Author(s) : Schulte 2006 Washington DC
After the discovery of the low-pressure process for the production of polyethylene with the aid of Ziegler catalysts, only another year went by before pipes were being extruded in highdensity polyethylene. In the same year, at the end of 1954, Hoechst had already begun to carry out long-term failure tests on HDPE...
Author(s) : Wolters, Wikkerink 2006 Washington DC
The use of plastic pipeline materials in gas distribution systems is still increasing. Presently PE and high impact PVC are the dominating materials in gas distribution networks up to 4 bar. Most of these networks operate at these pressures, only a limited part of the network operates at higher pressures, up to 10 to...
Author(s) : Ewing, Greig, Stafford 2006 Washington DC
Funded by a UK government “Smart” Award, the authors have researched, and partially developed, a novel concept for temporarily reducing the external diameter of a PE pipe and then allowing recovery to full diameter as a close fit within a host main. The novelty lies in the four-lobed collapsed pipe geometry, which...
Author(s) : Lang, Pinter, Balika, Haager 2006 Washington DC
The current discussion and future situation in the field of polyethylene (PE) pressure pipes for water and gas supply may be characterized by the following aspects and topics. Continuous developments by polymer suppliers in the last decades have resulted in improved PE material grades, which in turn led to a...
Author(s) : Shumard, Fisher, Rahman 2006 Washington DC
Previous examinations of stresses in gasketed bell- and-spigot PVC pipe joints in North America have been limited to theoretical analyses and finite element evaluations, with the results relying on basic assumptions and observations. The objective of this study is to provide an accurate picture of the relative...
Author(s) : Corleto 2006 Washington DC
An accelerated method of determining the failure time of a polyethylene resin has been developed. The method requires determination of the minimum displacement rate, or the time at minimum displacement rate, using ASTM F 1473-01, followed by one of these procedures : (1) If failure has not yet occurred, cryogenically...
Author(s) : Christodoulou, Wilson, Hunter, Bowman 2006 Washington DC
Polyethylene (PE) based and metallic pipe systems have been assessed for their ability to stop petrol migrating through the pipe wall, fitting or joint and into water contained within the pipe. A quantitative test was devised that is capable of distinguishing between the different pipe systems. Plain PE pipe...
Author(s) : Wolf, Akagawa, Nakamura, Patadia 2006 Washington DC
With support from natural gas utilities, the Gas Technology Institute and Polyamide 12 material suppliers, a project was developed to determine the suitability for use of Polyamide 12 natural gas distribution systems operating above the current 125 psig limit imposed on polyethylene systems. The projects goals are to...
Author(s) : Chung, Oliphant, Vibien, Zhang 2006 Washington DC
Disinfectants are commonly added to potable water to control bacteria, viruses, protozoa, algae and fungi which can potentially lead to waterborne diseases. The three most common disinfectants used for maintaining a disinfectant residual in North America are chlorine, chloramines and chlorine dioxide. While these...
Author(s) : Krishnaswamy 2006 Washington DC
A comprehensive analysis of ductile and brittle failures from creep rupture testing of a wide spectrum of HDPE pipes (PE-80 and PE-100 pressure rating) was conducted; the HDPE resins studied included those polymerized using chrome-oxide, Ziegler-Natta and metallocene catalyst technology. The analysis indicates that...
Author(s) : Nezbedova, Vlach, Knesl 2006 Washington DC
A multilayer pipe consisting of two different layers, namely of PE and PPH, was analysed. The relevant numerical model based on the Finite Element Method (FEM) was used to calculate the stress and strain distribution and to estimate the fracture characteristics. As variables the thickness of the material layers and...
Author(s) : Sandstrum, McKinley 2006 Washington DC
The market for high density polyethylene (HDPE) pipe continues to expand across a variety of end use applications. As this growth continues to accelerate, users within the market place have become more familiar with the traditional method of joining HDPE pipe, namely butt fusion, and have become more educated in the...
Author(s) : Soliman, Voets, Raven, Kleppinger, Ward 2006 Washington DC
The Leeds die-drawing process has been used to produce biaxially oriented polypropylene pipes with significant enhancement of hoop mechanical properties in terms of tensile modulus and tensile strength due to a unique orientation of the a-crystallites throughout their cross section. Pendulum impact tests and...
