03 / CATHODIC PROTECTION
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. Cathodic protection (ระบบป้องกันการกัดกร่อน) ใช้ป้องกันถัง ท่อ และโครงสร้างเหล็กในน้ำทะเล ดิน และคอนกรีตเสริมเหล็ก.
Galvanic vs. impressed current — comparison
| Aspect | Galvanic (Sacrificial) | Impressed Current (ICCP) |
|---|---|---|
| Power source | Self-powered by the anode alloy's natural potential — no external supply. | Driven by an external DC supply (transformer rectifier). |
| Typical anode products | Magnesium · Aluminium · Zinc galvanic anodes. | MMO (titanium) · High-Silicon Cast Iron · Flexible Linear anodes. |
| Driving voltage | Low and fixed by the alloy; best in low-resistivity electrolytes. | Adjustable at the rectifier; suits high-resistivity and high-demand conditions. |
| Current output | Limited and self-regulating. | High and controllable across large areas. |
| Design life | Governed by anode mass; sized for the required service period. | Long service life with very low anode consumption (inert anodes). |
| Maintenance | Minimal — no power, few moving parts. | Requires power supply and periodic monitoring. |
| Best suited to | Marine structures, ship hulls, buried tanks, short or well-coated pipelines. | 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.
GALVANIC · NO EXTERNAL POWER
Sacrificial Anodes
Self-powered magnesium, aluminium, zinc and pure-iron anodes. For buried pipelines and tanks, marine structures and ship hulls.
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IMPRESSED CURRENT · POWERED
ICCP Anodes
Inert MMO, high-silicon cast iron and flexible linear anodes powered by transformer rectifiers — for long pipelines, tank bottoms and large assets.
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EQUIPMENT & MATERIALS · NON-ANODE
CP Equipment & Materials
Transformer rectifiers, reference electrodes, test stations, cables, tapes and AC mitigation — the power, monitoring and connection products that complete a system.
View range →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.
SACRIFICIAL · MARINE VESSELS
Boat & Ship Anodes
Hull, shaft, rudder and trim-tab anodes for pleasure and commercial craft — the same zinc, aluminium and magnesium sacrificial anodes in ready-to-fit form, chosen by water type.
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SACRIFICIAL · HEAT-TRANSFER EQUIPMENT
Condenser Anodes
Zinc, magnesium and pure-iron anodes for condensers, water boxes, cooling systems and tank interiors — matched to the system metals to protect from internal corrosion.
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SACRIFICIAL / POWERED · TANKS
Water-Heater & Tank Anodes
Sacrificial (magnesium / aluminium) and powered anode rods that extend the life of water heaters, cylinders and small tanks — supplied in quantity to installers and OEMs.
View product →Frequently Asked Questions
What is cathodic protection (cathodic protection คือ)?
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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