Interference from dc traction systems can result in pipe-to-soil potentials outside of the acceptable limits.
The Q method is an established procedure for evaluating the time varying potentials and empirical guidelines have been developed to allow a judgement of the corrosion risk caused by the interference.
The method can be used to evaluate current densities as well as potentials.
Corroconsult UK Limited are proud to announce a new product line.
This next generation of transformer-rectifiers offer the user absolute control over the TRs configuration in real-time with the added benefit of in-built remote monitoring of key measurements.
The TRs can be viewed and configured in real-time through web based applications that are compatible with Windows / Macintosh / Android / iOS platforms.
Each initial order is provided with a lifetime single user access to the online database (additional lifetime user licenses can be purchased separately). There are no hidden ongoing subscription costs.
Each unit can be designed specifically to client requirements and is assembled and tested in the UK by Corroconsult personnel in accordance with the Company Quality Management System (ISO 9001-2015).
Take control of your impressed current cathodic protection (ICCP) systems.
Contact us for a live demonstration via video conferencing.
Corroconsult are pleased to announce the result of their latest UVDB Verify Audit (Category B1) has seen the Company achieve a 100% pass mark in all aspects.
This is in no small part to the ongoing contributions to the QHSE management systems being monitored and implemented by both Peter Rosie (Office Manager) and Diane Singleton (Business Support Manager).
A special mention also goes to Anthony Thomas (Corrosion Engineer) for hosting the UVDB auditor during his on-site inspection.
This flawless mark is indicative of our Company’s dedication to not only seeking to monitor our QHSE systems, but to also pro-actively improve them.
Supplier Name: Corroconsult UK Limited
Supplier ID: 61703
Audit Level: Verify B1
Audit Date: 22/08/2019
MSE
CSR: 100%
Environmental: 100%
Health and Safety: 100%
Quality: 100%
SITE
Environmental: 100%
Health and Safety: 100%
Quality: 100%
We are currently looking to recruit Cathodic Protection Senior Engineers and Technicians for projects in the UK and overseas.
iCorr or NACE accreditation for onshore CP essential.
Submit your CV to cv@corroconsult.com
We look forward to hearing from you.
The following paper was presented at CEOCOR – Brussels, Belgium – 19th – 22nd May 2014.
The paper was authored by Ken Lax, and presented by Ken at the conference.
DISCLAIMER: All information, references to Standards and / or criteria correct at time of paper.
Kirchhoff’s Laws are the foundation for many network analysis techniques.
Cathodic Protection systems are essentially d.c. electrical networks and the distribution of current follows these laws.
Most CP applications will not require any knowledge of these laws but sooner or later every CP practitioner will need to apply and understand them.
By the end of this presentation you will be able to apply Kirchhoff’s Laws and resolve the simultaneous equations using matrix algebra.
An understanding of Kirchhoff’s Laws, and the ability to apply them, will enable you to understand:
We will only be considering d.c. circuits in this introduction.
Kirchoff's Current Law (KCL) and Kirchoff's Voltage Law (KVL) will add to the existing knowledge of CP engineers and designers and help to explain some of those mysterious situations that cannot be explained just by Ohms Law.
Passive sign convention: Current enters a passive device at its POSITIVE terminal.
Current: Measurement of the electric charge passing through a given point within a certain amount of time. Units are Coulombs per second (amperes).
Voltage: measures the amount of energy required to move a given amount of charge as it passes through a circuit. Units are Joules per Coulomb (Volts).
Junction: Any place where two or more wires come together.
Branch: Anything that connects two junctions
Node: A point in the circuit
Also known as the JUNCTION rule. Conservation laws tell us that electrons must behave in a certain way when connecting devices to make a circuit. The electron behaviour governs the voltage and current around the loops and at the nodes. So Kirchhoff’s Laws apply whatever devices are used in the circuit since it is a law of conservation of charge (KCL) or energy (KVL).
The sum of the currents entering any junction must equal the sum of the currents leaving that junction.
Also known as the LOOP rule.
The sum of the potential differences across all elements around any loop must be zero.
