Plastic Pipes Conference Association # 2021 Amsterdam
Britta Gerets, Mirko Wenzel, Kurt Engelsing
The strain hardening test (SHT, ISO 18488 [1]) becomes increasingly important for the characterization of high-density polyethylene (HDPE) grades and pipes made thereof. With regard to small pipe diameters, a smaller test specimen than the one defined in ISO 18488 has been developed. SHT results were demonstrated to remain unchanged as long as the applied strain rate stays constant. With a succession of sawing, milling, grinding and finally punching, a procedure to extract specimens from pipes was developed. [2] In further work the procedure was optimized: Thin films, from which dogbone specimen can be punched directly, were generated on a lathe. This provides the additional benefit that specimens can also be extracted in circumferential direction. A variety of different HDPE pipe grades and pipe dimensions were tested and the SHT results were put in relation to those from material tests according to ISO 18488. Although the same material batch was used in both cases, differences between material and pipe test results were observed. [3] Therefore, the influences of pipe dimension and the pipe extrusion process were studied. Especially molecular orientation revealed a great impact on the SHT results.
Related papers
Author(s) : A. Taraiya, P. Degenhart, M. Soliman, M. Boerakker, R. Handstanger, R. Kleppinger
Since the introduction of polyolefins for pressure pipes, continuous improvements have been made to meet ever-higher demands on their performance and to expand their application window beyond their original scope, mostly based on new resin formulations. Today, we also continue to push the limit to provide better...
Author(s) : Derek Muckle
A technical program has been undertaken to provide evidence on the suitability of polyethylene pipe and fitting systems for the distribution of hydrogen fuel gas. The underlying principle has been to evaluate material in the form of a pipe and to consider the performance of the pipe and of the welded jointing systems...
Author(s) : Peter Hubbard, Linqing Luo, Andrew Yeskoo, Kenichi Soga, Krista (Moita) Araica, Gus Cicala, Marshall McLeod
Seismically active faults pose a risk to buried water pipelines that can be complicated to quantify. Fault type, slip rate, pipeline geometry, and soil conditions all factor into a complex soil-pipeline interaction. For critical pipelines that cross faults, high-density polyethylene (HDPE) has become an attractive...
Author(s) : Dominique GUEUGNAUT, Pascal AUSSANT, Romuald BOUAFFRE, Myriam BECHROURI
Concerns regarding the environment and sustainable development have revived interest in the reprocessing and re-use of polymer materials from manufactured objects that have reached the end of their operating life. Within this framework, formal professional agreements have been put in place at global level under the...
Author(s) : Paul J. Freudenthaler, Joerg Fischer, Mathias Eder, Reinhold W. Lang
For controlled water disinfection, typically chlorine is used and preliminary studies demonstrate its aging and crack growth acceleration effects on polyolefin pipe materials [1, 2]. Although the use of recycled plastics is not prohibited in some ISO standards for polyolefin piping systems [3–5], only small amounts...
Author(s) : Mike Troughton, Amir Khamsehnezhad, Changyi Yu
When butt fusion welding polyethylene (PE) pipes in the field, it is often specified that the pipes must undergo fusibility testing in all combinations of suppliers, diameters and thicknesses before being fused in production. This is a very onerous and expensive task, but must be carried out to ensure that the PE...
Author(s) : Shuhei Nishida, Shintaro Iwasaki, Hidefumi Yamanaka, Takahiro Kasatani
Polyethylene pipelines have been used for natural gas service applications for over 40 years in Japan. It is thought that they will continue to be used widely for many years. Therefore, it is important to confirm the conditions of the existing pipelines being used for the long term. In this study, polyethylene pipes...
Author(s) : Sjoerd Jansma, René Hermkens
More than 20,000 km of rigid PVC (or PVC-U) pipes are currently in use for the distribution of natural gas in the Netherlands. In this decade, the majority of these pipes will reach their initially specified lifespan of 50 years. In the light of a possible replacement surge, it is increasingly important to identify...
