Will iron rich water attack copper & s/steel?

[garyb]

Hi All

We have been suppling bare pipe evaporators (100-500kW) for vegetable hydro-coolers for a local manufactuer that sells them all over the world (from New Zealand) as a part of their vegetable handling systems We are about to contruct the latest evaporator which is going to the Toronto area and have been told the the water to be used is from a well that is "high in iron". My question is will this set up a galvanic corrosion cell between the iron in water solution, the copper tubes and the stainless steel basin. The copper does not touch the stainless anywhere because of nylon packers and bushes. They stainless basin is about 8m long with about 2000m of 16mm tube. Water is pumped over the evaporator and falls down through the carrots n a conveyor underneath.

Has anyone done anything like this or had problems with iron rich water?

I guess the obvious answer is to condition the incoming water but I would like to know the implications of this failing to work.

Sorry about the metric units!
Best Regards
Gary

[Johnny Rod]

I don't think there'd be a problem as between iron, stainless and copper, iron is the easiest to oxidise. In solution it's already oxidised so won't want to go back.

That said, the water must be high in iron for a reason, and there will be something else with it - sulphate, chloride, nitrate, etc. - which could cause problems. Chlorides are very corrosive to stainless, for example. Additionally other metals like copper dissolved in the water can help catalyse corrosion. I would suggest getting a water sample and getting it analysed by someone e.g. local water board, and getting their advice.