Marine and Offshore Heat Exchanger Protection
Spray is different from airborne salt
Near the shore, salt reaches coils as a fine aerosol that settles slowly. On a ship’s deck or an offshore platform, coils are hit by droplets of seawater and wind-driven spray, and salt builds up on the fins as a crust. Chloride levels are far higher, and the coil may never fully dry.
What coating can and cannot do
A coating keeps seawater off the metal for as long as the film stays intact. Under constant spray, any damaged area — a bent fin, a scratch at installation — becomes the starting point for corrosion. Coating extends coil life; it does not replace coil material selection, shielding or regular fresh-water washing.
ISO 9223 corrosivity category
Typical category for this environment: C5–CX.
- C1Very low
- C2Low
- C3Medium
- C4High
- C5Very high
- CXExtreme
Recommended protection by exposure
| Condition | ISO 9223 | Recommended system | Note |
|---|---|---|---|
| Quayside and port buildings, sheltered from spray | C5 | PG-S1 Polysiloxane sol-gel | Dip before shipment; inspect and clean on a fixed schedule. |
| Open deck or platform, direct spray | CX | PG-C Air-dry 2K | Thicker film; review fin density and heat-transfer margin first. |
| Enclosed machinery spaces with sea-air intake | C5 | PG-S1 Polysiloxane sol-gel | Salt enters with the ventilation air. |
Not sure which category your site falls into?
Enter distance from the sea, humidity and nearby industry to get an estimated ISO 9223 category.
Related
- CoatingsAir-Dry Two-Component Chemical-Resistant Coating
- EquipmentCopper Tube, Aluminium Fin Coil Protection
- EnvironmentsCoastal HVAC Corrosion by Distance from the Sea
- MarketsCoil Coating for HVAC Projects in the Pacific Islands
- ComparisonsCoated Cu-Al Coils vs Copper-Fin Coils
- GuidesHow Long Does Coil Coating Last in a C5 Environment?
Also see
- CoatingsWaterborne Polysiloxane (Sol-Gel) Coil Coating
- EquipmentCondenser Coil Anti-Corrosion Coating
- EnvironmentsISO 9223 Corrosivity Categories (C1–CX) for HVAC
- ComparisonsThin-Film vs Thick-Film Coil Coatings
- GuidesCan Existing Corroded Coils Be Recoated?
- CoatingsPre-Coated Fin Stock (Blue Fin, Gold Fin)
- EquipmentAir-Cooled Chiller Coil Protection
Is coating enough for coils on an open deck?
Coating slows corrosion but does not stop it under direct spray. Combine it with a suitable coil material, shielding where possible and a washing and inspection schedule.
Do marine projects need a specific standard?
Ship and offshore projects often have their own owner or class specifications. Send them with the enquiry and the coating will be reviewed against them.
Tell us the equipment, the site and the destination port. We reply within 24 hours.