Posters
Plastic Pipes Conference Association # 2014 Chicago
Ernest Lever
The Popelar bidirectional shift factors have been now been used about a quarter century to great effect. The question has been raised as to whether the shift factors are applicable to modern materials. GTI has been using rheological principles and Dynamic Thermo Mechanical Analysis (DTMA) to routinely develop bi-directional shift factors for PE, PB, PEX and EPDM materials. These shift factors have been correlated to Rate Process Method (RPM) testing of several of these materials and have been shown to be consistent with the RPM method. This paper will discuss the results and the variability of the shift factors across generations of PE material. In addition the paper will present an interesting method of how to use the confidence levels provided by the DTMA method to properly quantify the results of limited validation testingof PE pipe and fittings.
Mavridis provides a methodology to develop bi-directional shift factors based on rheological principles. The test methodology employed is Dynamic Thermo-Mechanical Analysis. Horizontal activation energies are calculated by fitting an Arrhenius type model to the tangent of the loss modulus as a function of excitation frequency and test temperature. The vertical activation energy is extracted from a model fitting the tangent of the loss modulus to the complex modulus as a function of excitation frequency and temperature. This method is very convenient as results can be generated in a few hours. The simplicity and low cost of the method enables us to test a sufficient number of replicates to generate statistical confidence limits on thecalculated activation energies.
In this paper the bi-directional shift factors are compared to the Popelar shift factors as described in [2-4]. It is first shown that the Popelar shift factors are closely replicated for vintage Aldyl A materials. Several modern materials were evaluated using the Mavridis methodology and the implications of the difference between the Popelar bi-directional shift functions and the measured bi-directional shift functions are discussed.
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) : Drew Mueller, Peter Dyke
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Author(s) : Chris Ampfer, Gene Palermo, Ernest & Oren Lever
This paper looks at the origin of the 10% allowable scratch depth rule for polyethylene (PE) pressure pipe developed in 1971 and research that has been performed over the years since its inception to determine the validity of this rule. The 10% rule has been used by natural gas pipeline operators since the 1970’s to...
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) : Lei Wang, Guozhi Xu, Qiaoping Qiu, Weihua Lu, Yanwang Han
PP-R (random copolymerized polypropylene) has been widely used in hot and cold water systems. However, the standard PP-R pipes have the disadvantages of a large high-temperature thermal expansion coefficient, an insufficient notched impact strength, and a low temperature and pressure resistance. In this paper, a new...
Author(s) : Ilija Radeljic, Ebbe Smith
HDPE pipe can be relatively easily scratched during the manipulation on the site, which is especially true for the marine pipelines. Installing the scratched marine pipe with the S bend method presents a risk and repair methods are usually performed. Currently, there is no standard defining the repair procedure, in...
Author(s) : Anja Armani, Helmut Zanzinger
PE-pipes are used in applications at temperatures higher than 40°C and long service lives like drainage pipes in landfill basal lining systems, drainage pipes in tunnels with high cover heights, geothermal applications, power plant technology, mining, underground cable protection pipes for power lines for...
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
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Author(s) : James F. Mason, Akshay Ponda, Hermann van Laak, Buc Slay
The effects of liquid hydrocarbons on long term strength of pipe grade thermoplastic resins is an important consideration when designing pressure pipe for use in the oil and gas industry. There is an extensive body of work going back several decades descri bing these effects for pipe grade polyethylenes, and all...
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) : Amster Howard
Flowable fill is used for many applications, but mainly for pipe trench embedment and backfill. There are three ways that using flowable fill can be kind to the environment. Because flowable fill is self-leveling and has a strength greater than the native soil, the trench cross section can be minimized. This means...
Author(s) : Gerald Pinter, Johannes Wiener, Florian Arbeiter, Abhishek Tiwari, Otmar Kolednik
For pipe applications, catastrophic failure due to crack growth has to be prevented by all means. Techniques to develop new and even tougher pipe materials are explored in this contribution. The aim is to create a multi-layer architecture, that exhibits high toughness as well as damage tolerance towards sharp notches....
Author(s) : Christian Schalich
Plastic pipes for infrastructure and building applications are precisely specified with regards to wall thickness and diameter. Pipe manufacturers use different measuring methods in order to ensure the required dimensional accuracy and maintain a constant high quality. This paper introduces a measuring system based on...
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) : White G. Jee, Wes Long, Marcello Russo
In 2018, the North American HDPE pressure pipe market experienced unprecedented demand and growth especially in the region of the Permian basin in west Texas. 1 As aninnovative means of increasing HDPE pipe supply in this region, the first modular mobile extrusion plant was moved to Pecos, TX. Using custom designed...
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) : Lukas Travnicek, Pavel Hutar, Jan Poduska, Andreas Frank, Florian Arbeiter, Jaroslav Kucera, Jiri Sadilek, Gerald Pinter, Lubos Nahlik
The application of recycled material in pressure piping systems has been considered lately – it was suggested, that the recycled polyethylene could be used as a part of a multilayer pipe together with virgin material. This type of pressure pipes is not availableon the market yet, so their properties can be only...
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...
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