Author(s) : Alferink 2006 Washington DC
Plastics pipes products are more and more appreciated in sewer schemes throughout the world. The advantages of thermoplastics, like the good resistance against sewer environments and the possibility to built complete tight systems are many times the drivers to use thermoplastic pipes and chambers. Plastics chambers...
Author(s) : Falkowski 2006 Washington DC
Plastics were well known in plumbing in the middle of 30’s of last century. With development of production technology bigger pipe diameters became available in plastics as well. What was available in Western Europe in 50’s and 60’s was also available in CEE countries one decade later due to licenses or own technology...
Author(s) : Ariaratnam, Weaklend 2006 Washington DC
With an increase in trenchless methods being employed for the installation of natural gas lines in urban areas, unmarked sewer service laterals present a risk of accidental and unknowing crossbores with these distribution lines. While the physical damage to underground facilities is always unwanted, a cross-bored...
Author(s) : Zena, Connolly 2006 Washington DC
The selection of PVC resins for pipe extrusion is regulated by the Plastic Pipe Institute (PPI) in terms of inherent viscosity (I.V.), and is further mandated to be 0.88 to 0.96 for pressure pipe. In addition, there are cell classification requirements, a system that defines the minimum physical properties a pipe or...
Author(s) : Whittle, Pesudovs 2006 Washington DC
The process of extracting scrap plastics pipes from the demolition and construction waste stream in a major city is described together with a quantification of the proportion of the most common plastics pipe materials in the waste. The condition of the pipes and the methods used to turn them into a re-usable form is...
Author(s) : Troughton, Brown, Hessel, Piovano 2006 Washington DC
As part of the Polytec Systems European-funded project, electrofusion (EF) joints in polyethylene (PE) pipe, containing different flaws, have been subjected to various standard and non-standard, long-term and short-term, coupon and whole pipe tests. The results were compared to determine which tests could discriminate...
Author(s) : Rahman, Rahman 2006 Washington DC
Bell-and-spigot gasket-joint thermoplastic pipes such as Polyvinyl Chloride (PVC) are widely used in pressure applications for potable water distribution and transmission, and sewer force mains. The thrust forces which result at joints due to changes in the direction of flow or changes in the diameter size of a...
Author(s) : Hojer, Janson, Oderkerk, Venator 2006 Washington DC
For nearly three decades two technology processes have been available for production of PEX piping by moisture induced silane crosslinking (PEX-b). The first technology, the Sioplas™ process, was invented and patented by Dow Corning. This process requires extruding pipe from a reactive compound composed of silane...
Author(s) : Walker 2006 Washington DC
Arguably the greatest human needs and environmental challenges facing mankind involve water and sanitation. According to statistics gathered by the World Health Organization (WHO) and the United Nations (UN) about 1.2 billion people — one- fifth of the world population — lack safe drinking water and twice as many have...
Author(s) : Frimel 2006 Washington DC
For more than twenty years, CPVC compounds have been used to produce single-layer, allplastic tube and pipe for the Plumbing, Fire Sprinkler, and the Industrial Piping markets. Due to market changes, expansions, and the inherent limits to the single-layer product, a completely new, engineered piping system had to be...
Author(s) : Paschal, Hassinen 2006 Washington DC
With the implementation of NSF Protocol P171 in 1999, and subsequent adoption of ASTM F 2023 in 2000, Miner’s Rule has been used extensively in developing estimations of crosslinked polyethylene (PEX) pipe lifetimes when exposed to varying system conditions in the presence of chlorinated water. Previous work in this...
Author(s) : Shepherd, Headford, Jordan, Reeves, Walton 2006 Washington DC
In Europe polyethylene (PE) has been chosen almost exclusively for gas mains for many years because of economic, technical and safety reasons but in the water industry a number of different materials are still used for pressure water mains. Indeed at sizes above 355mm (14 inch) most new large diameter water mains are...
Author(s) : Boros, Mamoun 2006 Washington DC
In order to establish a Hydrostatic Design Basis (HDB) for PE materials according to ASTM D 2837, it is required to validate that the ductile/brittle transition is beyond 100,000 hours. This procedure uses elevated temperature hydrostatic stress testing to “validate” that the extrapolation of the ductile stress...
