The Evolution of Elastomeric Joints in Plastic Pipeline Systems

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...

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...

Author(s) : Mario Messiha, Andreas Frank, Isabelle J. Berger, Jan Heimink, Hermann van Laak, Florian Arbeiter, Gerald Pinter

Since the last decade polyamide 12 (PA12) has been successfully introduced as material for SDR 11 gas piping systems up to 18 bar, representing itself as an attractive alternative to steel pipes for high-pressure applications. Practical experience has confirmed that beside the higher strength, PA12 pipe grades also...

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...

Author(s) : Carlos Domínguez, Álvaro Pérez, Nuria Robledo, Cristina González, Beatriz Paredes, Rafael A. García-Muñoz

Last methodologies for fast evaluation of the SCG resistance on polyethylene pipe materials are analyzed in this work and compared with traditional PENT and FNCT tests. Strain Hardening (SH), Crack Round Bar (CRB) and Accelerated Creep Test (ACT) will be good alternatives for evaluating PE100RC resins. Moreover, SH...

Author(s) : Mitsuaki TOKIYOSHI, Gentaro TAKAHARA, Joji HINOBAYASHI, Toshinori KAWABATA, Takashi KURIYAMA

Glass fiber reinforced polyethylene pipes and fittings are controlled for bending characteristics (Strength and stiffness) for vertical and axial directions of pipe by spiral cross winding method. Generally, to use this method, it takes much stronger for vertical strength than axials cause of extruded direction,...

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...

Author(s) : Sverre Tragethon, Martin Andersson

Global mega trends push for investments in sewage treatment capacity & efficiency. A trend is to go for central regional treatment sites, typically remotely located from dense populated cities. This calls for high capacity pressure sewage transmission pipelines. Reliable operation is of course of paramount importance...

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...

Author(s) : Peter Verlaan

Ten years ago, The European Plastic Pipes and Fittings Association (TEPPFA) has taken the initiative to prepare a draft 'Standard for Infiltration units' based on existing national specifications, at that time (in particular) available in France, Germany, United Kingdom and the Netherlands. This draft 'Standard for...

Author(s) : Dr. Love Pallon, Dr. Karin Jacobsson, Daniel Ejdeholm, Marie Allvar, Rikard Kärrbrant

This work presents the development of the Full Length Tensile Test (FLTT), a method that enables an objective judgement of welding quality of electrofusion welds by measuring the energy to break (J/mm2 ). In this way a brittle, ductile and transitional mode failure can be differentiated without subjective visual...

Author(s) : Hirofumi Kyutoku, Kazuhisa Igawa, Hidekazu Honma, Sakiko Fukunishi, Hiroyuki Nishimura

There are mainly two grades of polyethylene pipes for hot water supply and heating. The excellent molecular structure polyethylene resins having resistance to stress crack growth are used because hot water is flowed for a long time in both polyethylene pipes. Furthermore, various additives are mixed to prevent the...

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...

Author(s) : E.J.W. van der Stok

The effect of eleven different test parameters on the strain hardening modulus was investigated using the Design of Experiments statistical method. The changes in strain hardening modulus due to temperature, tensile drawing speed and the cooling rate after annealing were assessed. The importance of taking account of...

Author(s) : Julian West

Until the late 1950’s, water and sewerage pipe lines used predominantly rigid joints. These were often made from tarred rope and cement mortar. The introduction of ‘flexible’ elastomeric joints allowed angular deflection, transverse shear load and localized pipe deformation without leakage or failure of the joint....

Author(s) : André Nijland

Bi-oriented PVC (PVC-O) pipes are increasingly installed on a worldwide basis for drinking water applications. This is due to the outstanding mechanical properties of PVC-O pipes, such as high strength and high ductility. Furthermore bi-oriented PVC pipes are light weight, flexible and have a low carbon footprint and...

Author(s) : Takehiro Fujii, Kazuhisa Igawa, Hidekazu Honma, Kazushi Yamada, Hiroyuki Nishimura

The hydrostatic stress rupture test has been conventionally conducted as a good method of the lifetime evaluation. The hot water circulation test which is reflected to the actual operating condition is also useful method. The correlations and differences between the two tests were examined. Compared with the...

Author(s) : Jim Goddard, Mario Paredes

Samples of polyethylene pipe supplied to mining projects throughout the Americas were selected and tested for compliance with existing ASTM specifications. Estimated service life of these pipe products in mining applications are made based on the laboratory tests required in the ASTM specifications. Anticipated...

Author(s) : Ernst van der Stok, Frans Scholten

Samples machined directly from pipe show that orientation has a large influence on the strain hardening modulus. No effects arising as a result of residual stresses were found. Samples machined in the axial direction from a hydrostatic pressurised pipe showed no effect as a result of this mechanical degradation. For...

Author(s) : Yuji Higuchi, Rei Hyuga, Kazushi Yamada, Hiroyuki Nishimura

Recently, thermoplastic-based composite pipes have been developed in order to satisfy the higher requirements for gas and water distribution. Although the stress rupture test is now the major test method used to evaluate the long-term performance of these pipes, developing a new, convenient test method making it...