Papers
Plastic Pipes Conference Association # 2014 Chicago
Dr. Z. Jimmy Zhou, Jim Johnston
Heat fusion joining method has been widely used for thermoplastic piping materials such as polyethylene to form the “one-material” pipeline system. No additional 3rd party materials such as an adhesive are needed. The fusion procedures to ensure the quality of the joints could be different for different materials and standards. ASTM polyethylene pipe heat fusion procedure in PPI TR-33 and ASTM F 2620 is not the same as the ISO procedure in ISO 21307. However, both fusion procedures have delivered high quality joints for about half century. While it is important to strictly following the fusion procedures, it does not mean that high quality joints cannot be obtained outside of the specified fusion temperature-interfacial pressure boxes in these two procedures. The questions therefore are raised that what is the fundamental basis behind these fusion procedures? Are these fusion procedures optimized? In addition to the procedure difference, different thermoplastic pipe have different material attributes to the quality of the joints. Semi-crystalline material is different from amorphous material. Due to the perception that the ability of heat fusion joining is a given feature to thermoplastic pipe, there are very limited researches for the essential variables of heat fusion joining of thermoplastic. The industry has focused on how to qualify the fusion procedures. In this paper, we will explore the material essential variables for heat fusion joining of thermoplastic pipe. Polyethylene pipe resin, as listed as PE4710, PE3608 and PE2708, is taken as a benchmark material. First, to form a joint that behaves like one uniform material, it is essential to have sufficient molecular chain entanglements and cocrystallization of the molecular chains from both sides of the pipe to be fused. Second, the melt flow behaviors as a function of temperature and shear rates are measured and modeled to understand the fusion procedures for various pipe diameters and wall thickness. Third, for a standard fusion procedure that is used for unimodal and bimodal polyethylene as well as high, medium and low density polyethylene, the essential material variables of these polyethylene materials must support the mutual heat fusion procedure. Both material characteristics and fusion procedure are critical to the quality of the joints.
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
HDPE Pipe holds a dominant position in several markets in North America: natural gas distribution, oil patch, mining, landfill and geothermal. So why are polyethylene’s municipal water and wastewater market shares so much lower than these other industries? How has the polyethylene industry been successful in growing...
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) : 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) : 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...
Author(s) : Dr. Holger Brüning, Serge Hascoët, Yann Delanne, Didier Nozahic, Jawdat Mansour, José Santana
RTE operates, maintains and develops the French electricity network, including the High and very High Voltage cable lines. Their network is the largest in Europe and includes over 6400 km of underground HV links operated in 2018. The company is modernizing and developing its network by investing 1.5 billion euros per...
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) : Greg Scoby, PE
This paper will detail the steps taken during adoption of HDPE for potable water systems improvements including material justification, creation of related specifications, investigation of available piping components, qualification of contractors and the construction/inspection of related systems. The City of...
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) : M. Eckes & Dr. B. Baudrit, Dr. M. Troughton & D. Wylie, H. van Laak & J. Fritz
Unplasticized polyamide 12 (PA-U12) is increasingly being used in pipe applications, especially in the gas sector. However, the material behavior in the usual quality tests for pipe welds has not yet been thoroughly investigated. For this reason, two research institutes, worked in cooperation with a manufacturer of...
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) : 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...
Members of the Association