Author(s) : Bircumshaw, Orchard, Kenworthy, Stafford 2006 Washington DC
Funded by a UK government “SMART” award, the authors have explored the design options and practical solutions for installing large diameter multiple pipe ducts over very long distances. The work has involved consideration of the groundwork problems of microtunnelling or directional drilling at up to 1.5m (60ins)...
Author(s) : Pyo, Seo, Mutter, Broutman, Choi 2006 Washington DC
A novel Notched Ring Test (NRT) method for measuring slow crack growth (SCG) in plastics pipes and fittings is developed and applied to determine its applicability as the standard test method. NRT specimen in the form of a notched full ring, directly obtained from the extruded pipe or injection molded fitting...
Author(s) : Akiyama, Higuchi, Nose, Toyoda, Kitano, Kuriyama 2006 Washington DC
Since the year 2001, the Japan Gas Association has started the development of new renewal methods capable of cost reduction for modification work by inserting a new double-layered corrugated plastic pipe into the old gas pipe to encourage the modification of aged house pipes and upgrade the level of safety. The...
Author(s) : Fumire 2006 Washington DC
The level of gelation is a very important parameter in moulded PVC items since it will determine in a significant extent the mechanical properties of the item. Several methods have been developed already but none was widely used in processing plants except the Methylene Chloride test (MCT) which gives a pass/fail...
Author(s) : Castagnetti, Dragoni, Mammano, Fontani, Nuccini, Sartori 2006 Washington DC
The paper documents ongoing research aimed at determine the effect of disinfectants on high density polyethylene pipes (HDPE), commonly employed in modern urban networks for water conveyance. An experimental plant has been implemented, controlled by a PC, which monitors all the operating parameters. The experimental...
Author(s) : Ciechanowski 2006 Washington DC
Stress-rupture testing is generally performed on pipe and fitting compounds designed for pressure applications. Per PPI TR-2, the PVC resin in the compound formulation is required to have an inherent viscosity (IV) of 0.88 or greater and is sometimes referred to as ‘pipe grade’ resin. These compounds obtain a...
Author(s) : Sindelar, Nezbedova, Buran 2006 Washington DC
The influence of processing conditions on molecular structure and microstructure of highdensity polyethylene pipe material has been studied. By modifying the segment arrangement and package of additives, conditions during pelletising in the extruder have been changed. Structural analyses obtained by gel permeation...
Author(s) : Guldbaek 2006 Washington DC
In 2000 the Nordic Plastic Pipe Association (NPG) circulated a questionnaire to all Scandinavian municipalities (1000/252 replied) inquiring about the operating conditions of their sewer systems in plastics or concrete. Furthermore, a preliminary assessment had been carried out, summarizing the environmental effects...
Author(s) : Mason, Chen 2006 Washington DC
The small scale steady state (S4) test is a convenient and relatively inexpensive means of measuring the critical pressure (Pc) for rapid crack propagation in plastic pipes. The critical pressure measured in the S4 test is not the same as the critical pressure measured in a full scale test, which more directly...
Author(s) : Hsuan, Zhang, Wong 2006 Washington DC
The 100-year stress crack resistance (SCR) of corrugated HDPE pipes was evaluated using a 600 mm diameter pipe. The SCR tests were performed on the finished pipe at the liner and junction locations. The notched constant ligament stress (NCLS) test (ASTM 2163) was used for the pipe liner assessment. For the pipe...
Author(s) : Nishimura, Kawaguchi, Igawa 2006 Washington DC
This paper describes test methods for crosslinked polyethylene (PEX) pipes to evaluate long-term performance such as the resistance to chemical degradation due to residual chlorine at high temperature by the formation of crosslinked molecular structure and the addition of suitable antioxidants. As the methods of...
Author(s) : Vanspeybroeck 2006 Washington DC
Since 1997 electrofusion welders have been evaluated in Belgium on continuous basis. Parallel during this decade, traceability according to ISO 12176-4 : “Plastics pipes and fittings - Equipment for fusion jointing polyethylene systems - Part 4: Traceability coding” has been introduced by the Belgium gas...
