Pole Transformer Tank Rust.

They are quite thick - few mm, they have to be for the weight of the oil and the transformer.


This ABB spec suggests a minimum of at least 2 or 2.5mm for stainless or mild steel respectively.
DNO specs may add additional things, like a sight glass window that allows oil to be checked with binoculars.


so how fast will it corrode. Well it all depends on the environment. 

If we said C3 medium, clean air periodic light dew condensation then 25-50um per year

1mm = 1000um ,so 1mm every 20 -40 years.

I suspect the DNO inspect it by then.

But if it was  in a very high corrosion environment, like by the seaside or in the chlorinated atmosphere of a swimming pool vent, then it could go ten times faster..

You can also see why galvanizing with zinc helps, and how corrosion of the steels really takes off once the protective coat of zinc is depleted. (typical galvanising is 85um nominal - UK map typical corrosion estimator by postcode)




Mike

They are quite thick - few mm, they have to be for the weight of the oil and the transformer.


This ABB spec suggests a minimum of at least 2 or 2.5mm for stainless or mild steel respectively.
DNO specs may add additional things, like a sight glass window that allows oil to be checked with binoculars.


so how fast will it corrode. Well it all depends on the environment. 

If we said C3 medium, clean air periodic light dew condensation then 25-50um per year

1mm = 1000um ,so 1mm every 20 -40 years.

I suspect the DNO inspect it by then.

But if it was  in a very high corrosion environment, like by the seaside or in the chlorinated atmosphere of a swimming pool vent, then it could go ten times faster..

You can also see why galvanizing with zinc helps, and how corrosion of the steels really takes off once the protective coat of zinc is depleted. (typical galvanising is 85um nominal - UK map typical corrosion estimator by postcode)




Mike