2024 Abstracts

Abstracts of Papers Leuven 2024

1) KEMYA FRP Piping Network Comprehensive Strategy Study and RCM

Hassan Al-Hammad

The KEMYA FRP (Fiber Reinforced Plastics) network is the largest among SABIC affiliates that consists of approximately 130 km of piping, mostly underground (95%) in various water services. The FRP systems in KEMYA include Sea water system that is received by intake structure from MARAFIQ and returned to the MARAFIQ canal. Also, a takeoff from the base plant sea water return header provides make-up to a sea water cooling tower. Moreover, Firewater and potable water systems get pumped from dedicated firewater and potable water tanks, and the waste water and oily water from the units get cleaned before getting discharged back into Marafiq.
However, the strategy studied the mechanical design of FRP network. Also, went through the susceptible damage mechanism, history of major events, current vulnerabilities and other important factors.
This topic will go through the details of each system by presenting scope & boundaries of the study, operating context, functions & failure modes, risk profile, and recommendation of tasks. Also, the topic will have more analysis for thrust block evaluation, and end of life evaluation for old FRP network, especially the vintage ones that was constructed since 1981.

2) Assessing High Voltage DC Interference Risks on Buried Pipelines

Christophe Baete

Vaartdijk 3/603  B-3018 Wijgmaal (Leuven)
Phone: +32 16 474960  Fax: +32 16 474961
E-Mail: info@elsyca.com  Web: www.elsyca.com

High voltage DC (HVDC) powerline systems typically transport energy over long distance with a smaller ecological footprint than the high AC voltage counterparts. There are 187 operational or planned HVDC systems worldwide causing a potential safety and corrosion risk for pipelines. These threats often occur unexpectedly when the operating mode of the HVDC changes. An overview of the different HVDC systems will be provided. Computational modelling technology was used on a real world case to define the operational conditions of the HVDC system that lead to integrity and safety threats and how these can be properly mitigated.

3) Materials matter: a case study on Slovenian internal plumbing installations and their impact on lead content in drinking water

Nina Gartner*, Mirjam Bajt Leban, Tadeja Kosec

Slovenian National Building and Civil Engineering Institute, Laboratory for Metals, Corrosion and Anti-corrosion Protection, Ljubljana / Slovenia; *nina.gartner@zag.si

Slovenia is renowned for its high-quality drinking water resources; however, the selection of materials in water supply systems can significantly impact water quality for end consumers. The presence of any lead (Pb) concentrations poses a serious threat to drinking water quality, often originating from lead remnants or modern brass materials installed in domestic distribution systems, influenced by water characteristics such as pH and carbonation levels. Slovenia lacks systematic monitoring of lead levels in drinking water, and there is no available data on the materials used in our domestic distribution systems. Moreover, the analysis of lead concentrations in drinking water is not correlated with the type of drinking water, considering hardness, pH, and other influencing factors. The results of a study within the national target research programme (V3-2234, 2022-2024) will be presented. The aim of this study is to collect data on the presence of materials with lead content in Slovenian domestic distribution systems and to investigate their relation to elevated lead levels in analysed drinking waters. Its goal is to help identify the risk posed by Pb in drinking water. Consequently, the results will assist policy makers and water authorities to develop strategies for reducing lead exposure due to the use of inappropriate materials in Slovenian domestic distribution systems.

4) Solving challenges related to large scale rollout of 11000 cp remote monitoring devices for the Dutch Gas grid operator.

By Pieter Hogeveen, Withthegrid, The Netherlands

The objective for a Dutch TSO was to automate their periodic test post measurements in order to detect outages earlier, reduce operational costs and solve issues related to lack of technical personnel. Three challenges for this solution were addressed; 1) Determine interference sources that might only occur at specific moments near the protected structures outside of measurement windows. Solved by a drift in time of the measurements that will give insight of every minute of the day after monitoring for a year. 2) Detection of potential drift of the reference cell as the buried cells cannot be calibrated over time. When undetected, data might be misinterpreted and will result in a poorly evaluated CP structure. Solved by measuring and comparing two different types of reference cells. 3) Correct installation and monitoring at scale with 11K IoT modules in the field were ensured by easy installation with tailormade IoT modules for the test poles and using the CP monitoring platform already during the installation phase for issue management related to installation (e.g. trigger an issue for incorrectly connected reference cells).