Author(s) : Higuchi, Nakai, Hamada 2006 Washington DC
To realize a polyethylene pipe with high strength and a high modulus of elasticity, a polyethylene based composite pipe was tentatively fabricated. To retain the plasticity of the composite pipe, polyethylene yarns were used as reinforcement. It was an interface-less composite because the reinforcement and the pipe...
Author(s) : Kosari, Oliphant, Vibien, 2006 Washington DC
The Small Scale Steady State (S4) Rapid Crack Propagation (RCP) test methodology has proven to be an effective tool in assessing resistance to rapid crack propagation. At the same time, an evolution in polyethylene material performance has occurred that has produced materials with increasingly higher resistance to...
Author(s) : Bassewitz, Janson, Liebel 2006 Washington DC
From Jan 6th 2001 until March 31st 2005 a research project, funded by the German Ministry for Economy and Research had been carried out in order to investigate technical details not yet researched. The results of the project have shown that polymer flexible pipes for district heating are fit for purpose. The research...
Author(s) : Niebergall, Mertlova, Nezbedova 2006 Washington DC
Full Notch Creep Test (FNCT) is widely used to characterize the slow crack growth behavior of particularly pipe and blow moulding PE materials, especially in Europe. However, the validity of the FNCT data is not satisfactory, as the results show large variability so far. Among other SCG tests, which exist and are...
Author(s) : Striplin 2006 Washington DC
In the early days of polyethylene piping use, there was no forum, such as the Plastics Pipe Conference, where information could be disseminated and technical experience exchanged. Thus, each piping community, whether a pipe manufacturer, gas or water company, or technical body, developed their own philosophies and...
Author(s) : Michie, Chang, McNeil 2006 Washington DC
PE-100 pipe resins, through different molecular architecture, have significantly higher performance properties than traditional chrome (Cr) catalyzed products. Improvements in slow crack growth (SCG), rapid crack propagation (RCP) as well as excellent high temperature burst performance expand the performance...
Author(s) : Yoshikiyo, Hattori 2006 Washington DC
Polyethylene, especially PE100 Resin has been steadily increasing its use in pressure pipes for water and gas based on its superior property balance. Of all the properties required for PE100, when we consider the defects on the pipe surface and the stress concentrations on the fitting of complicated shape, the most...
Author(s) : Petroff 2006 Washington DC
Horizontal directional drilling (HDD) has given many municipalities and utilities the opportunity to utilize PE (PE) pipe in a more cost effective and efficient manner than traditional piping materials. A key feature of HDD is that it makes minimal impact on the environment and the community. This results in cost...
Author(s) : Lever, Palermo, Wright, Oliphant 2006 Washington DC
The piping industry has a need for a well-founded methodology to predict lifetime of pipeline components subject to stress concentration. Another useful tool would be a method to assess the impact of manufacturing processes on the slow crack growth (SCG) properties of a resin that can be used for process control in a...
Author(s) : McGoldrick, Baeckmann, Walton, Nestelberger 2006 Washington DC
Polyethylene has been in use for the manufacture of piping systems since the sixties and has progressed in its property spectrum not only in terms of resistance to pressure, but also both in terms of resistance to Rapid Crack Propagation and to Slow Crack Growth. In terms of processing friendliness however, further...
Author(s) : Schmaucks, Friede, Sorhuns, Roszinski 2006 Washington DC
For most pipe applications impact modification is not required. In certain cases however, in cold climates, for pressure or thin-walled pipes, high impact strength is essential. The general understanding of impact improvement of thermoplastics is that the presence of a second – elastomeric – phase is essential to...
Author(s) : Habedank, Haese 2006 Washington DC
M5000 - the largest methanol plant with a capacity of 640.000 t/a is being constructed with German support on Trinidad and Tobago. This plant is connected to existing ammonia plants. For the underground pipeline of 3,000 m the decision was taken in benefit of a polypropylene pipe, as it has low weight, good chemical...
Author(s) : Belforte, Gerard, Palermo, Guerra 2006 Washington DC
South America is a region with a fast increase in economic growth and energy needs, and natural gas represents a strategic energy source not only for producers like Argentina but also for net importers like Uruguay and source-differentiated countries like Brazil. The fast development of the economy leads to request of...
Author(s) : Hirase 2006 Washington DC
A new grade of PElOO has been successfully developed. The new grade has much higher flowability and much more attractive feature compared to the conventional PE100. The new grade is polymerized with a newly developed single site catalyst, which can precisely control the higher order structure as well as the molecular...
