Our site uses cookies necessary for its proper functioning. To improve your experience, other cookies may be used: you can choose to disable them. This can be changed at any time via the Cookies link at the bottom of the page.


Predicting the lifetime of PE50 gas pipes under point loading

 

Frans Scholten, Ernst van der Stok

Papers # 2016 Berlin

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. The effect of point loads was modeled in order to help grid-owners to prioritize replacements.

Many Point Load Tests (PLTs) were performed using 8 mm indentation and a new Dehyton PL detergent on excavated, defect-free, 110 mm PE50 gas pipes. The influence of temperature (40, 60 and 80 °C), pressure and SDR (standard dimension ratio) was measured and later modeled using a multi-variate statistical model. The squared correlation coefficient (R2 ) was found to be favorably high: 0.940. For all three variables, the statistical probability (Pstat) of there being no correlation is favorably low (for all three variables <0.033), and lower than the requirement (<0.05). All three variables therefore have a separate effect on lifetime. 

The PLT model shows that a lower gas pressure reduces the effect of a point load and that thin-walled PE50 pipes fail sooner than thick-walled pipes, probably because in a thin-walled pipe a growing crack needs to travel a shorter distance through the wall until a leak is formed.

The acceleration factor in the PLT with Dehyton PL detergent with respect to water is 16. With this factor, the PLT model predicts a lifetime for PE50 pipes at 3 and 4 bars and 10 °C of 5 to 35 years, which is remarkably close to practice, demonstrating the value of the PLT model.

When, for the sake of argument, the LPL in ISO 9080 for PE50 pipes without point loads is extrapolated a failure time of about 4,300 years at 4 bars and 10 °C is calculated.

The time to failure in the PLT for PE80 pipes is 9 to 10 times longer than for PE50 pipes.

Related keywords : PE50, first generation, PE pipe, point load, lifetime, prediction.
Please note that the whole article content is available on PPCA website only

Related papers

2021 Amsterdam : A NEW GENERATION OF HIGH PERFORMANCE BIAXIALLY ORIENTED POLYETHYLENE AND POLYPROPYLENE PRESSURE PIPES

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...

2021 Amsterdam : A TRADE ASSOCIATION EXPLORED

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...

2021 Amsterdam : AN EVIDENTIAL APPROACH TO USE OF POLYETHYLENE PIPE FOR HYDROGEN FUEL GASES

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...

2021 Amsterdam : APPLICATION OF PP-R COMPOSITE REINFORCED PIPES IN HOT AND COLD WATER 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...

2021 Amsterdam : CHALLENGING THE 10% WALL THICKNESS RULE FOR HDPE MARINE PIPELINES

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...

2021 Amsterdam : DESIGN OF LARGE DIAMETER BURIED PIPES

Author(s) : Anders Andtbacka, Peter Sejersen

In the late nineties a study of the behavior of buried thermoplastics pipes was carried out. The project had input and participants from both the plastic pipe industry as well as from external organizations. Six external leading experts in the field of pipeline design, not necessarily plastics pipes design, have been...

2021 Amsterdam : DEVELOPMENT OF A RAPID AND INNOVATIVE IN-FACTORY PROCEDURE FOR TESTING THE PERFORMANCES OF PE PIPES CONTAINING VARIOUS PROPORTIONS OF RECYCLED POLYMER MATERIAL

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...

2021 Amsterdam : EFFECT OF CHLORINATED WATER ON THE FATIGUE CRACK GROWTH RESISTANCE OF POLYETHYLENE COMPOUNDS WITH RECYCLATE CONTENT FOR PIPE APPLICATIONS

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...

2021 Amsterdam : EXPERIMENTAL DETERMINATION OF THE EFFECTS OF LIQUID HYDROCARBONS ON THE LONG-TERM CREEP RUPTURE PROPERTIES OF PRESSURE PIPE GRADE UNPLASTICIZED POLYAMIDE-12

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...

2021 Amsterdam : FINDING THE RIGHT PIPE TEST FOR POLYETHYLENE WITH RAISED RESISTANCE TO SLOW CRACK GROWTH

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...

2021 Amsterdam : FINITE ELEMENT METHOD (FEM) USED TO SIMULATE THE STRESS/STRAIN OF THE POINT LOAD TEST (PLT) IN A BROADER STUDY TO SUPPORT THE FUTURE ISO TEST STANDARD

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...

2021 Amsterdam : FLOWABLE FILL FOR PLASTIC PIPE

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...

2021 Amsterdam : FROM MULTILAYER LAMINATES TO INDUSTRIAL PIPE APPLICATIONS – A GUIDELINE

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....

2021 Amsterdam : INNOVATIVE MILLIMETER WAVE TECHNOLOGY FOR MEASURING THE PIPE WALL THICKNESS EARLY IN THE EXTRUSION PROCESS

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...

2021 Amsterdam : INTAKE AND DISCHARGE LARGE DIAMETER PIPELINE PROJECT FOR COAL FIRED GENERATION PLANT IN JAPAN

Author(s) : Mitsuaki Tokiyoshi, Yuichi Shibao, Yoshitaka Watanabe, Takeshi Yoshioka, Takashi Oka, Kohei Sasaki

It was common to use those pipelines for Steel in Japan. However Steel pipes have the long standing problems that it has been needed maintenance costs for rust prevention and antifouling property. Therefore it had been carried out the project that large diameter polyethylene pipeline applied for circulating water...

2021 Amsterdam : MECHANICAL INTERGRITY OF HDPE BUTT FUSION JOINTS – EFFECT OF CARBON BLACK DISTRIBUTION

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...

2021 Amsterdam : MOBILE EXTRUSION TECHNOLOGY - A CASE STUDY USING INNOVATIVE MEANS OF ASSURING HDPE PIPE SUPPLY (IN BOTH THE PERMIAN BASIN OF WEST TEXAS AND THE MINING REGION OF CENTRAL FLORIDA)

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...

2021 Amsterdam : MULTILAYER POLYMER PIPES – THE INFLUENCE OF RESIDUAL STRESS ON FATIGUE LIFETIME

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...

2021 Amsterdam : NEW CHALLENGING APPLICATION AS USED PEAT LAND HIGH PERFORMANCE PE-SGF PIPELINE SYSTEM FOR INTERNAL PRESSURE APPLICATION AS LARGE DIAMETER

Author(s) : Kensei INOUE, Mitsuaki TOKIYOSHI, Joji HINOBAYASHI, Takeshi KARINO, Toshinori KAWABATA, Takashi KURIYAMA

As the worldwide problems are over-population, unusual weather like as localized heavy rain and climate change. Against those problem, it has to need new projects to make a new agricultural field, drainage pipeline system and to spread the new underground irrigation system at peat land whereas spots of about 2 million...

2021 Amsterdam : NEW CROSSLINKED POLYETHYLENE PIPES WITH HIGH THERMAL STABILITY AND LOW PERMEATION FOR PETROLEUM ENGINEERING

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

BOREALISBOROUGEFormosa Plastics CorporationHanwha TotalEnergiesINEOS O&PIRPCKazanorgsintez PJSCKorea Petrochemical IND. Co., LTD (KPIC)LyondellBasellPetroChina Dushanzi Petrochemical CompanyPRIME POLYMERSABICSCG Chemicals & Thai PolyethyleneSinopecTASNEE
TOP