AMPP Store - Products tagged with 'dc stray current'

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A Novel Approach to Assessing Stray Current Interference without Potential Interruption

Product Number: 51324-20452-SG

Author: Parker B. Robbins

Publication Date: 2024

$40.00

A novel approach is proposed to assess a procedure for testing whether a pipeline may be interfered with from DC stray current. With the rise in popularity of portable coupons in AC mitigation testing, the paper proposes a method to evaluate DC stray current with a portable or stationary coupon without requiring potential interruption on foreign structures. This may allow technicians to conduct additional testing on suspected interference spots without requiring the interruption of a foreign pipeline or structure. This paper outlines and proposes a procedure for determining the likelihood of DC stray current interference utilizing coupons. Additionally, the paper recommends and outlines a proposed study to assess the accuracy of the techniques in the proposed procedure. While DC current cannot typically be measured and quantified for a bare metal holiday on a pipeline, coupons allow for a controlled and measurable connection to a simulated pipeline holiday. The procedure may be utilized to distinguish when suppressed potentials are occurring on a pipeline as a result of DC stray current interference rather than from inadequate current provided by CP system, a foreign voltage gradient, shielding or electrical grounding, even when the source of current is unknown. The procedure may also be beneficial in situations with atypical interring-structures where the existence of the interfering structure is unknown or where the applied voltage of the interfering structure cannot be interrupted traditionally such as with the prevalence of DC current situations occurring from installed or newly repaired direct-buried communication utility cables with weak splices at unknown locations. The procedure may also be utilized as an initial step to determine first steps in a DC stray current interference situation.

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Evaluation of Corrosion Risk by DC Stray Current: a Study of the EN ISO 21857 Standard Criteria

Product Number: 51324-20623-SG

Author: Clemence Rogier; Aymeric Lopitaux; Dominique Gauthier; Ahmed Fakhry; Sylvain Fontaine

Publication Date: 2024

$40.00

To assess and mitigate dynamic DC stray currents occurring on cathodically protected steel pipelines, the EN ISO 21857 standard was published in 2021. In this laboratory study, X70 steel ER probes buried in artificial soils under cathodic protection were submitted to anodic direct current influences. The impact on corrosion kinetics of anodic influences conditions was evaluated: triangular vs rectangular shape, anodic current densities from 0,1 to 10 A/m2, anodic period between 5 and 1800 s, and total anodic interference duration in one day from 0,5 to 10h. Soil environments were varied as well. More than 200 different test conditions were performed to better understand the parameters leading to a loss of metal. To complete this lab scale work, 8 on-site studies were performed as well. Real corrosion kinetics measured by corrosion probes were compared to corrosion risk prediction according to the new EN ISO 21857 standard. Pertinence of the criteria was demonstrated in this experimental study. It shows that to have the most precise prediction risk, reference levels such as defined by the standard (Eref and Jref) should be determined experimentally. In those conditions, 100% of real corrosion cases were predicted as such.

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Inductive and DC Stray Current Interference from Different HVDC Transmission Line Systems on Metallic Pipelines

Product Number: 51323-18925-SG

Author: Boshra Momen Nejad, Brandon Miller

Publication Date: 2023

$20.00

Back in 2018, we published a paper on a joint industrial R&D project, during which we performed detailed field measurements on selected pipeline segments in close vicinity to a High Voltage Direct Current (HVDC) transmission line during planned staged fault tests on the power line. Induced voltages on these pipelines were recorded during the HVDC staged fault process, which was conducted by the utility company. The measurement results from these tests were used for further validation or modification of an existing industrial guideline that focuses on the influence of HVDC power lines on metallic pipelines. Verification of future modeling results was another expected outcome of this study.

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Stray Current Interference Simulation and Mitigation Associated with Light Rail Transit (LRT) Systems and Adjacent Metallic Pipelines – A Case Study

Product Number: 51323-18926-SG

Author: Boshra Momen Nejad, Jeffrey Delorme, Brandon Miller

Publication Date: 2023

$20.00

During operation of DC rail transit systems, DC current will follow the path of least resistance when returning to the Traction Power Substations (TPSS) to complete the electrical circuit. If the track-to-earth resistance (resistance between the train rails and surrounding soil) is not sufficient, current can leak off the LRT track system into the surrounding soil. Metallic facilities such as pipelines in the soil offer lower resistance paths for the current while returning to the TPSS.

Products tagged with 'dc stray current'

A Novel Approach to Assessing Stray Current Interference without Potential Interruption

Evaluation of Corrosion Risk by DC Stray Current: a Study of the EN ISO 21857 Standard Criteria

Inductive and DC Stray Current Interference from Different HVDC Transmission Line Systems on Metallic Pipelines

Stray Current Interference Simulation and Mitigation Associated with Light Rail Transit (LRT) Systems and Adjacent Metallic Pipelines – A Case Study

Association for Materials Protection and Performance