Author(s) : Jee, Buriak, Torres 2006 Washington DC
In a pipe manufacturing process, extrusion parameters are optimized to assure the maximum production of quality pipe meeting appropriate standard requirements. As equipment technology has evolved, the use of grooved feed extruders has created a significant improvement in the ability of extruders to manufacture quality...
Author(s) : Colin, Audouin, Verdu, Rozental-Evesque, Matin, Bourgine 2006 Washington DC
This article deals with the kinetic modelling of reactions between chlorine dioxide used as disinfectant and components of stabilized polyethylene pipes used for the transport of drinking water. From the study of antioxidant thickness distribution after accelerated aging (20 or 40°C, high concentrations of chlorine...
Author(s) : Vestman, Andtbacka, Groen 2006 Washington DC
The ability of a solid wall PE pipe (or solid wall pipe of any other material) to support internal pressure is directly related to the pipe’s ‘diameter to wall thickness’ ratio, the DR (dimension ratio) of the pipe. Pipe of a given material type with the same DR, regardless of size, have the same internal pressure...
Author(s) : Chang, Zhou, Michie 2006 Washington DC
MTD Pipeline LLC is a joint venture between Martin Marietta Magnesia Specialties LLC and The Dow Chemical Company. A nearly 30 miles of high density polyethylene (HDPE) pipeline project in northern Michigan is serving as the latest example of technology evolution for polyethylene (PE) pipe used in underground pipe...
Author(s) : Farshad 2006 Washington DC
This contribution deals with the short-term and the long-term behavior of multi-layer pipes subjected to internal hydrostatic pressure. A new methodology for prediction of long-term behavior of multi-layer pipes under internal hydrostatic pressure taking into account the material differences and the composite pipe...
Author(s) : Houle 2006 Washington DC
Molecularly oriented polyvinyl chloride pipe (PVCO) was developed in Europe in the 1970’s but was not commercialized in North America until the early 1990’s. This paper briefly examines the current state of the North American oriented pipe market and discusses molecular orientation and its effects. A brief history of...
Author(s) : Kratochvilla, Muschik, Dragam 2006 Washington DC
Slow crack growth (SCG) was measured by means of an adaptive to the Full Notch Creep Test (FNCT) : the 2-Notch Creep Test (2NCT). This notching geometry offers the advantage, that the sensitive zones of samples made of pipe specimens are conserved : the inner- and outer-pipe wall layers. This test geometry makes it...
Author(s) : Spaeth 2006 Washington DC
Polyethylene is a modern, environmentally compatible material that displays major potential for the substitution of conventional pipe materials. In the field of underground pipelines, polyethylene has unequivocally asserted itself as the material of choice for pressurised pipe systems. The polyethylene pipe in...
Author(s) : Godon, Bettonville 2006 Washington DC
PE Pipe materials have always been a compromise between a set of requirements. On top of the expectation from pipe makers to have a good processability, end users would expect for the guaranteed long life of pipes made of PE a minimum requirement on • Stiffness, yield strength, hydrostatic strength or Minimum Required...
Author(s) : Bar, Nitz 2006 Washington DC
PEX (cross-linked Polyethylene) pipes have been traditionally used for indoor applications such as underfloor heating, hot and cold water pipelines and district heating pipelines. Recently these pipes are being used in mainly industrial applications, water mains and gas lines. The success of PEX pipes in these and...
Author(s) : Palermo, Vibien, Oliphant, Kosari 2006 Washington DC
The corrugated HDPE pipe industry is considering the responsible use of recycled materials in their pipe production and also in their pipe standards. One of the key requirements for successful use of recycled materials is ensuring performance of the resulting HDPE corrugated pipe. As slow crack growth (SCG) has been...
Author(s) : Scholten, Shin 2006 Washington DC
Ultrasonic detection equipment was used to investigate defective pipes and fusion joints. The following examples of its application are presented. Electro-fused joints were tested in four different 110mm PE100 and PEX pipes. The PEX pipes showed a less complete fusion between pipe and fitting in comparison to PE100...