5) Elucidating ductile iron pipeline corrosion in acid soil
containing iron-oxidizing bacteria

Fumio Kajiyama, Dr.
Tokyo Gas Network Co., Ltd., 1-5-20, Kaigan, Minato-ku, Tokyo 105-8527, Japan

Severe external corrosion of ductile iron pipe as high as 0,405 mm/y was observed in acid soil. Detailed field studies identified high numbers of iron-oxidizing bacteria (IOB). In response to the external ductile iron corrosion problem in the field, a laboratory study using ductile iron coupons, in aqueous medium inoculated with Thiobacillus ferrooxidans (IOB species) or IOB soil, was undertaken to realize the IOB influenced corrosion. Results of field and laboratory studies are used to draw conclusions regarding the elucidation of action of IOB in the processes related to corrosion.
Key words: ductile iron pipe, Iron-oxidizing bacteria, Thiobacillus ferrooxidans, acid soil, scanning vibrating electrode technique (SVET), fluorescent microscope, electrochemical measurements

6) Investigations of the failure of drinking water component made of brass

Mirjam Bajt Leban*, Tadeja Kosec and Petra Močnik

Slovenian National Building and Civil Engineering Institute, Laboratory for Metals, Corrosion and Anti-corrosion Protection, Ljubljana / Slovenia; *mirjam.leban@zag.si

In this investigation two different brass drinking water components, which were a part of internal installations, were investigated. In both components, a leakage of water was detected in a relatively short time after installation.
The first case study concerns brass T joint nipple connecting alu-plast pipes. A leakage occurred on several brass T joint nipple components, parts of warm water circulation unit, three years after installation. Examination by scanning electron microscopy and metallographic analysis revealed features, characteristic for erosion corrosion. The reasons for this type of corrosion failure were an installation error that caused an unfavourable water flow regime and severe softening of water which disabled formation of scale deposition inner surfaces of brass components.
The second case study presents a failure of brass nipple connection to valve. Failure of this component occurred only three months after installation. Detailed investigation showed that stress corrosion cracks propagated from the inner plain side in the contact with water towards outer surface with thread. The measured Brinnell hardness of brass component under investigation was around 125 HB for failed and 112 HB for unused, which was higher than recommended 110 HB by DWGV W 534 technical regulation, which might be one of causes for induced SCC.

7) Deep optimization for Cathodic Protection: advanced technology for T/Rs output current optimization.


Automa S.r.l. – Via Casine di Paterno, 122/A – 60131 Ancona – Italia

Cathodic protection (CP) is a crucial technique for safeguarding metal structures from corrosion. In the context of modern infrastructure, digitalization plays a key role in enhancing the efficiency and effectiveness of CP systems. This paper explores an innovative approach to cathodic protection, focusing on the development of advanced technology that optimizes the output current of transformer rectifiers (T/Rs) through deep optimization techniques.
Traditional CP systems often operate without the flexibility to adapt to changing environmental conditions and structural requirements. The proposed technology leverages digitalization to remotely control T/Rs and fine-tune their output current. This adaptability is achieved by harnessing real-time feedback from IR-free potentials measured in critical test points of the CP system.
Key components of this novel approach include the integration of remote monitoring units (RMUs), which are powered by small solar panels, and their ability to collect and transmit real-time data from critical test points. By analyzing this data, the system can make rapid and accurate adjustments to the output current, ensuring optimal corrosion protection.
This leads to a significant reduction in energy consumption, as the T/Rs can operate at their most efficient levels. Furthermore, it enhances the lifespan of anodes and reduces maintenance costs. The RMUs and deep optimization algorithms also provide a proactive approach to maintenance by detecting potential issues before they become critical, ensuring at any time effective corrosion protection.

