Soil-Pipe-System
While the fundamental developments of modern corrosion protection systems for buried steel and cast iron pipelineswere coming to a temporary end in the middle of the 1980s, experience concerning optimum protection in different soils had also reached the stage that specific rules and regulations could be produced on this range of topics. First and foremost, this includes a determination of the corrosion likelihood for unalloyed ferrous materials depending on the most important soil parameters. This began with DVGW worksheet GW 9 “Evaluation of corrosion risks of buried pipelines and vessels in unalloyed and low-alloy ferrous materials in soils”. After 14 years of experience with the application of this data sheet, DIN 50929-3 “Corrosion of metals – Corrosion likelihood of metallic materials when subject to corrosion from the outside – Part 3: Buried and underwater pipelines and structural components ” was able to be published.
The experiences gained from the application of DVGW worksheet GW 9 are reflected the fact that, of the determining parameters available, only those which have proved able to be determined in practice have been adopted. Soil condition has been more sharply defined and given additional weighting on the basis of experience. Also, parameters which, in themselves, cause very high corrosive behaviour have been given more weight: soils with a high content of organic substances and contamination due to fuel ash, waste, scrap, effluents, coal and coke.