Author(s) : Lowe, Starkey, Powell 2006 Washington DC
With the increasing success of PE100 and usage of pipes of increasingly large diameter, concerns have been raised about the quality of weld performance with relatively thick walled pipes (>50mm), which has led to the current investigation. In addition to the consideration of welding conditions adopted in the UK,...
Author(s) : Adams, Huska, Reinicker 2006 Washington DC
Heavy metal colorants have long been used in plastics applications for the simple reasons that they are heat stable and durable. In the coloration of polyethylene for weatherable applications, for example, the cadmium and lead chromate yellows have had a substantial market. With environmental concerns of the last...
Author(s) : Steve D. Sandstrum, White G. Jee 2006 Washington DC
Polyethylene pipe produced from resins meeting the criteria for the PE 100 designation were first introduced on an international scale in the late 1980’s. Since, that time these piping products have grown to become recognized as the international standard for longterm performance in the use of polyethylene pipe. The...
Author(s) : Rugraff 2006 Washington DC
Sustainable development is a widely used (and sometimes misused) terminology, which brings together two concepts : “satisfaction of present needs” and “possible satisfaction of future needs”. Life cycle analysis for PE pipes are available regarding the energy content of the pipes and their aptitude for energy...
Author(s) : Schramm, Jeruzal 2006 Washington DC
The development of a new family of PE materials with significantly improved processability and long-term strength at high temperatures is discussed. These polymers form the basis for a new ISO class of polyethylene materials : PE-RT (Polyethylene of Raised Temperature resistance) for hot and cold water as well as...
Author(s) : Zhou, Chang 2006 Washington DC
High density polyethylene (HDPE) pressure pipe may be scratched during installation. The scratches reduce the wall thickness and therefore increase the dimension ratio (SDR pipe). 1” SDR 11 pipe samples extruded from bimodal PE100/PE4710 and unimodal PE80/PE3408 pipe materials were used to investigate the effect of...
Author(s) : Meijering 2006 Washington DC
The possible effects of plastics pipes on drinking water quality are frequently in discussion and require the highest attention of our industry. On one hand, the European Commission (EC) is working already long time to set up a European Acceptance Scheme (EAS), so far without the desired speed. The Plastic Pipe...
Author(s) : Eckert 2006 Washington DC
The use of plastic pipes has to date been limited to operating pressures of max 10 bar / 145 psi for gas supply and 16 bar / 230 psi (25bar / 360 psi) for water supply. Polyamide – the new high-performance material for gas pipes - and multi layer pipes with integrated reinforcement allows operating pressures to be...
Author(s) : Wroblewska, Drzewiecki, Kwietniewski 2006 Washington DC
The last fifteen years have brought to Poland significant political and economic changes. The accession to the European Union appeared the biggest challenge due to the need to adjust Poland to higher European standards in law, agriculture, education, finance etc. One of the most financially neglected areas, where the...
Author(s) : Lohmar, Baron, Dowe, Wessing 2006 Washington DC
PA 12 is a high performance polymer with outstanding mechanical properties and excellent chemical stability. It is the preferred material in many demanding applications, e. g. in the automotive industry for fuel lines of passenger cars or for air brake tubing in trucks. Compared with polyethylene (HDPE) it has a...
Author(s) : Gard, Stamm, Schmidt 2006 Washington DC
Plastics materials are rapidly replacing copper pipes and fittings in domestic plumbing and heating systems throughout the world. Over the last 20 years pressure pipe systems made from Polypropylene Random Copolymers (PP-R) have been widely adopted by the plumbing and heating industry in numerous countries around the...
Author(s) : Chapman, Macovaz 2006 Washington DC
Material efficiency is a focal point for the thermoplastic pipe industry. With the high embodied energy content of the materials, the environmental and cost gains to be made through material savings are significant. Many techniques have been developed for the manufacture of both pressure and non-pressure pipe to...
Author(s) : Catanzano, Bosetti, Walton, Serrao 2006 Washington DC
The development of gas, water and sewerage networks greatly enhanced city life in the late 19th and early 20th Century providing much needed street lighting and dramatically reducing water borne disease. Understandably in many European cities these underground piping systems are now showing serious signs of their...
