Design of large diameter buried pipes

 

Papers # 2018 Las-Vegas

The behavior of buried plastic pipes is already well described in standards and technical specifications and as well as proven in real life conditions. Plastics pipes in diameters up to around 400 mm are already in use for more than 60 years and pipes with larger diameters for more than 20 years now. All with good experience. However, the pipe market is conservative and the advantages of flexibility in especially large diameter buried pipes are still not recognized in all countries. This study brings more evidence and will help to an even broader acceptance of the use of plastic pipes – especially in large diameters.

In the late nineties TEPPFA carried out a study into the behavior of buried thermoplastics pipes. 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 involved as consultants in the project. The experimental work included a number of less ideal installation circumstances, in order to fully understand where the border line of safe installations is by predicting the performance of the buried pipes. Parameters, like depth of cover, pipe stiffness, installation quality and pipe material’s creep ratio have been studied. 

A report that summarized the experimental work carried out was issued including an analysis of the pipe soil interaction process as it was monitored during the study. Next to that a simple design graph explaining the short and long-term deflection as a function of the pipe stiffness class and the quality of the installation. The results have been presented at the Plastic Pipe Conference /3/, /4/ and in magazines /5/ as well as it is being used in standardization work, e.g. in developing CEN TS15223, “Validated design parameters of buried thermoplastics piping systems”.

Although the physical rules stay the same the world has changed. The need for water tight solutions in large diameter drainage and sewer pipes has given plastic pipe solutions a significant increase in market share in Europe, very well supported by the introduction of the EN 13476 standard which describes a number of different ways to design and produce a structured-wall pipe. TEPPFA has therefore decided to extend that Buried Pipe Study by adding field test and measurements of large diameter structured wall pipes in order to enhance the scope and the validity of the earlier results to those bigger diameters. With the knowledge from the earlier TEPPFA project, in which it was shown that the material’s creep ratio is not an important parameter, it was decided to do all tests with PE structuredwall pipe because of its availability at the site.

A test in Denmark has been executed and SN2 and SN4 PE pipes according to EN13476 has been installed under “Good”, “Moderate” and “Poor” conditions. The soil used has been poorly graded sand / silt mixtures which allows the poor installation. If a rather freefloating uniform backfill would have been used, it would be difficult to create poor installations. The deflection has been measured after assembly but before backfilling and then again after backfilling and completion of the installation. Measurement has been repeated after 10 weeks and 19 weeks. It is planned to continue measuring according the results observed. An older test installation in Finland on the property of Uponor in Vaasa has been included in the project as well. This test installation is affected by severe traffic load.

Related keywords : Buried Pipes, Installation, Compaction, Defection, Stiffness Class, Traffic load.
Please note that the whole article content is available on PPCA website only


Related papers

2018 Las-Vegas : Accelerated pipe test methods to evaluate PE 100-RC materials - Possibilities for iso standardisation

Author(s) : Thomas R. Kratochvilla, Raimund Eremiasch, Christoph Bruckner

In the last years effort has been made to develop and standardise new accelerated test methods to evaluate PE 100-RC materials in short times in form of test bars. The two most important developments, the cracked round bar test (CRB test) and the strain hardening test (SH test) were published as final ISO standards in...

2018 Las-Vegas : Aging mechanism of polyethylene pipe material in chlorine dioxide and hypochlorite solution

Author(s) : Márton Bredács, Andreas Frank, Amaia Bastero, Alex Stolarz, Gerald Pinter

Accelerated aging experiments by the immersion of a commercial polyethylene (PE) pipe grade in 10 ppm of chlorine dioxide (ClO2) and in 100 ppm of hypochlorite (HOCl) solution at 60 °C were performed. An additional immersion test was conducted in 1 ppm of ClO2 at 40 °C. The exposure parameters were continuously...

