Routine Monitoring / Maintenance & Repair

Periodic Surveys

Periodic cathodic protection surveys assess the ongoing condition and performance of a CP system at planned intervals. They confirm that the protected asset continues to meet the required protection criteria and allow deterioration or system faults to be identified before corrosion damage occurs.

Survey activities may include:

• Structure-to-electrolyte potential measurements
• Polarised / instant OFF potential measurement
• Inspection of transformer rectifiers and system output
• Testing of sacrificial anodes and impressed current groundbeds
• Inspection of test posts, junction boxes, cables and connections
• Isolation joint and insulating flange kit testing
• Checking interference bonds, decouplers/polarisation cells and surge-protection devices
• Assessment of reference electrodes, coupons and corrosion monitoring probes
• Investigation of stray-current or third-party interaction
• Comparison with previous survey results and baseline data

The survey frequency is determined by the asset type, CP system, operating environment, regulatory requirements and historical performance. Additional testing may be recommended following construction work, system modifications, equipment failure or significant changes near the protected structure.

Results are assessed against the applicable cathodic protection criteria and compared with earlier data to identify trends or developing faults. Where deficiencies are found, recommendations may include output adjustment, repairs, further investigation or a more detailed specialist survey.

A comprehensive report records the inspection findings, measurements, compliance status, identified defects and prioritised recommendations, supporting maintenance planning and the continued integrity of the protected asset.

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Remote Monitoring System Testing and Repair

Remote monitoring system testing and repair ensures that cathodic protection monitoring equipment continues to collect and transmit accurate system performance data.

Testing may include:

• Inspection of remote monitoring units, enclosures and connections
• Verification of reported readings locally; check transformer-rectifier voltage and current outputs and potential readings against the reported data
• Testing of the permanent test equipment such as reference electrodes and coupons
• Verification of communications through cellular, satellite, radio or network connections
• Inspection of antennas, SIM cards, modems and communication cables
• Testing batteries, solar panels, wind generators, chargers and power supplies
• Confirmation of alarms, reporting intervals and data upload functions
• Review of timestamps, GPS information and stored historical data
• Testing remote switching or control functions where fitted

Fault investigation may identify defective test equipment, damaged/loose wiring, failed or turned off power supplies, communication/signal problems, incorrect configuration, water ingress or vandalism. Repairs can include replacing components, restoring cable connections, resealing enclosures, updating settings and recommissioning the monitoring unit.

Following repair, measurements are verified against calibrated test equipment, communications are confirmed and alarm or control functions are tested. The system is then returned to service with its correct configuration and reporting schedule.

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Electrical Resistance Probe Testing

Electrical resistance probe testing measures the corrosion lose by monitoring changes in the electrical resistance of a specially designed metallic sensing element. As the element corrodes and loses cross-sectional area, its electrical resistance increases, allowing cumulative metal loss, thus the corrosion rate to be calculated.

Testing activities may include:

• Inspection of the probe cabling, access fittings and the monitoring/datalogging equipment
• Recording and downloading the probe measurements
• Verification of instrument operation and configuration
• Checking probe continuity, reference elements and electrical connections
• Comparison with baseline and previous readings
• Calculation of cumulative metal loss and corrosion rate
• Assessment of changes in corrosion activity over time
• Investigation of unstable, abnormal or non-responsive readings
• Replacement of damaged, exhausted or defective probes

Electrical resistance probes can provide corrosion data without requiring fluid conductivity and may be used in pipelines, tanks, process systems, soil, water and atmospheric environments. Permanently installed probes also allow long-term monitoring and can be connected to dataloggers or remote monitoring systems.

Results are analysed alongside operating conditions, cathodic protection data and previous measurements to identify trends or periods of increased corrosion activity. As the probe represents conditions only at its installed location, findings should be considered with other inspection and monitoring information.

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Reactive and proactive maintenance

Reactive and proactive maintenance services help ensure that cathodic protection systems remain reliable, continually operate effectively and are compliant throughout their operating life.

Proactive maintenance is planned using routine inspections, monitoring data, historical performance and equipment condition. Its purpose is to identify and correct developing problems before they result in CP failure or increased corrosion risk. Activities may include:

• Planned inspection and servicing of transformer rectifiers and bonds
• Checking system outputs and protection potentials
• Testing permanent test equipment such as reference electrodes, coupons and monitoring probes
• Inspection of cables, test posts, junction boxes and connections
• Testing isolation joints, flanges and anode groundbeds
• Cleaning, tightening and protecting electrical connections
• Replacement of ageing or deteriorating components
• Analysis of performance trends and recurring faults

Reactive maintenance is undertaken following a system alarm, abnormal survey reading, equipment failure, accidental damage or loss of protection. It typically involves fault diagnosis, emergency attendance, repair or replacement of defective equipment and recommissioning of the system.

Following maintenance, electrical and cathodic protection measurements are completed to confirm that the system has been restored to the required operating condition. Where an immediate permanent repair is not possible, temporary measures may be implemented to maintain protection until the full repair can be completed.

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Ground Control - Clearance

Ground control and clearance services maintain safe, reliable access to cathodic protection equipment and monitoring locations. Vegetation, accumulated soil, debris and surface deterioration can restrict access, conceal defects and prevent effective inspection or maintenance.

Activities may include:

• Vegetation and undergrowth clearance around test facilities and markers
• Clearing access to transformer rectifiers, anode groundbeds and junction boxes
• Removal of accumulated soil, debris and obstructions
• Locating buried or overgrown CP monitoring facilities
• Reinstating safe pedestrian access to equipment
• Exposing test-post bases and cable-entry points for inspection
• Cleaning concrete bases, enclosures and identification markers
• Clearing/removing insect nests/infestation, such as ant and wasp nests
• Minor ground levelling and reinstatement
• Identifying erosion, flooding, subsidence or third-party disturbance
• Recording damaged, missing or inaccessible equipment

Work is planned with consideration for buried services, landowner requirements, environmental restrictions and site-specific safety controls. Care is taken to avoid damaging CP cables, anodes, pipelines or other underground infrastructure.

Following clearance, the equipment can be visually inspected and tested, with any defects or access issues documented. Recommendations may include further civil works, drainage improvements, replacement markers, fencing repairs or more frequent vegetation management.

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Client Customised Survey

Client specific or customised surveys can be developed to address specific corrosion, cathodic protection or asset-integrity requirements that may not be fully covered by a standard survey methodology.

Working closely with the client, the survey scope, testing procedures and reporting format can be tailored to the asset, site conditions, operating constraints and project objectives. Customised surveys may combine several techniques, including:

• Structure-to-electrolyte potential measurements during operation and non-operation periods
• CIPS, DCVG or ACVG surveys as described beforehand
• Current attenuation and current-mapping surveys
• Stray-current and third-party interaction testing
• Current drain or current-injection testing
• Isolation, continuity and interference-bond testing
• Soil resistivity and environmental testing
• Long-term data logging and trend analysis
• Cathodic protection system performance and fault investigations

Surveys can be designed for all metallic structures, most commonly for pipelines, tanks, marine structures, industrial facilities and other buried, embedded or immersed assets. Testing can also be adapted to accommodate restricted access, live operational sites, unusual configurations or specific company standards.

Such tailored surveys will provide the client with the information required to support design decisions, maintenance planning, fault resolution and long-term asset integrity management.

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