Citric acid passivation for ss tankless?

[BenT123]

Would it make sense to run a citric acid solution for 2-3 hours (with octa/decyl glucoside as surfactant) to passivate the stainless steel heat exchanger?

 

[Fitter30]

Would it make sense to run a citric acid solution for 2-3 hours (with octa/decyl glucoside as surfactant) to passivate the stainless steel heat exchanger?

Asking for a combi water heater? I've only seen it done on process equipment. Never seen it done on a plate and frame hx used for condenser, chilled or heated water.

 

[Sponsor]

 

[BenT123]

Yes, residential tankless water heater. After giving it some more thought, I figure that passivation would be beneficial from the burner side and not much from the water supply side.

 

[Fitter30]

Yes, residential tankless water heater. After giving it some more thought, I figure that passivation would be beneficial from the burner side and not much from the water supply side.

Your only treating waterside. Burner can be 3500°+. The hx water is moving fast. I've seen hx twisted like a pretzel in a copper fin hx from low flow , scaled or flow switch isn't fast enough. Passivation burner side isn't touched. Plate and frame both sides can be treated or shell and tube. Hx compromised more than 1/2 the time it's cheaper to replace whole unit than repair because of labor.