Author(s) : Creelman, Fisher, Franzen 2006 Washington DC
Two recycling case studies are presented. The first is the program at Royal Pipe Systems’ plant in Abbotsford, BC. Royal Pipe Systems works with the City of Abbotsford and Marv’s Excavating to collect post-industrial vinyl and reconverts it back into PVC pipe. The second is the program at Specified Fittings’ facility...
Author(s) : Rahman, Bird 2006 Washington DC
The jointing of municipal Polyvinyl Chloride (PVC) pipelines in North America and in many countries around the world is achieved by means of a rubber sealing ring seated in the pipe bell to effectively prevent leakage between two adjoining pieces of pipe after the spigot (male end) is inserted into the bell (female...
Author(s) : Haager, Pinter, Lang 2006 Washington DC
It is well known that resistance against slow crack growth is important for the lifetime of pressurized polyethylene (PE) pipes. Thus several methods have been proposed to evaluate the long-term performance of PE using fracture mechanics. It is generally believed that this leads to results more quickly compared to...
Author(s) : Krishnaswamy, Leevers, Lamborn, Sukhadia, Register, Maeger 2006 Washington DC
The influence of molecular architecture on the rapid crack propagation (RCP) resistance of a wide variety of high-density polyethylene (HDPE) pipes was investigated. It was concluded that high molecular weight, high crystallinity and a relatively narrow molecular weight distribution are important architectural...
Author(s) : Leevers, Henderson, Pereira 2006 Washington DC
Laboratory-scale S4 tests have been used to determine whether it would be possible, at any realistic working pressure, for a loosely-fitted PE liner within a rigid host pipe to fail by Rapid Crack Propagation (RCP). The standard ISO 13477 S4 method was modified by replacement of the containment ring cage by a rigid,...
Author(s) : Wroblewska, Roszkowski 2006 Washington DC
The development of gas networks and the significant increase of the number of gas consumers in Poland has resulted in making many strategic decisions connected with investment process in this sector. At the same time, better and more technologically advanced materials applied in gas pipeline constructions and their...
Author(s) : Becker, Shepherd 2006 Washington DC
In common with most other major cities around the world, London has grown outwards from the centre as its population has increased. What may not be appreciated is that this holds true not only for the roads and buildings but also for the buried infrastructure, particularly the water mains and sewers, which were the...
Author(s) : Tominaga, Akiyama 2006 Washington DC
Gas utilities are required to accurately understand the lifetime characteristics of gas polyethylene (PE) pipe in detail. Understanding the effects of varying temperature conditions is one of our goals, because the actual environmental temperature of PE gas pipe is not constant but varies. This is particularly true...
Author(s) : Maeger, Vanspeybroeck, Lamborn, Mamoun, Leevers, Oliphant 2006 Washington DC
As polyethylene pressure pipes enter the global marketplace under an ever-wider range of operating conditions, there is increasing emphasis on their rapid crack propagation performance. It is important that both producers and end-users are able to rely on the robustness of the rapid crack propagation test results and...
Author(s) : Wood, Richards, Street, Muckle, Bowman 2006 Washington DC
For the movement of fuel gas and water, plastics pipes are dominant in many markets, and this success has been based on single material solid wall pipes. There are now an expanding number of multi-layered plastics pipes, and described here for the first time is the performance of the second-generation of skinned pipe...
Author(s) : Tabanelli 2006 Washington DC
In polyethylene piping systems for conveying pressurised water the use of socket systems for pipe joining is relatively uncommon. This is because the significant thickness of the pipe walls makes the system for thermoforming of the socket at the pipe end complex and economically unattractive. Only recently...
Author(s) : MacKellar, Lowe, Ingham, Ashdown 2006 Washington DC
Polyethylene (PE) is the preferred material for 90% of all water mains laid in the UK. The pace of renovation of dilapidated cast iron water networks has led to the increasing demand for coils of flexible PE pipe, driven by the efficiency of using less joints and taking up considerably less space in the congested...
Author(s) : Lauder 2006 Washington DC
If you were to visit a PSE&G gas main installation site today, where a large diameter cast iron main replacement project is underway, you would see a very familiar scene but with one important difference. Typical of any such project, you would see heavy equipment, trench excavations and traffic control, but...
Author(s) : Meijering 2006 Washington DC
Teppfa and Plastics Europe initiated a comprehensive study to provide quantitative figures of the quality of sewers after long life service of up to 30 years. The overall aim and purpose of the project was to determine which sewer pipe materials better fulfil the requirements of sustainability in its broadest sense,...