2018 Las-Vegas : Assessing the remaining service lifetime of PE pipes: an australian case study

Author(s) : Nolene Byrne, Rasike De Silva, Keith Lenghaus, Tim Hilditch

Plastic pipes have been utilized in the Australian gas distribution network since the early 1970s. The most common plastic type found in Australia is polyethylene (PE), although nylon is extensively used in New South Wales. Early installation of PE pipe was completed using the first generation high density type PE50...

2018 Las-Vegas : C-PVC-O, pushing limits beyond in molecular orientation

Author(s) : Ignacio Muñoz

During the last years PVC-O has become a popular product in pipe business due to the huge improvements of mechanical properties of PVC after orientation. At the same time, CPVC has become an important choice for hot water conduits in in-house applications. Molecor has started a research program to evaluate the...

2018 Las-Vegas : Discover: plastics

Author(s) : Davidovski Zoran

To get a deeper insight in why plastic pipes systems in some cases are deselected by designers, installers and users, European Plastics Pipes and Fittings Association (TEPPFA) initiated a research including interviews in four pilot countries: Poland, France, Germany and the UK. The first phase was concentrating on...

2018 Las-Vegas : Effect of eccentricity on the measurement of hydrostatic pressure resistance of plastic pipes

Author(s) : Suleyman Deveci, Birkan Eryigit, Senthil K. Kaliappan

The effect of eccentricity on the failure time of pipes under hydrostatic pressure test has a significant magnitude that it can easily mislead the evaluation of pipes according to requirement of ISO 4427-2. Therefore, authors propose a maximum relative eccentricity limit of 0.015, even lower, for pipes being tested...

2018 Las-Vegas : Innovative millimeter waves technology for measuring diameter, ovality, wall thickness, and sagging of large plastic pipes

Author(s) : Christian Schalich

This paper introduces a new technology based on millimeter waves. It provides a noncontact, non-destructive, online measurement of inner and outer diameter, ovality, wall thicknesses, and sagging (sagging of the melt during solidification at a too high viscosity) of large plastic pipes during the extrusion...

2018 Las-Vegas : Introduction of large dia profiled PE/PP pipes for innovative piped distribution network (PDN) for irrigation in India

Author(s) : C. B. Dandekar

Agriculture is the major occupation practiced in India, and irrigation is therefore a vital part of the entire water budget of the country. India possesses only 4% of the total world’s fresh water resource, of which, more than 80% is consumed solely in the Agriculture Sector (Dhawan, 2017). Canal based distribution...

2018 Las-Vegas : Large diameter spiral wound pressure pipes

Author(s) : Bülent Kuzkaya

Spiral wound pipes are becoming more and more important in larger diameter HDPE pipe production technology. The spiral wound structured wall pipes with profiles are already well known and used for several low or non-pressure pipe applications. This paper shows that spiral wound pressure pipes can fulfill the...

2018 Las-Vegas : Multilayer polymer pipes - Possible utilization of recycled material

Author(s) : Pavel Hutar, Jan Poduska, Pavol Dlhy, Andreas Frank, Jaroslav Kucera, Jiri Sadilek, Gerald Pinter, Lubos Nahlik

This paper investigates possible use of recycled material as a part of a multilayer polyethylene pressure pipe system. Crack propagation in different configurations is simulated. Lifetimes of pipes containing recycled material are calculated. Results are compared with lifetimes of pipes made of virgin...

2018 Las-Vegas : New crosslinked (PEX) pipes from sustainable resources

Author(s) : Jacob John, Andrew J. Ortquist, Mats Thunwall, Patrik A. Roseen

This study investigates production of crosslinked polyethylene (PEX) pipes using a resin obtained from a renewable resource via twin-screw extruder technology. PEX pipes were extruded using petroleum-based and renewable high-density polyethylene (HDPE) for comparison. Testing using relevant ASTM standards on the new...

2018 Las-Vegas : New discoveries in stabilizing drinking water pipes in contact with chlorine dioxide

Author(s) : J.D. Kim, S. Kim , T. Schmutz, C. Malchaire, D. Scholz, K. Keck

Since a few years, pipe producers are facing the challenge to protect their plastic pipe from degradation due to chlorine dioxide. Unfortunately, most existing stabilization solutions are not effective enough to insure the desired lifetime of the material. This study shows how the latest development allow to top-up...