8) 100 mV shift criterion application in a Gas Distribution Network
by means of coupon.


Automa S.r.l. – Via Casine di Paterno, 122/A – 60131 Ancona – Italia
ivano.magnifico@byautoma.com L.SPISNI Inrete Distribuzione Energia S.p.A. – Via Cristina Campo, 15 – 40127 Bologna – Itala

This paper presents a comprehensive investigation into the practical application of the One Hundred Millivolt (100 mV) Cathodic Polarization Criterion to assess Cathodic Protection effectiveness by means of coupon on underground pipelines in a Gas Distribution Network.
The One Hundred Millivolt Cathodic Polarization Criterion is a widely recognized criterion for assessing the effectiveness of CP systems particularly in those areas where the -850 mV Potential criterion is difficult to respect due to the higher soil resistivity or the network configuration.
When using the criterion by evaluating the 100 mV shift by measuring the depolarization after disconnecting the CP current, the instant-off potential to consider as the reference value is often measured too late, thus loosing completely the overvoltage generated by activation polarization that generally disappears in the order of few milliseconds.
In this study, a deep investigation on applying the criterion by measuring depolarization on coupons is given, evaluating on real field measurements the effect of the waiting time on taking the reference value from coupon disconnection, as well as the effect of changing in soil resistivity considering different periods of the year.


9) The coextrusion technology leading to the development of a unique corrosion prevention solution.

Luc Perrad, DENSO GmbH, Leverkusen, Germany

The first polymeric tapes were launched in the pipeline industry in the mid 1950ies. Polymeric tapes have been used worldwide for the external corrosion prevention of buried pipelines since then.
From the beginning, mostly PE- or PVC-carrier foils were coated on one side with an adhesive layer based on bitumen mastic, mastic or butyl-rubber in the tape manufacturing process.
The most common tape production process is laminating an adhesive layer onto a PE-or PVC-carrier foil. Many tape coatings, especially 2-ply tapes, are manufactured in this way. By repeating the lamination process and adding an adhesive layer on top of the PE-carrier foil, a 3-ply tape structure can be achieved.
A more sophisticated and complex way to produce tapes is to manufacture them in a coextrusion process. The coextrusion process technology requires more than one polymer melt stream as each melt stream is produced by its own extruder. This process requires a lot of technical expertise. However, the effort is more than justifiable, since the product properties and, in particular, the long-term behavior are significantly increased and improved.

10) Computation and Mitigation of Electromagnetic Interferences due to Railway Stray Currents

30 avenue du Général Leclerc 38200 VIENNE: 04 26 05 33 18 —

In general, trams and trains are powered by direct current. When a steel pipeline is located near a continuously electrified railway track, it might be victim of interferences. For instance, a pipeline can be subject to electromagnetic interferences generated by stray currents which can lead to very rapid corrosion.
In the shared corridor, all internal and external metallic structures, and installations, such as civil works (viaducts and tunnels), pipelines and cables structures are victim of electromagnetic disturbances and potentially threatened by stray currents. These are due to the return currents between the railcar and the supply rectifier which generates in the rails a longitudinal voltage drops. The soil being electrically parallel with the rails, a part of the return current flows as stray current from earth to the power supply rectifier depending on the soil resistivity and the potential rail/soil. The danger of corrosion is particularly important for earthing systems, because they are often electrically connected between them over large distances.
In this paper we propose to numerically estimate the effect of stray currents such as those produced by DC rail traction systems on the corrosion of buried metallic structures in a multi-region soil model. A rigorous analysis performed with CDEGS on a realistic case allow to assess the effects of electromagnetic couplings and design mitigation measures to fulfill European standards.

