Transformer Radiator Leak Sealing

The challenge

A transformer radiator bank was weeping oil from corrosion pinholes along the fin headers and the welded seams. The seep left oil stains running down the radiators and a slow loss that maintenance kept chasing from one spot to the next. Weeping oil from a transformer is more than a housekeeping problem. It signals that the steel is thinning, it can spread to the next seam as the pinholing works along the header, and the staining and drips raise both an environmental and a reliability concern for the unit. Draining and replacing radiators is costly and pulls the transformer out of service, so the bank needed a repair that worked on the wetted steel and held.

The Belzona approach

The method works on the wetted steel rather than fighting it. First the weeping area is cleaned and the active seep is stopped so the surface can hold a repair. An oil-tolerant composite that bonds to oil-contaminated steel then rebuilds the corroded header and the affected seams, returning a sound profile where the pinholes were. Once the leak is sealed and the metal is rebuilt, a corrosion coating carries across the radiator surfaces so the pinholing does not simply march on to the next seam. The result seals the leak and protects the bank without draining the radiators and swapping them out.

1. Assess the bankThe weeping pinholes are traced along the fin headers and seams, confirming where the steel has thinned so the repair covers the active loss, not just the surface stain.
2. Surface preparationThe oily, weeping area is cleaned and the wetted steel prepared so the composite has a sound surface to grip on the contaminated metal.
3. Stop the seep and rebuildThe active seep is stopped, then an oil-tolerant composite rebuilds the corroded header and seams, bonding to the wetted steel and returning the lost profile.
4. Coat the radiator surfacesA corrosion coating carries across the radiator surfaces so the pinholing is held in check and does not spread to the next seam.
5. Return to serviceThe repair cures and the sealed, coated bank is inspected before it goes back into service, with no radiators drained or replaced.