2018 Las-Vegas : Performance of large marine HDPE pipes during the submersion as based on laboratory testing

Author(s) : Ilija Radeljic, Ingemar Björklund

Installations of solid wall HDPE pipes are becoming more difficult and riskier with the increase in diameter (OD2000+ mm), length of strings (1000+ meters) and reduction in the wall thickness (SDR26-30). To gain a better understanding of the limits of the final pipe assembly prior to the sinking, a laboratory tests in...

2018 Las-Vegas : Polyolefin pipes in the middle east- today and tomorrow

Author(s) : Robert Lawrence, Mohana Murali

The paper covers the growth of the polyethylene pipe sector in the Middle East from the 90s to the present. The initial slow uptake was related to ignorance of the material properties from the end users through to designers and installers. Recently the Middle East has become a world leader in the use of ever larger...

2018 Las-Vegas : Product environmental footprint (PEF) method compared with environmental product declarations (EPDS)

Author(s) : Ludo Debever, Peter Sejersen, Carolin Spirinckx

Until today there are various ways of demonstrating the Environmental Performance of products, such as Life Cycle Assessments (LCA), Life Cycle Impact Assessments (LCIA), Environmental Performance Declarations (EPDs). The methods to obtain the result, however, can vary from country to country and can be interpreted...

2018 Las-Vegas : Rehabilitation of abandoned dn1000mm steel pipe with PE100 in malaysia

Author(s) : KianLin Ng, WengKeong Tan, KumHoong Lou

Heavy and constant trucked container traffic combined with an accelerated ground settlement in a coastal reclaimed land caused a DN1000mm cement-lined mild steel water pipeline that crossed under it to sink by more than 6m from its original buried depth. This then caused the internal & external cement lining to...

2018 Las-Vegas : Study on the resistance to external pressure test methods of plastic inspection chambers

Author(s) : Zhang Wei, Wei Ruoqi, Zhou Minghong, Zhou Mingwei,

This article gives a brief introduction of plastic inspection chambers in China. It focuses on the formulation of China's national standard for plastic inspection chambers and conducts the theoretical analysis and data validation of the key technical metrics in the standard for the following three tests: the...

2018 Las-Vegas : Taking polyethylene (PE) pipe to new heights ... and new diameters!

Author(s) : Norbert Jansen, Albert Lueghamer

Demand for polyethylene (PE) pipe continues to grow on a global basis. The performance properties of this tough, durable piping material are widely recognized by the engineering and design community on a worldwide scale and the range of applications expands. The evolutionary trend in PE piping systems has been very...

2018 Las-Vegas : The world's first class 3 safety related nuclear PE4710 piping project - 10 year review

Author(s) : Lonnie Corley, Dane Chang, Harvey Svetlik, Matt Brandes, Thomas Musto, Frank Schaaf, David Fink

This paper presents a brief overview of a challenging project at the Callaway Nuclear Power Plant where HDPE was utilized to replace degraded steel buried piping in a Safety Related water system. Callaway was the first Nuclear Power plant to obtain NRC approval and successfully place the HDPE piping system into...

2018 Las-Vegas : With PE-RT (polyethylene of raised temperature resistance) new applications in demanding oil & gas applications can be realized

Author(s) : Alex Stolarz

THE PE-RT TECHNOLOGY HAS EVOLVED SINCE IT HAS BEEN FIRST INVENTED AND INTRODUCED TO THE MARKET IN 1982. AN ESTABLISHED TECHNOLOGY FOR HOT AND COLD WATER PIPES USED IN DOMESTIC APPLICATIONS HAS POSITIONED ITSELF WELL WITHIN OTHER MATERIALS DUE TO THE COST EFFICIENT PROCESSING, HANDLING AND PRODUCTION OF PIPES. RECENT...

Members of the Association

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