11) Cathodic corrosion protection of underground pipelines:
On the contribution of hydrogen loading to stress corrosion cracking

Markus Büchler
SGK Zurich, Switzerland

Hydrogen loading of steel is often considered to relevantly affect the durability of buried pipelines and bear the risk of stress corrosion damages. Hydrogen loading is possible from the outer steel surface due to high levels of hydrogen generation with increased levels of cathodic protection. Additionally, the increasing relevance of hydrogen transport in pipeline systems raises the question with respect to hydrogen loading from the inside of the pipeline. In order to assess the contribution of the level of cathodic protection the possible damages associated with hydrogen occurring on pipelines are discussed. Their contribution to the damage process have
been investigated in laboratory tests with various configurations of disbonded coatings, which are typically associated with stress corrosion cracking. The associated results are presented and conclusions with respect to the implication for the future transport of hydrogen are discussed.

12) Comparative Analysis of CMI and DCVG in Corrosion Protection for
Buried Pipelines

By Markus GLINKA, Electromagnetic Pipeline Testing GmbH, Germany

This presentation offers a detailed analysis of Current Magnetometry Inspection (CMI) versus Direct Current Voltage Gradient (DCVG) for evaluating corrosion protection in buried pipelines.
The ability of CMI to detect a wider range of coating defects, including smaller ones, is crucial for accurately assessing the state of steel at a pipeline under Cathodic Protection (CP). The analysis reveals the comprehensive detection capabilities of CMI in identifying and assessing defect severity and corrosion status. In contrast, DCVG, while effective, shows limitations in such detailed assessments. The data suggests CMI’s enhanced effectiveness in providing insights into the integrity and efficacy of CP, particularly in complex scenarios.

13) Bacterial corrosion on pipelines:
Causes, consequences and possible solutions

by D. Joos (SGK Swiss Society for Corrosion Protection,
Technoparkstr. 1, CH-8005 Zürich, david.joos@sgk.ch)
M. Büchler (SGK Swiss Society for Corrosion Protection)

The history of cathodic protection (CP) has not only always been linked to the structure to be protected but has also been closely connected to the electrolytic environmental conditions. At east when corrosion damages occurred on buried gas pipelines despite compliance with the originally applicable protection criterion. In these cases, poor bedding, and the involvement of  sulphate-reducing bacteria in the corrosion process were identified. From then on, in addition to the chemical and morphological properties of the electrolyte, the bacterial influence was also a factor to be considered in the case of buried pipelines, which was often held responsible as a possible cause of damage to pipelines. In order to determine possible corrosion damage mechanisms, laboratory tests were carried out. These tests were performed under different electrolyte conditions that mimic the possible contribution of bacterial activity, without the actual presence of bacteria being necessary to gain a better understanding of their effects on corrosion. The following article presents the tests carried out, the results obtained, and the conclusions drawn from them.

14) Specification, Design, Installation, and Commissioning of Cathodic Protection
Systems for mixed Hazardous and Non-Hazardous Locations

by Marcus HARDY,

The world is changing to be more risk adverse, this is becoming more and more evident on large industrial sites, be they petrochemical or food process. Operators and designers are making decisions to classify electrical systems as Hazardous Area rather than Non-Hazardous, this not only provides future proofing for their plants, but also reduces the possible impact that lack of maintenance might present in the future. This presentation gives an overview on where this impacts a typical Cathodic Protection installation and what considerations you should make to ensure a cost effective well engineered project whilst maintaining full compliance with the relevant standard.

15)  CP measurements by coupons / When the values are bad …

Francois CASTILLON TEREGA Coordination Technique / Inspection
E-Mail: francois.castillon@terega.fr

Since 2003, Terega, which operates a 5100 km long gas network in the southwest of
France, uses permanent coupons on each test point (4000 TP) to assess the CP
efficiency, disconnecting pipe/coupons measurements to do so.
Like any cathodic protection operator, for the potential values, we must comply with
ISO 15589-1 Table 1 which partly depends on the resistivity intervals.
How do we deal with the bad values measurements on coupons before increasing
the current flow of PC ?
This presentation is showing how to manage when the criterias are not obtained.

