Descaling

Hello CHAUDHARI

You say the penstocks are choked with lime, which I understand as Calcium Carbonate CaCO₃.

It is entirely possible the location is in the Himalayan area, and the water will be full of heavy metals and sulphates, and the "lime" is not actually lime (Calcium Carbonate CaCO₃) .

Have you had the "lime" analysed to see exactly what it is, yet?

It would be helpful if you could respond with answers to the following specifics:

1. Please advise if your "lime" is as above (Calcium Carbonate CaCO₃)
2. Is the "lime" as a very hard scale lining, built up over a period? - If so, advise how long the build-up has taken to the present stage.
3. Is the "lime" a powdery sediment?
4. What is the material the penstocks are made of - cast iron, steel, other?
5. Are the penstocks lined with epoxy paint, or otherwise coated internally?
6. Your water supply - If you advise location and river, it would assist with diagnosis

In the absence of the above details asked for, and assuming that the choking substance is actually lime (Calcium Carbonate CaCO₃), and the penstocks would not be damaged by it's use, Sulphuric Acid from the top would do the job.

Users of the Acid would need to have proper instruction in the use of the acid.

Great care would be needed to not spill the acid or the reacted compounds.

Ensure no Acid or reacted compounds enter a stream or watercourse, or ground-water aquifer.

Reply here, with

Kind Regards....