Orlan Super 25Kw + Akvaterm 2000 litre installation blog

[Moxi]

Based on the photo's and light surface rust the steel appears to be a mild steel, if there is a sacrificial anode it wll beed to be bolted face to face with the steel with NO rust, grease, paint or other barrier between the two metals.  This will allow a good circuit enabling the Zinc to protect the mild steel from corrossion.  On large vessels they normally allow an anode every 2 meters or so for complete protection.  I would also suggest something for the support bars holding the coils as the gasket will prevent a good electrical bond between the tank body / anode and the support bars.

Stainless 304 grade can rust if contaminated with iron particulate, eg grinding dust etc and in these instances it should be returned under warranty as the pitting corossion sets up a very localised galvanic cell leading to pin hole penetration of the stainless steel in very short order.  0.6mm per year have been recorded for this type of corrossion failure mechanism.

That said a properly protected and maintained mild steel tank can last a lifetime so please don't worry just make sure its protected to start with and the protection is maintained with anodes changed at recomended intervals.

Moxi

[noelsquibb]

Hey Moxi

where did I go wrong ?

Not a fraction of the steel and all nicely painted too.

Magnesium, titanium or zinc anodes ?

Think you have a point about the steel prong and the gasket debonding but perhaps the bolts that hold the flanges together will make the connection ?


Theres something that Akvaterm have sussed that I haven't grasped yet ......

Perhaps its just the full tank with no room for oxygen and the sacrificial anode.
Other hot water tanks seem to use expensive coatings like glass, epoxys and specialist cement based coatings though.

[billi]

thanks Fiddlers

just found out that a German stove producer  joined up with akvaterm  to supply a bundle package  solar heating  idea


i understand now more    (saw some pictures)



 thanksBilli

[knighty]

the inside of the tank looks galvanised to me.... ?

[Moxi]

Noel,

Sorry for the delay I'll read your thread over the weekend and have a think before replying in actual thread.

Moxi