16) Cathodic protecton on carbon steel in heterogeneous corrosion conditons

Federico Martnelli-Orlando1, Leandra Gallat1, Andraž Legat2, Ueli Angst1
1Insttute for Building Materials, ETH Zurich, Zurich
2Slovenian Natonal Building and Civil Engineering Insttute, Dimiceva 12, 1000 Ljubljana,Slovenia

The effect of cathodic protecton (CP) on carbon steel has been intensively studied in the last century. Several studies investgated the changes in the electrolyte chemistry (i.e., pH and oxygen concentraton) as well as modificaton at the steel surface upon the applicaton of CP.
However, a significant number of these studies focuses on the effects provoked by the applicaton of CP considering the steel as a homogeneous electrode. On the other hand, the effect of CP on heterogeneous electrodes (e.g., galvanic elements) has been debated for several years. In partcular, it is debated whether the applicaton of CP results in a reducton in the size and number of the corroding areas, or in a reducton of the corrosion rate not affectng the number or size of the corroding areas. The aim of this work is to study the effect of CP on carbon steel in presence of galvanic elements in order to contribute to a better understanding of the underlying mechanisms to establish criteria for the applicaton of an effectve CP system. In this work, CP is applied on coupled multelectrode arrays (CMEAs) of
carbon steel electrode buried in saturated quartz sand and the individual current flowing in each electrode is measured by means of a desktop multmeter. Results show that the applicaton of cathodic protecton potental even lower than -0.85 VCSE might not be enough to guarantee all the electrodes to have a corrosion rate lower than 10 μm/y.

17) Study of on-off time measurement configuration in coupons with dataloggers.

Ignatio Montero Sanz

Nedgia, SA (the main natural gas supplier in Spain), has been monitoring the off potential in coupons with dataloggers since 2009.
The international standards stablished that off potential measurements in coupons should be taken as soon as possible after the switch off.
Our on-off configuration in data loggers has been stablished since 2009 in the same configuration (27 sec on, 3 secs off, and we took the off measure after 100ms).
Recently we change it, And now we take measures each second taking the off potential asures after 1 ms.
These changes have showed us a very important variation in the off potential values, that implies to adapt all our Rectifiers.
We will analize the measurement data with several conditions as soil types, rainfall,
pipelines characteristics…
In the paper will be demonstrated that the new on-off configuration comply with our
requirements reducing the IR measurement errors.

18) AC Mitigation System After Ten Years of Operation

Jerzy Sibila, Jerzy Mossakowski
Corrstop Co. Ltd, ul.Kamienna 87, 62-023 Kamionki, Poland

This case study presents experience from ten years of operation of an AC mitigation system for an underground gas pipeline exposed to the interference of overhead 400 kV and 220 kV power lines running in parallel.
In 2012, thirteen solid state decouplers (SSD) were installed on the gas pipeline and as a result, the measured interfered AC voltage and current densities were reduced to acceptable thresholds. However, since 2012 the load on these three overhead voltage lines has increased significantly and the present measured AC current density at one of the points with the SSD is as much as 595 A/m2. Nevertheless, the measured corrosion rate on the ER probe is only 5,01 um/year.
It seems that the allowable corrosion rate below 10 μm/year is due to the fact that the ON potentials for this pipeline are less negative than -1.2 V (CSE).


