A More Reliable Detergent for Cone and Full Notch Creep Testing of PE Pipe Materials [PE]

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) : Dominique GUEUGNAUT, Adil BOUJLAL, Aymeric LOPITAUX, Bertrand SEVRE

A special concept has been developed by GRTgaz Research and Innovation Center for Energy (RICE) for temperature mapping at the interface of an electrowelded assembly.The technical solution consists of a tubular piece in place of the real PE pipe, made of a non-weldable polymer with thermal parameters close to those of...

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) : Frans Scholten, Ernst van der Stok

The residual quality of first generation PE50 gas pipes, installed in Netherland between 1961 and 1979, is still remarkably good. The only premature failures of a few PE50 pipes were exclusively caused by point loads. When under point loading, they started failing in practice after 8 to 26 years, in a brittle manner....

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...

Author(s) : Frans Scholten, Ernst van der Stok, Britta Gerets, Mirko Wenzel, Mike Boege

The current condition of 35-50 years old uPVC main (110 mm) and service (32 mm) pipes for gas and water distribution was assessed. From 27 excavation sites in total about 400 segments of 1.2 meters length each were tested using many techniques. The K-value (average molecular weight) of the PVC, the degree of gelation...

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

This paper describes falling-weight tests as a first step towards determining the effect of residual stresses on the fracture behaviour of old PVC-U gas pipes at impact. Results showed that the level of surrounding pipe support, the quality of the material and the diameter of the striker had a major effect on the...

Author(s) : Dominique GUEUGNAUT, Adil BOUJLAL, Aymeric LOPITAUX, Romuald BOUAFFRE

A specific methodology has been designed by ENGIE’ R&T Division to allow an accurate determination of the initiation (incubation) time of the NCBT data. This methodology is based on two different data processing procedures. The first data processing proceeds from searching the minimum of the second derivative of both...

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

A test campaign has been carried out by ENGIE Lab-CRIGEN in order to evaluate the acuity of the Phased Array Ultrasonic Technique (PAUT) for detecting and sizing calibrated defects implanted at the inner surface of a PE pipe.These calibrated defectshad four different geometries, called “V-shaped”, “half-V shaped “,...

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

Very occasionally PVC-U water pipes suddenly fail due to a long brittle crack with a length of many meters which propagates with the speed of sound along the pipe and causes extensive water loss. This phenomenon has been recognized as Rapid Crack Propagation (RCP). The conditions under which RCP can occur are an...

Author(s) : Frans Scholten

When electro fused joints in newly installed PE100 pipelines are tested using the Peel test (ISO 13954 [1]) they too often fail in a brittle manner. Contamination in the interface between the surfaces to be fused is usually the cause. About 77 % of the contaminants in 39 cases of brittle test bars could be identified...

Author(s) : GUEUGNAUT Dominique, BOUJLAL Adil, BOUAFFRE Romuald, LOPITAUX Aymeric

The emergence of a new generation of PE100, named PE100 RC, with a significant enhanced Slow Crack Growth (SCG) resistance enlights the need for new testing methods in order to be able to test such resins in reasonable test durations. Consequently in the last five years some new tests have been designed to assess for...

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

The Strain Hardening (SH) test and the Point Load Test (PLT) are two complementary tests designed to determine the quality of PE 100-RC. The SH test is a resin test, whereas the PLT is a pipe test. The SH test is a tensile test performed at 80 °C. Extensive research on the SH test has been conducted and published in...

Author(s) : GUEUGNAUT Dominique, ANGELINI Florent, BOUJLAL Adil, BOUAFFRE Romuald, SEVRE Bertrand, LOUET Patrick

Polyethylene (PE) is a widespread material for the manufacturing of gas and water distribution pipelines and a large number of PE electrofusion pipe joints can be found over the thousands of kilometres of PE pipeplines all over the world, thus generating an increasing interest in checking the quality of these joints....

Author(s) : Chebbo Z., Boujlal A., Gueugnaut D., Vincent M., Tillier Y.

(Electrofusion, Finite Element, Heat transfer, Interdiffusion, crystallisation and melting Kinetics, Micro-sampling) Electrofusion (EF) is widely used to join polyethylene (PE) components in the gas distribution networks. This paper provides experimental and 3D-finite element tool capable of reproducing the major...

Author(s) : Gueugnaut Dominique, Boujlal Adil, Rousselot Denise, Bouaffre Romuald

(Polyethylene, SIS technique,Micro-sampling)The use of polyethylene(PE) since the early seventies on the GDF SUEZ’ distribution networks has lead to the coexistence of a very wide variety of PE resinswith significant differences in their long term performances. Nevertheless, in order tojustify a possible delayed or...

Author(s) : Van der Stok, Scholten

The Strain Hardening (SH) test developed by Kurelec et al. has been applied to a variety of PE pipe and resin materials. The clear trend in the strain hardening modulus, of first, second and third generation PE pipe resins and PE100 RC pipe resins, illustrates the large progress in resin quality during the past four...

Author(s) : Gueugnaut Dominique

(Polyethylene, Non destructive technique, Ultrasonic Phased Array, Slow Crack initiation time) Since a few years it has been proved that - among the available concepts - the Ultrasonic Phased-Array technique (PA UT) was one of the most promising candidate for Non Destructive and Non Intrusive analysis of PE and...

Author(s) : E.J.W. van der Stok, F.L. Scholten, L.G.P. Dalmolen

A mathematical model was set up to assess the equilibrium gas pressure in the annulus of the reinforcement layer of an RTP pipe. This is done by using the theory of gas permeation, ruled by Fick's Law and the theory for a temperature gradient over the pipe wall, ruled by Fourier's law. The model allows calculating the...

Author(s) : Frans Scholten and Mannes Wolters

PA11, PA12 and plasticized PA6.12 pipes are interesting candidates for gas transport and distribution pipelines at 16 bars pressure, which is beyond the maximum pressure for PE100 pipeline systems (10 bars). However, PA pipelines are not meant as an alternative to PE pipelines, but to steel pipelines. Therefore,...