Observations on the resonance of buried pipelines with commercially-used frequencies 

Pipelines, the routes of which are located in the influence zone of high-voltage three-phase and/or AC rail-traction systems may be subject to AC influence.

by Dipl.-Ing. Wolfgang Vesper

Questions associated with intromission are dealt with in detail in AfK Recommendation No. 3, “Provisions for construction and operation of pipelines in the influence zone of high-voltage three-phase and AC rail-traction systems” published by the DVGW/VDE workgroup for corrosion-associated matters (AfK). Maximum pipeline/ground AC voltages can normally be anticipated at the ends of the influence sector. Practical investigations performed recently have, however, disclosed influencing cases in which a third voltage maximum was located well outside the influence sector or in which the AC voltage was higher at the end of a pipeline sector than at the start, with connection into the remaining AC-voltage-influenced piping system, with no intromission within the course of the route. In another case, a maximum, with a voltage of around 100 V, occurred at the mid-point of the influence zone, despite earthing at the ends (pipeline/ground AC voltage was only 2.1 V in this case). The cause of these phenomena is described below.

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published: Vulkan-Verlag GmbH, 3R 7 / 2004 (July 2004), 7|2004
Keywords: Energy Recovery, Material Recovery