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Valve disc corrosion - Possibly MIC?

Valve disc corrosion - Possibly MIC?

Valve disc corrosion - Possibly MIC?

(OP)
Dear all,

Does this look like MIC corrosion? any ideas?
This was closed all the time. Nothing was flowing trough it.
Only at one spot as you can see in pic 1 I see this smooth corroded surface. The medium was water at room temperature.

Herc

RE: Valve disc corrosion - Possibly MIC?

Based on the last photograph and the concentric rings of oxide streaks, it could be MIC damage. This could have been initally caused by underdeposit corrosion if this valve is closed and contained stagnant water. How clean was the water?

RE: Valve disc corrosion - Possibly MIC?

(OP)
This was regular stagnant municipal water with no treatment.

RE: Valve disc corrosion - Possibly MIC?

Hard to tell from a photograph that it is MIC or not. Just looks like under-deposit corrosion. Can't see any obvious signs of slime's unless they have all be cleaned off. MIC loves ductile iron in stagnant conditions and causes an accelerate rate of corrosion attack. You would need to do Biological testing if you want to confirm a diagnosis of MIC not just EDS.

RE: Valve disc corrosion - Possibly MIC?

This appears to be MIC caused by anaerobic bacteria that will reducing the sulfate ion to sulfur. The end result for the bacteria is a sulfuric acid solution. Would also expect some black staining of the pipe. The piping material may be flaking off in layers, but this is hard to see in the pictures.

I witnessed this with a deep well where the carbon steel bolts of a well pump were eaten away in about 2 years.

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