When equipment is in immersion service, choosing the right internal coating isn’t just about picking a material off a spec sheet. It’s about understanding the real-world conditions your coating will face—and in many plants, those conditions are tougher than they first appear.
At Curran International, we help clients account for every factor, from fluid chemistry and operating temperature to more subtle (and often overlooked) failure mechanisms.
Beyond the Basics: Factors That Can Ruin a Coating
When specifying a coating, most engineers consider:
• Operating temperature
• Fluid exposure
• Insulation requirements
But that’s only the start. Two less obvious threats—steam cycling and cold-wall failure—are behind many premature coating breakdowns.
1. Steam Cycling
In many refineries and petrochemical facilities, utility steam is used for maintenance, often at around 150 PSIG—which translates to roughly 365°F.
Even if steam isn’t in direct contact with the coated surface, heat conduction through steel can blister coatings that aren’t rated for that level of exposure.
2. Cold-Wall Failure
This less-discussed failure mechanism occurs when:
• One side of the coated substrate is in hot immersion service
• The opposite side is uninsulated or in cold immersion service
A temperature differential of as little as 70°F can cause blistering on the hot side. Equipment like two-pass exchanger channels and condenser water boxes are especially vulnerable.
Why Manufacturer Data Sheets Aren’t the Whole Story
Many coating data sheets list dry temperature resistance—but for immersion service, that’s not enough.
You should always:
• Confirm wet/immersion temperature limits directly with the manufacturer
• Consider residual moisture (such as latent water in unopened cooling water exchangers during steam-out)
• Check for cold-wall performance data, such as results from Atlas Cell testing
Curran’s Proven Immersion Coatings
We put every Curran coating through rigorous client field trials, third-party lab testing, and our own in-house qualification processes.
Our immersion-rated coatings include:
• Curran 1000R — immersion resistance to 365°F
• Curran 1200 — immersion resistance to 365°F
• Curran 1500 — immersion resistance to 365°F and passed cold-wall testing in a pressurized Atlas Cell at 365°F
Choosing the Right Coating is About Prevention
Coating failure in immersion service isn’t just a maintenance headache—it can mean unscheduled outages, expensive repairs, and lost production time. The right choice upfront prevents all of that.
📧 Ed Deely — edeely@curranintl.com
📞 (281) 339-9993