With respect to cathodic protection systems, the term "electrical isolation" relates to confining the (cathodic) protective current to the structure being protected.
In terms of electrical separation this could mean isolating;
Electrical isolation is a key factor in the successful application of cathodic protection where it has been included at the design stage. For the purposes of this blog article we assume that the structure is intended to be electrically isolated.
That is not to say that electrical isolation is always required, as long as the designed system has taken this into account.
There are times when it may not be desirable, or even practical, to isolate protected from unprotected structures. Examples are refineries, industrial plants, large tank farms and similar complex facilities.
Commercial fittings for providing electrical isolation of pipework include;
Cathodically protected structures can be electrically isolated from earthing systems via;
Other solutions, e.g. non-conductive membranes, are available as methods of electrical isolation depending on the system in question.
Insulating Flange Kits (IFK)
The kit comprises of the following;
Monolithic Isolation Joints (IJ)
The isolation joint is fabricated as a ready to install section of pipework.
The joint consists of;
Decoupling Devices
Corroconsult recommend only solid-state devices, as this eliminates the maintenance requirements and hazardous electrolytes of electrochemical polarisation cells.
Solid-state DC decoupling devices can be used for;
Incorrect Installation
An incomplete kit installation for an IFK will result in the flanged joint being electrically continuous.
Earthing / Grounding
The most common failure of installed electrical isolation is through incorrect earthing of cathodically protected structures.
This non-intrusive, above ground survey allows the operator to identify the location of coating defects (holidays).
We are pleased to announce the first uploaded animation to our YouTube channel (shown within this post).
The YouTube video represents the first instalment within a series. Its purpose is to give an introductory overview to people not familiar with the technique e.g. asset owners, operators, supervisors.
The technique is an approved ECDA (External Corrosion Direct Assessment) method as detailed in ANSI / NACE Standard Practice SP 0502-2010.
DCVG is also listed as an above-ground survey used to assess the coating condition and to locate coating defects within:
All DCVG surveys should be undertaken by competent and qualified personnel in accordance with BS EN ISO 15257:2017 - Cathodic protection - Competence levels of cathodic protection persons.
This short animation shows the technique to be utilised for a DCVG (Direct Current Voltage Gradient) survey using an analogue voltmeter and matched electrodes.
The video covers the basic methodology in identifying, centering and measuring coating defects (holidays) in the field [OL/RE Potential]
This "How To" guide is intended for asset owners, operators and supervisors that may not be familiar with the technique.
ECDA is the commonly used acronym for External Corrosion Direct Assessment. The process has been developed for buried onshore ferrous pipeline systems. ECDA was created as a process for improving pipeline safety. Its primary purpose being to prevent future external corrosion.
Whilst this post attempts to provide an overview of the ECDA process, it is imperative that it is tailored each time to address specific requirements of individual pipeline systems.
There are four main steps to the ECDA Process, these are;
The flow diagram below shows a general approach to the ECDA Process - evaluation methods may include, but are not limited to those shown here.
Pipe Related
Construction Related
Soils / Environmental
Corrosion Control
Operational Data
TR & Groundbed Functionality Checks
CIPS (Close Interval Potential Survey)
DCVG (Direct Current Voltage Gradient) Survey
Additional Information Collated
Locations for excavation shall be selected based on the information gleaned from the pre-assessment and indirect assessment procedures.
A minimum of at least one trial pit should be excavated to clarify the effectiveness of the first two procedures.
All data obtained during the survey activities is provided, generally in both graphical and tabular formats (where appropriate), as well as photographic records, etc.
Corroconsult UK Limited are pleased to announce the release of our updated website.
The new site includes expanded sections regarding our services and material data sheets as well as new client and project gallery sections.
We hope that you enjoy the new content, and will be looking to add further information over the coming months.
Corroconsult are proud to announce the renewal of their ISO and OHSAS certification following today's audit.
Following on from last years successful audit to the latest ISO standards for Quality and Environmental management systems, Corroconsult remain one of the few corrosion companies to have already been recognised with this accreditation.
Full versions of our current certificates can be found using the links below;