19) Impact of AC-corrosion on lead

Jonas Engblom
RISE Research Institutes of Sweden AB 

info@ri.se  www.ri.se

The main method of energy transfers across larger bodies of water rely on large diameter cables placed in water or sediment. While the composition of such cables may vary, one type relies on a lead mantel covered with a copper reinforced PE-mantle to keep the water away from the electrically conducting core. As such, the integrity of the lead mantle is of high importance to ensure the technical lifetime of the cable. In case of a damage to the external PE-mantle, the lead mantle will be exposed to the surrounding sea water and/or sediment, with corrosion as likely result. However, as the current flow of the core induce an AC-voltage on
the lead mantle, AC-corrosion is also a concern. In the following paper a laboratory study is presented which is based on actual values from a project in Sweden. The laboratory study aimed to investigate how the corrosion impacted lead depending on the current density, as well as how the AC-corrosion was impacted on the galvanic coupling with copper.


By Ken LAX, Corroconsult UK Ltd

EN ISO 24695 is in the early stages of development by ISO, with a collaboration with CEN (Vienna Agreement). The standard will provide cathodic protection engineers with the necessary information to quantify and manage the corrosion risks. The intention is to provide guidance for steps that should be taken during the planning stages, as well as during the operation of the pipeline.
This presentation for CEOCOR will briefly explain the different types of HVDC systems that you are likely to encounter and how the DC is converted back to AC. Design and mitigation methodologies will be discussed.
The standard will provide calculation examples for the assessment and mitigation of interference.

21 ) Environmental conditions of buried pipelines

By Dr Sarah Leeds (DCVG Ltd)

Corrosion of steel in soils is a major concern for the oil, gas, water and electrical communication industries, etc, particularly as the buried infrastructure is aging. Increasing stringent environmental protection requirements such as those set by the Federal Energy Regulatory Commission (FERC), Department of Transportation (DOT) in USA, CONCAWE in Europe and United kingdom Onshore
Pipeline Operators’ Association (UKOPA) who are all placing focus on corrosion issues. As the world is placing more emphasis on the environment to maintain it for future generations it only seems right that more thought should be considered in regards to the environmental conditions of pipelines buried in soils. Variations in soil composition and properties have a major impact on corrosion, which
can range from rapid to negligible. Corrosion in soil is an aqueous process and the mechanism is electrochemical but the conditions of soil can range from atmospheric to completely immersed. The type of condition depends on the compactness of soil and the water or moisture content. Moisture retained in soil under field dry conditions is largely held within capillaries and pores of the soil. Hence
a dry sandy soil will generally be less corrosive than wet clay. There are many characteristics of soils that make a corrosive environment. Actual corrosiveness depends on the interaction between rainfall, climate and soil reactions. A characteristic of soil is its heterogeneity. Varying composition or structure
can result in different environments acting on different areas of the same metal surface. This can give rise to differing electrical potentials at the metal/soil interface causing the establishment of cathodic
and anodic areas and consequent passage of charge through the metal and through the soil (long line currents). Differences in oxygen concentration (differential aeration) or differences in acidity or salt concentrations can give rise to corrosion cells. The conductivity of the soil is also important; a high conductivity is conducive of a high corrosion rate. Overall all properties that affect the corrosive nature
of pipelines when buried in soils will be reviewed. This will entail discussing features such as classification of the soil type, soil moisture content, oxygen content, soil resistivity, soil redox potential, the effect of soil pH, the soluble salt content (which will include discussing the major cations, which are sodium, potassium, calcium and magnesium and the major anions which are chloride, sulphate and carbonate effects on the soil corrosiveness), soil redox potential and microbial activity in soil (SRB’s, iron bacteria, of iron-oxidising bacteria). A comparison will be made regarding the changes that occur when the pipeline has been cathodically protected and the effect that it has on the discussed environmental properties of soil.

