Remove harmful sulfur compounds from transformer oil

Corrosive sulfur removal

We remove corrosive sulfur and DBDS from transformer oil on site, before they attack the windings and insulation. Corrosive sulfur compounds react with copper to form copper sulfide, which deposits in the paper insulation and degrades dielectric strength — a known cause of transformer failure. We treat the oil on the energized transformer and bring it back to non-corrosive, verified against IEC 62535.

Standards & compliance: IEC 62697-1IEC 62535

What we do

Corrosive sulfur — including dibenzyl disulfide (DBDS) and elemental sulfur (S₈) — is a chemical threat distinct from moisture or particles. It forms copper sulfide on the windings and migrates into the paper insulation, where it lowers dielectric strength and can lead to failure. Standard filtration and drying do not remove it.

We bring an Ekofluid plant to your site and run the oil through a process that removes the corrosive sulfur compounds and the reactive sulfur species behind them. The work is done on the energized transformer, sealed and automatic, so the asset stays in service throughout. The oil leaves the process non-corrosive and verified against the standard.

How it works

  1. Test

    We sample the oil and test for corrosive sulfur and DBDS (IEC 62535), confirming the problem and its severity.

  2. Mobilize

    The plant is delivered to your site and connected to the energized transformer.

  3. Treat

    The oil circulates through the process; corrosive sulfur, DBDS, and reactive sulfur are removed below detectable levels.

  4. Verify

    The treated oil is re-tested against IEC 62535 and the corrosive-sulfur result documented.

  5. Complete

    The transformer stays energized throughout; the oil is non-corrosive when the plant disconnects.

What you get

Corrosive sulfur neutralized at the source, with results documented against the standard:

Corrosive sulfur (IEC 62535)
non-corrosive
DBDS
< 5 mg/kg
Elemental sulfur (S₈)
removed

The copper-sulfide risk to your windings and insulation is removed without an outage and without replacing the oil, protecting the transformer's insulation life.

Remove corrosive sulfur from your transformer oil

Tell us about your transformers and their oil condition. Our engineers will confirm whether corrosive sulfur removal is the right service and plan it around your assets.