Steam Boiler Question

[BoilerDude]

I was wondering if I installed a sacrificial anode in a boiler feed tank if that would help a client that does not believe in water treatment.
Thanks

 

[TBP]

Does your client have a system in which 100% of the condensate is returned? If he does, then maybe he's OK. However, if he DOESN'T have such a system, then he thinks what - that oxygen pitting and waterside fouling that results in 700*F stack temps are "normal"?

 

[BoilerDude]

The system is supposed to 100% return. It is a low pressure steam system >15psi and he is having some pitting inside the boiler and condensate lines
Thanks

 

[TBP]

Is the boiler only pitting at the water line? If it is, then that's likely from sitting out of service for extended periods, with water in the boiler. The upper layer of boiler water absorbs oxygen from the atmosphere, and that causes the pitting. If the steam isn't required for a couple of weeks or longer, he should probably dump the water, open the manhole/handholes, flush the boiler out with a hose, and let it sit open and dry. If it's pitting kind of all over, then that's likely from makeup water that's full of oxygen being fed to the boiler. That means that some condensate isn't making it back - either at all, or that the condensate lines are old & clogged, slowing the condensate's return to the point where the make-up kicks in.

Pitting in the return lines is usually due to vacuum breakers operating at the end of the steam cycle, admitting air. You need this to happen though, condensate won't drain properly, and that causes another whole range of problems. If the return line corrosion appears as general wasting below the normal operating line (about half full of condensate), then that's pH related. Again, make-up water is the culprit. Alkalinity in the make-up water breaks down into carbon dioxide in the boiler, and this gets carried out with the steam. It dissolves in the condensate, and drops the pH, resulting in general metal loss.

 

[unclesyd]

The anode material is going to end up in the boiler.

 

[leo392003]

CHECK PTC 4

 

[GenB]

Anode is perfectly fine for lp boiler but some chemical-boiler treatment shuold be added to the water to keep the sys neutral to corrossion.
consult a competent mechanical or boiler treatment company for the proper treatment.
ER