Cathodic Protection

Corrosion-control products for marine, offshore, pipeline and industrial assets — sacrificial anodes, impressed current (ICCP) systems and materials, supplied to recognised international standards.

What is cathodic protection?

Cathodic protection (CP) controls corrosion by making a metal structure the cathode of an electrochemical cell, transferring metal loss to a dedicated anode. It is used wherever steel and other metals are permanently exposed to seawater, soil or other electrolytes. PCX supplies the anodes, reference electrodes, rectifiers, test stations, cables and accessories used within cathodic protection projects, sourced from qualified international manufacturers and supplied to project specification.

Galvanic vs. impressed current — comparison

Aspect
Power source
Galvanic (Sacrificial)
Self-powered by the anode alloy's natural potential — no external supply.
Impressed Current (ICCP)
Driven by an external DC supply (transformer rectifier).
Aspect
Typical anode products
Galvanic (Sacrificial)
Magnesium · Aluminium · Zinc galvanic anodes.
Impressed Current (ICCP)
MMO (titanium) · High-Silicon Cast Iron · Flexible Linear anodes.
Aspect
Driving voltage
Galvanic (Sacrificial)
Low and fixed by the alloy; best in low-resistivity electrolytes.
Impressed Current (ICCP)
Adjustable at the rectifier; suits high-resistivity and high-demand conditions.
Aspect
Current output
Galvanic (Sacrificial)
Limited and self-regulating.
Impressed Current (ICCP)
High and controllable across large areas.
Aspect
Design life
Galvanic (Sacrificial)
Governed by anode mass; sized for the required service period.
Impressed Current (ICCP)
Long service life with very low anode consumption (inert anodes).
Aspect
Maintenance
Galvanic (Sacrificial)
Minimal — no power, few moving parts.
Impressed Current (ICCP)
Requires power supply and periodic monitoring.
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Best suited to
Galvanic (Sacrificial)
Marine structures, ship hulls, buried tanks, short or well-coated pipelines.
Impressed Current (ICCP)
Long pipelines, tank bottoms, platforms, large or high-resistivity assets.

Product families

Anodes divide into two families — sacrificial (no external power) and impressed current (powered) — supported by the non-anode equipment and materials that complete a system.

Where our anodes are used

The same sacrificial and impressed-current anodes are also supplied as ready-to-fit products for specific equipment — from ships and heat exchangers to water heaters and tanks. These are the anodes above in finished form, matched to the application.

Frequently Asked Questions

What is cathodic protection?

Cathodic protection (CP) controls the corrosion of a metal surface by making it the cathode of an electrochemical cell — shifting its potential so that metal loss is transferred to a dedicated anode instead of the protected structure. It is applied wherever metal is permanently exposed to seawater, soil or another electrolyte, such as pipelines, storage tanks, marine structures and reinforced concrete.

Sacrificial (galvanic) or impressed current (ICCP) — what is the difference?

Galvanic protection uses an active alloy — magnesium, aluminium or zinc — that corrodes preferentially to drive protective current, with no external power. Impressed-current (ICCP) protection uses a transformer rectifier to drive current through inert anodes such as MMO, high-silicon cast iron or flexible linear anodes, giving adjustable output and long service life. Galvanic suits marine structures, buried tanks and short or well-coated pipelines; ICCP suits long pipelines, tank bottoms and large or high-resistivity assets. See the comparison table above.

Which anode material should I use?

For buried pipelines and tanks in soil or freshwater, magnesium provides the high driving voltage required. For seawater and offshore service, aluminium (Al-Zn-In) gives the highest capacity and zinc gives stable, well-understood performance. For impressed-current systems, MMO titanium is the modern default, with high-silicon cast iron for cost-effective groundbeds. Send us the structure and environment and we will recommend the material.

Do you supply the complete cathodic protection system?

PCX supplies the anodes, reference electrodes, rectifiers, test stations, cables, backfill and accessories used within cathodic protection projects, sourced from qualified international manufacturers and supplied to your project specification. We do not carry out the corrosion-engineering design ourselves, but for straightforward requirements our partners can assist with anode sizing from your structure and environment data.

Do you supply cathodic protection products in Thailand, and how do I get a quotation?

Yes. PCX supplies cathodic protection anodes and materials across Thailand. When requesting a quotation, please specify the anode type or CP product, the structure and environment (seawater, soil or concrete), the design life, and the current demand or structure dimensions — and we will return a quotation.

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