Keywords: environmental soil conditions, cathodic protections, soil compositions, oxygen concentration, soil classification, conductivity of soils, soil classification, soil moisture content, oxygen content, soil resistivity, soil redox potential, soil pH, soluble soil content, microbial activity

22 )Understanding Buried Pipeline Damage from Direct
Lightning Strikes – Strategies and Challenges

By Nikolaos Kioupis, Hellenic Gas Transmission System Operator (DESFA), Athens Greece
Theagenis Manolis, Hellenic Gas Transmission System Operator (DESFA), Athens Greece
C.A. Charalambous, Department of ECE, University of Cyprus, Nicosia Cyprus
Nikolaos Kokkinos, ELEMKO, SA, Athens Greece

Lightning strikes pose significant threats to buried pipelines, potentially resulting in
detrimental consequences if not adequately managed. This presentation/paper is motivated by recent incidents on the Hellenic Gas Transmission System. These incidents involved pipeline damage (deep metal loss or perforation of pipe wall) from direct lightning strikes and have prompted an in-depth exploration of strategies and challenges in mitigating such risks.
Firstly, the paper/presentation will focus on key considerations such as evaluating how well pipelines withstand lightning strikes and understanding the factors that make them more vulnerable. To this end, risk analysis plays a crucial role in identifying vulnerabilities and implementing effective measures to prevent damage. In our presentation, we will demonstrate that there is a need to develop strategies that involve thoroughly assessing risk factors and proactively taking steps to minimize the likelihood of failure.
Moreover, the presentation will address the intricate connection between pipeline damage from lightning strikes and the onset of corrosion issues. It will also elucidate how existing corrosion and coating defects may facilitate pipeline damage from lightning strikes, posing additional challenges to pipeline integrity and maintenance practices. Therefore, we will emphasize the importance of comprehensive CP upgrading initiatives, continuous monitoring, detection, and repair of small coating defects to prevent corrosion and structural deterioration.
Finally, we will briefly outline the crucial roles of earthing, dc decoupling devices, and sparkgaps in lightning strike mitigation strategies, as these components play significant roles in dissipating electrical energy and preventing damage propagation along pipelines.
By elucidating these critical considerations and mitigation strategies, this work contributes to advancing the discourse on safeguarding buried pipelines against the adverse effects of direct lightning strikes, ensuring the sustainability and reliability of critical infrastructure networks.

23 ) An overview of the newly developed survey platform on an unmanned boat that enabled DCVG and CIPS surveys to be carried out using remote control technology to locate coating defects and obtain a corrosion protection profile of submerged pipelines

By Rashad Mammadov (Scan4Pipes),
Walter E. Siegmund (Scan4Pipes),
Lothar Kreutzwald (ESK
Dr Sarah Leeds (DCVG Ltd)

