How can I verify that the correct assembly procedures have been followed?
Traceability is an integral part of modern, sophisticated, Quality Assurance systems used for PE pipe networks. The systems available, and mandatory at many end-users, enable tracing through the whole process, from the resin batch at the PE producer, through pipe extrusion, the utility company and the installation contractor's operations. All installations can be traced back to the resin batch from which they were produced, with full data on the history of the pipe or fitting at any location.
The most up-to-date traceability systems are based on the use of barcodes. The barcodes can record data covering:
- fusion-jointing equipment data
- fusion-jointing equipment operator data
- site data (geographical location)
- data on fittings and pipes
- fusion-jointing parameters
- installation dates
- assembly procedures
This information on the barcodes can be affixed to the pipes and fittings insitu, and recorded in a database, ideally linked to a Geographical Information System (GIS). At any subsequent excavation or operation the barcode can be read and all data on the pipes and fittings concerned can be accessed. Similarly in planning operations and works the data is readily accessible from the GIS or database.
ISO 12176 Part 4 defines a traceability system for encoding the characteristics of the pipes, fittings, fusion-jointing equipment, fusion-jointing equipment operators and fusion-jointing protocols. It is applicable to PE pipes, fittings and valves conforming to ISO standards for gas supply piping systems and also to the assembly operation utilising methods such butt, socket and saddle fusion, electrofusion, induction fusion and mechanical jointing.
It is up to the user to create the link between the various elements in order to provide a complete traceability system. Care is necessary when determining which data are to be downloaded into the traceability system database and the minimum information to be stored in the database for later retrieval. The choice and the amount of data will strongly influence the performance of the database when it is used later.
Note that in a full traceability system fittings will have two barcodes; one for traceability and one for the fusion parameters. These are based on different barcode protocols so cannot be confused by the barcode reading equipment.
ISO 12176-4:2003 Plastics pipes and fittings - Equipment for fusion jointing polyethylene systems - Part 4: Traceability coding
Gueugnaut, D. Mise en place de la traçabilité; l'exemple des conduites de gas en polyéthylène à Gaz de France. Gas, Wasser, Abwasser (GWA); SVGW Zürich, October 2003.