Corrosion

[jmcintyre99]

Have an issue maybe some one can help with this is on water heaters in a hotel we did a couple years ago replace the nipples and dielectric unions about 9 months ago due to the same problem now it is this bad again and needs to be replaced again. Thought was due to electrolysis but all have been grounded in multiple places now and still same issue

 

[jmcintyre99]

Another pic

 

[Geofd]

you have a copper clamp on a galvi pipe the dielectric union is stopping electrolysis between the galvi pipe and the copper pipe my ground clamp is on the copper water main...

 

[jmcintyre99]

There are ground on the copper also just not shown in pic

 

[jmcintyre99]

Building is all sch80 cpvc only copper at water heaters

 

[Geofd]

There are ground on the copper also just not shown in pic

you still have 2 dissimilar metals touching...that causes electrolysis the copper and galvi cant touch each other
not sure if im describing it correctly but I think that the metals touching each other causes some kind of electrical current

 

[voletl]

Grounding has nothing to do with electrolysis. Also why did you replace the nipples with galvanized? Why not brass?

 

[jmcintyre99]

The two metals don’t touch hence the dielectric union
Brass is a nonferrous metal also just like copper and the tank of the heater is steel (ferrous metal).
But that was the thinking so far as to replace with brass this time.
I have just never seen any other ones this bad and reoccurring.