Acceptance criteria for non-destructive testing of PE electrofusion joints

 

Papers # 2016 Berlin

On request of the Dutch DSO’s and in cooperation with all important Dutch stakeholders (producers, suppliers, contractors and the regulator), Kiwa Technology investigated the relevancy of defects found with Phased Array Ultrasonic Testing (PAUT) and if it was possible to determine acceptance criteria. The project showed that using the PAUT nondestructive testing (NDT) method, mainly voids are found, and that there is a relationship between presence of voids and destructive test results. Based on the results, preliminary acceptance criteria are proposed.

On request of the Dutch DSO’s and in cooperation with all important Dutch stakeholders (producers, suppliers, contractors and the regulator), Kiwa Technology investigated the relevancy of defects found with Phased Array Ultrasonic Testing (PAUT). The objective was twofold:

  • Can relevant defects, that occur in practice, be found with PAUT?
  • Is it possible to setup acceptance criteria?

The project showed that with PAUT mainly voids are found in electrofusion joints made in practice. It was not possible to detect so called cold welds (brittle failure) directly. Still, there is a relationship between the presence of deviations and brittle failure in a peel decohesion test (ISO 13954 [1]). Based on these results, the stakeholders agreed on preliminary acceptance criteria.

Related keywords : Electrofusion joint, non-destructive testing, PAUT.
Please note that the whole article content is available on PPCA website onlySource : 2016 Berlin


Related papers

A new flexible jointing method of plastic (PE) pipes

Author(s) : Yilaing He, Tianjun Zhang 2018 Las-Vegas

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...

Acceptance criteria for volume defects in welded assemblies, detected and sized using the phased array ultrasonic technique

Author(s) : Dominique GUEUGNAUT, Manuel TESSIER, Romuald BOUAFFRE 2018 Las-Vegas

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...

Development of cyclic pressure fatigue (CPF) test method

Author(s) : Ernest Lever 2018 Las-Vegas

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...

Development of large-diameter continuous-fiber - Reinforced thermoplastic pipe

Author(s) : Fengliang Jiang, Nian Wu 2018 Las-Vegas

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...

Innovative millimeter waves technology for measuring diameter, ovality, wall thickness, and sagging of large plastic pipes

Author(s) : Christian Schalich 2018 Las-Vegas

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...

Modern PE pipe enables the transport of hydrogen

Author(s) : R.J.M. Hermkens, H. Colmer, H.A. Ophoff 2018 Las-Vegas

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...

New testing method for electrofusion welds

Author(s) : Dr. Love Pallon, Dr. Karin Jacobsson, Daniel Ejdeholm, Marie Allvar, Rikard Kärrbrant 2018 Las-Vegas

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...

PE100-RC in large diameter sea outfall applications

Author(s) : Mark Yu, Dongyu Fang, Peck Tze Kang, Amos Tay , Fan Liu 2018 Las-Vegas

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...

Preserving marine environment from hydrocarbons contamination with leak-free PE100 pipes used in off-shore oil wells

Author(s) : Farraj Tashman, Mohamed Ali Jaber, Sultan Al Kendi 2018 Las-Vegas

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...

Quality assurance on welded joints with the mechanised linear shear test (lst)

Author(s) : Juergen Wuest, Benjamin Baudrit, Frank Dorbath, Christopher Pommer 2018 Las-Vegas

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...

Slow crack growth resistance of non-virgin polymers

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 2018 Las-Vegas

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...

Big data, big difference

Author(s) : Nick Mark, Eric Bridgstock, David Carey 2016 Berlin

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...

Development of flaw acceptance criteria for welded joints in PE pipes

Author(s) : Mike Troughton, Amir Khamsehnezhad 2016 Berlin

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...

Digital radiography of PE joints

Author(s) : Mats Bergman, Karin Jacobson 2016 Berlin

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...

Electrofusion joining performance of very large pressure pipes produced with MFR5<0.2 g/10min PE100

Author(s) : Predrag Micic, Cliff Mure 2016 Berlin

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...

Lifetime prediction of PE100 and PE100-rc pipes based on slow crack growth resistance

Author(s) : Andreas Frank, Isabelle J. Berger, Florian Arbeiter, Pavel Hutař, Gerald Pinter 2016 Berlin

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....

Long term influence of defects in butt fusion joints on PE100 pipes and NDT detection of them

Author(s) : Jörg Wermelinger, Oliver Hein 2016 Berlin

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...

Potentials of terahertz technology for the inspection of plastic pipes

Author(s) : Stefan Kremling, Thomas Hochrein, Peter Heidemeyer 2016 Berlin

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,...

Quality control testing of joints in gravity flow plastic pipes

Author(s) : David Becerril García, Jacinto Cortés-Pérez, Ian D. Moore 2016 Berlin

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...

Research program for assessing seismic risks on polyethylene gas pipelines

Author(s) : Dominique GUEUGNAUT, Charles FERNANDEZ, Romuald BOUAFFRE, Bertrand SEVRE, Florent ANGELINI 2016 Berlin

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...

Members of the Association

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