Acceptance criteria for non-destructive testing of PE electrofusion joints

Author(s) : Yilaing He, Tianjun Zhang

A new electrofusion PE belt is developed by reinforcing it with various layers of steel mesh. It’s of sandwich structure, consisting of steel mesh reinforcement, heating wire and polyethylene. One or more layers of steel mesh is encapsulated in the middle, and heating wire is embedded onto “inner side” of the belt....

Author(s) : Dominique GUEUGNAUT, Manuel TESSIER, Romuald BOUAFFRE

Given the virtual absence of available up-to-date results regarding the acceptance criteria for defects at electro-welding interfaces, a study has been launched by GRTgaz RICE with the two-fold aim of confirming the accuracy of the PAUT technique for the detection and sizing of calibrated pit-shaped defects implanted...

Author(s) : Ernest Lever

Six different polyethylene materials were tested using Cyclic Pressure Fatigue (CPF) as the accelerating process to correlate the results to conventional long-term hydrostatic test results that were previously developed as part of the material qualification process. The designation of the materials was unknown to the...

Author(s) : Fengliang Jiang, Nian Wu

This article discusses the development of the technique in producing large-diameter, medium-and-lowpressure water-delivery pipes. The continuous fiber-reinforced thermoplastic tapes perfectlyimpregnated with thermoplastic resin are wound layer by layer to form three-layer fibre reinforced polyethylene(PE) composite...

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...

Author(s) : R.J.M. Hermkens, H. Colmer, H.A. Ophoff

To investigate the suitability of PE pipes for the transport of hydrogen on a specific industrial site, three topics were investigated. These topics are: the chemical resistance of PE to hydrogen, the permeation rate of hydrogen through PE and the electrofusion of PE pipes exposed to hydrogen. It can be concluded that...

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) : Mark Yu, Dongyu Fang, Peck Tze Kang, Amos Tay , Fan Liu

Large diameter pipe was introduced in refineries and petrochemical plant, desalination plant and power plant for water intake and sea out fall in the past decade. PE100-RC material was selectedfor its excellent balance of superior bi-modal stress crack resistance and consistent high stiffness modulus. Under the...

Author(s) : Farraj Tashman, Mohamed Ali Jaber, Sultan Al Kendi

Analysis of subsea PE100 pipeline conveying oil produced water effluent with traces of hydrocarbons was done after 5 years of leak-tight continuous operation at boundary conditions showed that properties of PE100 pipes are intact when benchmarked with test results conducted on reference pipe sample kept for this...

Author(s) : Juergen Wuest, Benjamin Baudrit, Frank Dorbath, Christopher Pommer

A testing apparatus for determining the mechanical properties of electrofusion and heated tool sleeve welded joints with the mechanized linear shear test (LST) was developed. The LST-apparatus allows the recording of the force as a function of the extension / shear length. It has been proved that the linear shear test...

Author(s) : Andreas Frank, Isabelle J. Berger, Mario Messiha, Carl-Gustaf Ek, Norbert Schuler, Jens-Martin Storheil, Erwin Mayrbäurl, Steve Heeley, Frank Krause, Lodewijk Niemöller, Philippe Gabriëls, Yogesh S. Deshmukh, Florian Arbeiter, Thomas Koch, Gerald Pinter

In order to improve the circular economy of polymers in terms of sustainability and reduced carbon footprint, the increased use of recyclates has become a topic of major importance. Due to their long design lifetimes, pipe applications represent an excellent opportunity to create added value to non-virgin polymers. In...

Author(s) : Nick Mark, Eric Bridgstock, David Carey

An insight into a unique approach to the management of electrofusion and butt fusion joint quality on polyethylene pipelines. The presentation will reference experience and learnings from a system that has already been used in the field to great effect (see Abstract) and a new approach to butt fusion (see enclosed...

Author(s) : Mike Troughton, Amir Khamsehnezhad

the inspection of butt fusion and electrofusion joints in polyethylene (PE) pipes. Depending on the technique and inspection procedure, various types of flaw, including discrete planar lack of fusion, particulate contamination, voids, cold fusions and pipe under-penetration can be detected. However, the usefulness of...

Author(s) : Mats Bergman, Karin Jacobson

The Swedish Water & Wastewater Association (SWWA) has funded a R&D project to investigate different methods suitable for installation inspection of PE joints in field. Methods like phased array ultrasonic testing (PAUT), microwave technology and digital radiography were studied. Digital radiography shows promising...

Author(s) : Predrag Micic, Cliff Mure

An extensive investigation was conducted into the electrofusion compatibility of pipes produced using a PE100 resin with an MFR5 value below 0.2 g/10min. The electrofusion (EF) joining program included pipes up to 800 mm in diameter and the use of electrofusion couplers and saddle type fittings as well as varying...

Author(s) : Andreas Frank, Isabelle J. Berger, Florian Arbeiter, Pavel Hutař, Gerald Pinter

Due to the high slow crack growth resistance of modern polyethylene pipe grades a reliable lifetime assessment of pipes with focus on stage II failure has become challenging. The current paper presents a scientific approach for a fracture mechanics lifetime prediction based on Cyclic Cracked Round Bar (CRB) Tests....

Author(s) : Jörg Wermelinger, Oliver Hein

More and more a strong desire is noticeable for Non Destructive Testing (NDT) of welded PEjoints. The objective is to determine the long term performance of plastic piping systems made from PE100. To assess the impact of “mostly known defects“ on the long term performance of a welding, well-defined flaws have to be...

Author(s) : Stefan Kremling, Thomas Hochrein, Peter Heidemeyer

In plastics industry, the use of terahertz technology opens up opportunities for novel non-destructive and contactless testing applications. For example, the thickness of individual layers of a foamed multilayered plastic pipe can be monitored contactless and continuously during the extrusion process. Furthermore,...

Author(s) : David Becerril García, Jacinto Cortés-Pérez, Ian D. Moore

Joint performance of joints in gravity flow buried pipelines is very important since joint failure could produce structural or service limits to the system. Standards have been developed to evaluate that joints have the necessary structural and leakage capacities which specify test methods that are not clear and do...

Author(s) : Dominique GUEUGNAUT, Charles FERNANDEZ, Romuald BOUAFFRE, Bertrand SEVRE, Florent ANGELINI

Representative earthquake loadings have been reproduced in the ENGIE Lab-CRIGEN laboratories on three PE grades, including an excavated old PE63 pipe operated during more than 35 years. Dynamic loading does not alter the pipe residual performances for the three PE families tested, as shown by both the hydrostatic...