Gueugnaut Dominique, Boujlal Adil, Rousselot Denise, Bouaffre Romuald
# 2012 Barcelona
(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 postponed selective replacement of the very first pipes laidone must be able to locate them easily in the field.As such a task is not possible by simply looking at the digital mapping system of the networks whereon are mentioned only limited operational information, GDF SUEZ’ R.& I. Division has proposed an innovative identification method consistingina physicochemical characterization of the “lost” material scrapped off from an old pipe on which an intervention is carried out. The characterization is made in the laboratory on very small quantities of material (ca. 30mg) by means of the Stepwise Isothermal Segregation (SIS) Technique on the basis of a specific protocol developed and adapted to cover the widestvariety of the PEs encountered. The “fingerprints” of the scraps are comparedto those integrated in a database currently established by GDF SUEZ’ R. & I. Division. The data presented in this paper demonstrate the feasibility of the overall procedure from the field to the laboratory.This method -whichcan beintegrated easily in the working/intervention plans of the operators-allows one to identify and in turn to locate precisely andselectively the oldest PEs while avoiding both large excavations and cost-effective pipe extractions.