(s) : Joerg Fischer, Paul J. Freudenthaler, Patrick R. Bradler, Reinhold W. Lang

Cyclic tests with cracked round bar (CRB) specimens have been used for some time to characterize the slow crack growth behavior of polyolefin pipe grade materials. In fact, most recently a standardized test procedure for cyclic CRB testing has been released in ISO 18489. To obtain kinetic data for cyclic crack growth...

Author(s) : Joerg Fischer, Patrick R. Bradler, Reinhold W. Lang, Gernot M. Wallner

The present paper aims to study the crack growth resistance of a black-pigmented polypropylene pipe grade when exposed to elevated temperatures and various environmental media (air, deionized water, ionized water with a specific chloride content, and chlorinated water) under the simultaneous application of cyclic...

Author(s) : Reinhold W. Lang, Patrick R. Bradler, Joerg Fischer, Dominik Poehlmann, Steven Schmidt, Ansgar Niehoff

In the present paper, a highly effective test and characterization concept for polymer recyclate materials is proposed and validated. Based on the proposed methods, a study was carried out to investigate the potential of in-plant and post-use PE recyclates from various applications to be utilized in PE recyclate...

Author(s) : Rieky Steenbakkers, Linda Havermans, Patrick Voets, Jonathan Rabiei, Rudy Deblieck

The resistance to Slow Crack Growth of HDPE is related to the strain hardening modulus as determined from a tensile test at 80 °C. Correlatio ns between traditional methods (e.g. Full Notched Creep Test, Notched Pipe Test) and other accelerated tests (e.g. fatigue testing) show that the same failure mechanism is...

Author(s) : Dr. Ken Oliphant, William Luff, Dr. Peter Angelo, Patrick Vibien

Managing aging pipeline infrastructure is an important part of overall pipeline risk management. The critical risk management questions for an aging infrastructure are: how quickly should replacement occur and what parts of the system should be prioritized for replacement. To answer these questions it is necessary to...

Author(s) : Dr. Ken Oliphant, Patrick Vibien, Dr. Michael Conrad, Sarah Chung

A new methodology has been developed to validate the performance of polyethylene piping materials in potable water applications. The methodology is based on several research programs which examined a standardized accelerated test methodology (ASTM F2263 Standard Test Method for Evaluating the Oxidative Resistance of...

Author(s) : Dr. Ken Oliphant, Patrick Vibien

New and formal approaches to Asset Management (AM), such as the PAS-55 and ISO 55000 Asset Management standards have been developed over the past decade. These AM standards can be applied to pipelines and cover all stages of a pipeline's lifecycle - acquisition, operation, maintenance and renewal/disposal and provide...

Author(s) : GUEUGNAUT Dominique, ANGELINI Florent, BOUJLAL Adil, BOUAFFRE Romuald, SEVRE Bertrand, LOUET Patrick

Polyethylene (PE) is a widespread material for the manufacturing of gas and water distribution pipelines and a large number of PE electrofusion pipe joints can be found over the thousands of kilometres of PE pipeplines all over the world, thus generating an increasing interest in checking the quality of these joints....

Author(s) : Patrick Leevers, Christos Argyrakis

There is renewed interest in the correlation between critical pressures from lab-scale (S4) and full-scale RCP tests. The standard, supposedly material-independent correlation factor does provide a lower bound for data from many PE grades, but for some grades it is overconservative and for PA12 its applicability has...

Author(s) : P.Leevers

This paper outlines a PE100 design methodology which gives central importance to the separate modelling and measurement of plane-strain and plane-stress dynamic fracture resistance. The former is difficult to measure but can be estimated from weight-average molecular weight; the latter is related to high-rate adiabatic...

Author(s) : Krishnaswamy, Leevers, Lamborn, Sukhadia, Register, Maeger

The influence of molecular architecture on the rapid crack propagation (RCP) resistance of a wide variety of high-density polyethylene (HDPE) pipes was investigated. It was concluded that high molecular weight, high crystallinity and a relatively narrow molecular weight distribution are important architectural...

Author(s) : Leevers, Henderson, Pereira

Laboratory-scale S4 tests have been used to determine whether it would be possible, at any realistic working pressure, for a loosely-fitted PE liner within a rigid host pipe to fail by Rapid Crack Propagation (RCP). The standard ISO 13477 S4 method was modified by replacement of the containment ring cage by a rigid,...

Author(s) : Maeger, Vanspeybroeck, Lamborn, Mamoun, Leevers, Oliphant

As polyethylene pressure pipes enter the global marketplace under an ever-wider range of operating conditions, there is increasing emphasis on their rapid crack propagation performance. It is important that both producers and end-users are able to rely on the robustness of the rapid crack propagation test results and...

Author(s) : Ivankovic, Tropsa, Jasak, Leevers

This work presents a 3D coupled solid-fluid model for predicting fast failures in pressurised plastic pipes. It is developed within a unified computational procedure where both solid pipe and pressurising media are discretised using the Finite Volume method. The coupling is achieved across the pipe-fluid interface...

Author(s) : Leevers, Moreno, Paizis

The resistance of PE pipes to rapid crack propagation depends strongly on temperature. The critical pressure measured using ISO 13477 ‘S4’ tests increases abruptly above a transition temperature Tc. For PE100 grades Tc has become a primary index of quality : it must remain below 0°C despite a tendency to increase...