Author(s) : Fiedler, Ebner 2006 Washington DC
In the past, rigid pipes made of conventional materials such as vitrified clay, concrete or cast iron were the preferred materials for sewage pipe works in many countries in Europe like in Germany due to their wide availability and their familiarity to the end-user. Such pipes do not fulfill the increasingly rising...
Author(s) : Campbell 2006 Washington DC
The primary reason for the regulation of the flammability of building materials is for the safety of the occupants of buildings and other structures. Building codes regulate the type of materials, their use and combustibility in all types of buildings. All jurisdictions have various versions of a building code, which...
Author(s) : Reinking, Mehta, Garrison, Joseph, Schwab 2006 Washington DC
Bimodal polyethylene (PE) pipe resins have demonstrated a step change in slow crack growth (SCG) and rapid crack propagation (RCP) resistance over conventional unimodal polyethylene resins. Literature shows that homopolymer polyethylene has higher RCP resistance than PE copolymers, which suggests a trade-off between...
Author(s) : Osry, Tjabring 2006 Washington DC
International developments, increased demand and environmental concerns have led to the increasing need for energy efficiency and conservation. The energy crisis relates directly to the more effective use of natural resources and reduction in the emission of greenhouse gases. This paper discusses actions the plastics...
Author(s) : Bird, Caravaca, Raude 2006 Washington DC
Electrofusion joints for polyethylene pipe are one of the common joining methods used in the water and gas industries for distribution pipelines. Common problems in manufacture of these joints are contamination, lack of fusion, lack of penetration and insufficient heat applied to the joint. The latter flaws can result...
Author(s) : Howard 2006 Washington DC
The Reclamation table of E′ (Modulus of Soil Reaction) values for use in estimating the deflection of buried flexible pipe was first published in 1977. The E′ value represents the stiffness of the embedment soil placed on the sides of the pipe. The table gave E′ values that depended on soil classification and...
Author(s) : Crepin-Leblond 2006 Washington DC
Talc is widely used to reinforce plastic resin. End use applications range from automotive, packaging, wood plastic composites, nucleation, anti-blocking to foamed structure as well as pipes. The paper given by Rio Tinto Minerals- Luzenac will focus on plastics pipes applications where talc is a cost-effective...
Author(s) : Klopffer, Flaconneche 2006 Washington DC
In the oil and gas industry, polymer materials are used for their excellent barrier properties and their main function is to ensure leakproofness. Moreover, these semicrystalline polymers are exposed to different gases (alone or in a mixture) under extreme conditions of temperature and pressure (up to 130°C and up to...
Author(s) : MacKellar 2006 Washington DC
In 2002 UK Water Industry Research Ltd commissioned Bodycote PDL to collate and maintain a database of all water main failures in the UK and develop a protocol for data collection of failure information. Despite the huge disparity in the data formats from each company this has been achieved and maintenance of the...
Author(s) : Weiher, Zilch 2006 Washington DC
HDPE is used in bridge construction as part of the corrosion protection system of steel tendons in post-tensioned bridges. There are different types of HDPE sheathings that vary in thickness, number of layers and shape. Within this article these products and their applications will be presented. Furthermore, all the...
Author(s) : Palermo 2006 Washington DC
The CRS (Categorized Required Strength) concept was developed within the ISO pressure rating system to provide more flexibility to the design engineer. One of the major uses of CRS is to provide a design basis of 100 years for plastic piping applications. With the CRS concept plastic pipe can now have a design basis...
Author(s) : Ariaratnam 2006 Washington DC
Trenchless construction techniques have gained popularity over the past decade for the installation of underground utility systems. The choice of appropriate pipe material has been often a challenge for engineers and designers of such projects. While the gas industry has adopted polyethylene pipe for years, some...
Author(s) : Tabanelli 2006 Washington DC
Given the same operational pressure, the required thickness of molecularly oriented PVC pipes is 35-40% less than for PVC-U pipes. This is one of the various advantages of the material, which is interesting an increasing number of producers. The technical and commercial success of PVC-O pressure pipes relies heavily...
Author(s) : Nitz, Vogt 2006 Washington DC
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