2018 Las-Vegas : Chlorine dioxide resistant HDPE mechanism, analytical tools and solutions
Author(s) : M. Boerakker, S. van Mierloo, D. v. Beek, R. Schipper, P. Voets, M. Soliman, K. Jacobson, D. Lukes, B. Rabaud, F. Zraick
HDPE pipes are used for standard pressurized water pipes, offering an excellent solution for safe transport of (drinking) water. The HDPE pipe market is growing globally. Especially in countries that suffer from water scarcity, surface water and water from rivers have to be used for drinking water supply. To guarantee...
2018 Las-Vegas : Determination of the slow crack growth resistance of PA12 pipe grades
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...
2018 Las-Vegas : Testing parameters influencing the strain hardening modulus
Author(s) : E.J.W. van der Stok
The effect of eleven different test parameters on the strain hardening modulus was investigated using the Design of Experiments statistical method. The changes in strain hardening modulus due to temperature, tensile drawing speed and the cooling rate after annealing were assessed. The importance of taking account of...
2016 Berlin : Can PE and PVC gas distribution pipes withstand the impact of sustainable gases?
Author(s) : René Hermkens, Ernst van der Stok, Johannes de Bruin, Jeroen Weller
The replacement of fossil fuels like natural gas by sustainable gases such as biogas and hydrogen can mitigate global warming. There has been some debate about the impact of sustainable gases on the materials used in the gas grid. An extensive study of the behaviour of PE, PVC, POM and rubber materials was therefore...
2016 Berlin : Determining the residual quality of PE pipes using the strain hardening test
Author(s) : Ernst van der Stok, Frans Scholten
Samples machined directly from pipe show that orientation has a large influence on the strain hardening modulus. No effects arising as a result of residual stresses were found. Samples machined in the axial direction from a hydrostatic pressurised pipe showed no effect as a result of this mechanical degradation. For...
2016 Berlin : Predicting the lifetime of PE50 gas pipes under point loading
Author(s) : Frans Scholten, Ernst van der Stok
The residual quality of first generation PE50 gas pipes, installed in Netherland between 1961 and 1979, is still remarkably good. The only premature failures of a few PE50 pipes were exclusively caused by point loads. When under point loading, they started failing in practice after 8 to 26 years, in a brittle manner....
2016 Berlin : Residual quality of excavated UPVC gas and water distribution pipelines
Author(s) : Frans Scholten, Ernst van der Stok, Britta Gerets, Mirko Wenzel, Mike Boege
The current condition of 35-50 years old uPVC main (110 mm) and service (32 mm) pipes for gas and water distribution was assessed. From 27 excavation sites in total about 400 segments of 1.2 meters length each were tested using many techniques. The K-value (average molecular weight) of the PVC, the degree of gelation...
2016 Berlin : The european plastic pipes industry - Recycling commitment
Author(s) : Tony Calton, Roel van’t Veer, Henk Meerman
The European plastic pipes and fittings industry has made a commitment through TEPPFA to use a quarter of a million tonnes of recycled material a year by 2020.
This presentation provides background to the growth in the use of recycled material for pipe applications and outlines some of the achievements to date and the...
2016 Berlin : Total overview of developments in PVC-O in size and couplers.
Author(s) : Paul van Doesburg, Berend Stel, Rob Spekreijse
PVC-O is the accepted pipe solution for the future. Worldwide, more and more countries go in the direction of PVC-O. The main applications for PVC-O at this moment are potable water, wastewater, irrigation and gas.
PVC-O is produced for many years from the 80’s until 2007 the sizes were in majority small (mainly...
2014 Chicago : Designing Against Rapid Crack Propagation in PVC Water Pipes
Author(s) : Frans Scholten, Ernst van der Stok, Jan Breen
Very occasionally PVC-U water pipes suddenly fail due to a long brittle crack with a length of many meters which propagates with the speed of sound along the pipe and causes extensive water loss. This phenomenon has been recognized as Rapid Crack Propagation (RCP). The conditions under which RCP can occur are an...
2014 Chicago : Two Complementary Tests to Determine the Quality of PE 100RC
Author(s) : Ernst van der Stok, Frans Scholten
The Strain Hardening (SH) test and the Point Load Test (PLT) are two complementary tests designed to determine the quality of PE 100-RC. The SH test is a resin test, whereas the PLT is a pipe test. The SH test is a tensile test performed at 80 °C. Extensive research on the SH test has been conducted and published in...
2012 Barcelona : Strain hardening tests on PE pipe materials
Author(s) : Van der Stok, Scholten
The Strain Hardening (SH) test developed by Kurelec et al. has been applied to a variety of PE pipe and resin materials. The clear trend in the strain hardening modulus, of first, second and third generation PE pipe resins and PE100 RC pipe resins, illustrates the large progress in resin quality during the past four...
2010 Vancouver : Cover blow-off resistance of reinforced thermoplastic pipes for gas service
Author(s) : E.J.W. van der Stok, F.L. Scholten, L.G.P. Dalmolen
A mathematical model was set up to assess the equilibrium gas pressure in the annulus of the
reinforcement layer of an RTP pipe. This is done by using the theory of gas permeation, ruled
by Fick's Law and the theory for a temperature gradient over the pipe wall, ruled by Fourier's
law. The model allows calculating the...
2004 Milan : Polybutene-1 - Entering the Next Generation
Author(s) : Schemm, Van de Vliet, Koennecke, Grasmeder
Polybutene-1 (PB-1) is a relatively unexplored polyolefin which shares many features in common with
conventional polyolefins like polypropylene and polyethylene, while at the same time offering
versatility, value and opportunity through a range of properties not usually associated with this type of