The DCVG technique has been a well-established technique for over 40 years for locating coating defects on coated buried steel pipelines. Typically the equipment that has been used for DCVG surveys has been composed of a specially designed sensitive millivoltmeter, connected between two Cu/CuSO4 half-cells (reference electrodes) and used to indicate any imbalance when the half cells straddle the voltage gradient in the soil. In the coating defect voltage gradient when one half cell is placed about one to two metres from another similar half-cell, one of the two reference electrodes will adopt a more positive potential and this influences the direction and amplitude of the swing of the millivoltmeter needle indicating the current flow to the coating fault and hence pinpointing the coating defect epicentre. A CIPS meter has also been customised whereby the pipe-to-soil potentials
can be logged whilst on the unmanned boat to carry out a full corrosion protection profile of submerged pipelines. This has all been possible with the introduction of modern technology enabling remote control devices to be developed that can be placed on an unmanned boat and controlled from onshore to locate coating defects and carry out a full corrosion protection profile of submersedpipelines. This paper will give an overview of the findings from this new survey platform on the unmanned boat. To be able to perform ECDA survey on remote location with remote controlled DCVG unit Scan4pipes designed a special unmanned autonomous autopilot-controlled pontoon. The unmanned autonomous autopilot-controlled pontoon developed by Scan4pipes offers several advantages for performing ECDA surveys on remote locations. The pontoon is specifically designed to operate without a human onboard, relying on advanced autonomous technology and autopilot systems for its navigation and control. The pontoon is made of fiberglass and has a flat-bottomed design, providing stability and ample deck space for carrying out various survey purposes such as depth of cover survey, DCVG and CIPS surveys. It can also serve as a floating platform for equipment or events. One of the main advantages of the specially designed pontoon is that it eliminates the need for a human operator or crew onboard. Instead, it utilizes an autonomous control system that incorporates sensors, GPS technology, and algorithms to guide its movement along the pipeline during ECDA or depth of cover surveys. The autopilot feature enables the pontoon to manage its course speed, and other parameters without direct human intervention. It can be programmed to follow preset routes, avoid obstacles or hazards, and make adjustments based on weather conditions or other external factors. This level of automation enhances safety and eliminates the risks associated with human-operated vessels. In summary, the unmanned autonomous autopilot-controlled pontoon developed by Scan4pipes is specifically designed to perform ECDA and depth of cover surveys and other related tasks in remote locations. It offers several advantages such as increased safety, costefficiency, and the ability to access hazardous or remote environments without putting human lives at risk. With its advanced autonomous technology, sensors, and GPS systems, the pontoon can
navigate and control its movements along the pipeline during surveys. Its flat-bottomed design provides stability and ample space for carrying out various survey purposes. Overall, the unmanned pontoon is a highly advanced and versatile solution for performing DCVG surveys on remote locations.
The success of the unmanned autonomous autopilot-controlled pontoon in performing ECDA surveys has been demonstrated through field tests conducted with DCVG Ltd and during real ECDA surveys for various pipeline operators such as Westnetz GmbH and Thyssengas GmbH. During real ECDA pipeline SLB-Private surveys with remote control DCVG unit installed on pontoon operator was able to successfully locate coating faults and record relevant fault data from remote location. This highlights the effectiveness and reliability of the pontoon in conducting ECDA surveys in real-world scenarios. The autonomous control system, coupled with advanced sensors and GPS technology, enabled the pontoon to navigate along the pipeline and carry out accurate surveys. The findings from these surveys can assist pipeline operators in identifying and addressing coating faults, thereby ensuring the integrity and safety of the pipeline system. Overall, the unmanned autonomous autopilot-controlled pontoon developed by Scan4pipes offers a practical and efficient solution for performing ECDA surveys on remote locations.
Its ability to operate without a human crew reduces risks and costs, while its advanced technology enables accurate and comprehensive survey results.

Keywords: DCVG, coating defects, pipelines, unmanned boat, remote control DCVG, CIPS, survey platform, corrosion protection profile, pontoon, ECDA surveys.

24 ) Materials in contact with drinking water – A review

Timo Jentzsch, Angelika Becker
IWW Water Centre, Muelheim an der Ruhr, Germany

Corrosion of metallic materials in contact with drinking water can cause failures of distribution pipes or other components (water loss, water damage, blockage of valves etc.). But on the other hand it is also possible that the metallic materials leach metal ions into the water which can result in hygienic problems when limit values (drinking water directive, technical guidelines, WHO recommendations etc.) are exceeded. In this case it can be seen as a corrosion damage of the water itself. This paper is intended to maintain awareness of this kind of corrosion damage by giving a review of the various material-water-interactions as well as the development and advancement of regulations and guidelines regarding this topic.

25 ) Percolation sensors for the detection of corrosive liquids under isolations.

By Helge Pfeiffer, Rémy Fauche, Ruben Windey, David Seveno, Martine Wevers, KULeuven

Sensing concepts for monitoring the integrity of engineering structures operate in a quasi-linear mode showing inherent disadvantages. An interesting alternative is provided by sensors having sigmoidal response curves that depends only on an external parameter associated with a specific damage degree. They are usually based on phase transitions, crack phenomena or related physical principles and often show responses that span many orders of magnitude. This results in some independence from baseline variations, which increases the probability of detection compared to
many other technologies.
This presentation will report on successful applications of this sensor concept, such as the detection of corrosive liquids in operational industrial pipelines, aircrafts and the penetration of moisture into composite materials.