Author(s) : Ernst van der Stok
For PE 100-RC, two tests are still under development for pipes: the point load test (PLT) and the accelerated notch pipe test (aNPT). The PLT was developed by a project group consisting of manufacturers and end users. The PLT determines the resistance to point loads as they can occur in practice. An earlier study...
Author(s) : S. Nestelberger, J. Cheng
The Point Load Test (PLT) [ 1, 2] was designed to simulate the SCG (slow crack growth) failure initiated by a rock pressing into the exterior wall of a polymer pipe. Today’s PE materials sustain long PLT testing times, due to its high SCG resistance design. Consequently, an accelerated “PLT+” with the support of...
Author(s) : Stephan Kneck, Henrik Iskov
It has become ever clearer that the resources of natural gas are an energy source, which will be less important in the future due to limitations in use of natural reserves. In order to prepare for the future the gas industry is looking at the alternative fuel gases, one such fuel gas is hydrogen. In order to prepare...
Author(s) : Mario Messiha, Britta Gerets, Jan Heimink, Andreas Frank, Florian Arbeiter, Gerald Pinter
A majority of field failure of viscoelastic plastic pipes can be attributed to slow crack growth (SCG) and has become crucial in terms of characterization of newly developed materials – particularly, if they are designed for pressurized pipe applications. In this study, investigations in terms of SCG resistances...
Author(s) : Suleyman Deveci, Nisha Preschilla, Sulistiyanto Nugroho, Birkan Eryigit
Carbon black (CB) has been used as a perfect and the cheapest solution to prevent photo degradation of polyethylene against UV light exposure. The effect of carbon black on the mechanical properties of polyethylene pipes was studied extensively, but only on well dispersed and distributed carbon black...
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) : Gisbert Rieß, Katrin Berger, Anna Kaltenegger-Uray, Florian Arbeiter
The effect of electron-beam and silane crosslink of polyethylene on the resulting permeation characteristics was investigated. Polyethylene sheets were processed and crosslinked by irradiation with high energy electrons and by grafting and subsequent hydrolysis of organosilanes during a reactive extrusion process. The...
Author(s) : Alex Stolarz, Klaus Grønnegaard Lauridsen
Low temperature District Heating – COOL DH – addresses the challenges of the upcoming decades in the energy sector for new housing developments. Energy efficiency is an important aspect of modern building construction. Improved building insulation and other technologies result in lower heat demand and enable new...
Author(s) : Ulrich Schulte, Dr. -Ing. Joachim Hessel
In order to protect the Austrian lakes effectively against the discharge of effluent, a 13 km long pressure pipeline made of high density polyethylene was laid on the bottom of Lake Ossiach back in 1971. The DN355 to DN200 pipes were produced from a first generation HDPE-compound. The classification would have been...
Author(s) : Xinwen Yu, Aimin Xiang, Dongyu Fang, Peck Tze Kang, Jinghui Li
The Chinese PE water pipe market has developed significantly in recent years and particularly over the last 12 months. Against a background of water scarcity and growing urbanization, this evolving market has grown significantly in both size and quality awareness. On the back of past experiences, a fundamental...
Author(s) : Justin Brandt, Mike Griffin, Tony Cuvo
As plastic pipe gains share in new markets and applications, additional joining methods add further value, enabling continued growth for plastic pipes. To date, definitions of a “fit-for-purpose” mechanical joint for High Density Polyethylene (HDPE) pressure piping systems can vary significantly. As such, mechanical...
Author(s) : Alireza Sahaf Amin, Dr. Gholamreza Pircheraghi
PE-Xa pipes used in the hot water supply are required for high mechanical strength and high creep resistance at high temperature. Because of the higher cross-link degree of PE-Xa pipes as compared with other crosslinked pipes methods , these pipes which are made by peroxide crosslinking have better performance in the...
Members of the Association
