Anyone use cathodic protection in thermal storage?

[Lance Stronk]

I have a thermal storage 620 gal for my Tarm boiler that I need to replace coils as the coils have developed pinholes - presumable from corrosion, more likely from electrolysis action.
Anyone use sacrificial anodes in their tanks? If so, how is it set up?
This tank is not a closed system - it is open to atmosphere and has submerged coils from boiler. It is an insulated tank with a rubber 'pond liner'. Sunmaxx Solar sold me the tank in 2014 and they didn't have a suggestion.
Thanks!

 

[Whitenuckler]

I have a thermal storage 620 gal for my Tarm boiler that I need to replace coils as the coils have developed pinholes - presumable from corrosion, more likely from electrolysis action.
Anyone use sacrificial anodes in their tanks? If so, how is it set up?
This tank is not a closed system - it is open to atmosphere and has submerged coils from boiler. It is an insulated tank with a rubber 'pond liner'. Sunmaxx Solar sold me the tank in 2014 and they didn't have a suggestion.
Thanks!

I'm not sure what is required, but you should try a rod right away. Maybe one for a hot water tank?

Sacrificial anodes for storage tanks

External protection Due to limited lifespan, external cathodic protection with sacrificial anodes are normally arranged for smaller tanks and as temporary protection. Anodes Cathodic protection of underground storage tanks may be arranged by installation of magnesium anodes. The high grade...

cathwell.com

 

[hobbyheater]

I have a thermal storage 620 gal for my Tarm boiler that I need to replace coils as the coils have developed pinholes - presumable from corrosion, more likely from electrolysis action.
Anyone use sacrificial anodes in their tanks? If so, how is it set up?
This tank is not a closed system - it is open to atmosphere and has submerged coils from boiler. It is an insulated tank with a rubber 'pond liner'. Sunmaxx Solar sold me the tank in 2014 and they didn't have a suggestion.
Thanks!

Do you have more than two dissimilar metals in your tank ?

 

[EatenByLimestone]

Do you have an inspection hole or capped lid? Drop an anode down on a string or wire.

 

[Whitenuckler]

Do you have more than two dissimilar metals in your tank ?

I'm not sure how this relates, but I was watching a show on Utube about how they do maintenance on battle ships ie New Jersey.
I remember a show where the dock guys ordered new magnesium blocks for the hull. They went outside in the water. From what I understand, they are required or the steel hull will get eaten away. They use ultrasound to measure the hull thickness to test for this corrosion. If you have a steel tank with liquid inside, perhaps that's all you need for corrosion. I know other ships have some sort of electrical cathodic protection. Very specialized area, a blend of electrical and chemical engineering.

 

[Lance Stronk]

Do you have more than two dissimilar metals in your tank ?

Yes - the coils are stainless steel. There is a copper in the tank that forms the support for the coils and lid.
The tank itself is lined with a rubber 'pond' liner so it is not conductive. Fittings between coil sections and at coil to copper interfaces are brass.

 

[Lance Stronk]

Do you have an inspection hole or capped lid? Drop an anode down on a string or wire.

Yes - there is an inspection hole/vent.
I am guessing I need to connect the anode to my earth ground/service ground?

 

[Whitenuckler]

Yes - there is an inspection hole/vent.
I am guessing I need to connect the anode to my earth ground/service ground?

If I remember changing the anode on my hot water tank, there was a choice between aluminum and magnesium and
it screwed into the tank steel so grounded.