The German technical system of rules for pipelines implements the European guidelines for the adjustment of the legal system of the member states into national legislation. Extensive detailed regulations have been created which enable an open market for the planning and construction of pipelines.
The detailed regulations refer wherever possible to harmonized European standards.
The regulations for the operation of long-distance pipelines are however still subject to national regulations.
However, unlike the most other national regulations, the German system of rules has no particular standards for the evaluation of defects in pipelines but only determinations and requirements for the dimensioning as well as for the inspection of new - faultless - components. These determinations basically apply to the entire operation time of pipelines up to the end of the lifespan. This circumstance can lead to problems e.g. in connection with the evaluation of defects on the basis of the inspection results of intelligent pigs.
In this paper we present a procedure developed by TÜV Rheinland, which embodies on the one hand the fundamental requirements of the German system of rules and enables on the other hand a practical method for the evaluation of defects.
The evaluation results are compared both with the results obtained by the ANSI/ASME B31 code, which is often used as a standard procedure by the in-spection companies using intelligent pigs, and the results according to the detailed RSTRENG procedure.