Heat Exchanger Water Box Protection
Blasting, metal rebuild, and a barrier coating restore a corroded exchanger water box and tube sheet in cooling-water service.
What was failing
In refinery cooling-water service, a shell-and-tube exchanger water box and tube sheet take constant chemical and erosive attack. The metal thins, and corrosion concentrates at the tube-to-tubesheet interface where galvanic attack can take hold. Left unchecked, this loss of wall threatens the integrity of the exchanger and forces unplanned repairs. That pulls a unit out of the cooling train and shortens the interval between turnarounds.
How AAS approaches it
We blast the water box and tube sheet internals back to clean, sound metal. We rebuild the lost and eroded sections with Belzona 1000 Series composites to restore the original profile. Then we apply a Belzona 5000 Series barrier coating system across the internals to separate the metal from the cooling water. Where the exchanger runs cathodic protection, we integrate the coating with the existing system so the two work together.
Assess and isolate
We inspect the water box and tube sheet, map the metal loss, and confirm the unit is isolated and ready for in-situ or shop work.
Surface preparation
We abrasive blast the internals to a clean, anchored profile and remove corrosion product from around the tube ends.
Rebuild lost metal
We rebuild eroded and thinned areas with 1000 Series composites to bring the surface back to profile.
Apply barrier coating
We coat the water box and tube sheet with a 5000 Series protective system and tie it into any existing cathodic protection.
Cure and return to service
We confirm cure and coating continuity, then hand the exchanger back for reassembly and return to the cooling train.
The result
From the job
Repair and protection work of this kind, performed by AAS crews across Louisiana.
Capabilities used here
Where this work happens
Other projects
Storage Tank Floor Reclamation
Corroded aboveground tank floor rebuilt and lined back to immersion service without cutting out plate.
View project
Centrifugal Pump Rebuild & Efficiency Restoration
Cold-rebuilding an eroded pump casing and lining it to restore clearances, no new casting required.
View project
Live Pipe Leak Seal & Composite Wrap
Live leak sealed and a degraded process line reinforced with an engineered composite wrap, no welding and often no shutdown.
View project
Wastewater Clarifier & Concrete Structure Relining
Spalled, rebar-exposed concrete clarifier rebuilt and relined for continued immersion service.
View project
Chute & Hopper Erosion Lining
Worn chutes, hoppers, and slurry pumps rebuilt and lined with impact- or abrasion-resistant systems matched to the wear.
View projectHave equipment that needs to stay in service?
Tell us what is failing. We respond quickly, and we offer 24-hour on-call service.