Acceptable chloride levels for submersed ductile iron

[Hercules28]

Dear all,

I have some issues with some cast iron parts that are submersed in water. The water comes from a treatment facility but upon water testing I found high levels of chlorides in the range of 72mg/L.

I also have
Calcium 120mg/L
Fe 8 mg/L
Mg 12mg/L
Si 14mg/L
Na 28mg/L


Water is flowing...don't know the speeds. Any ideas? The part end corroded like 1/4 inch in 2 months.

 

[TomDOT]

Salty, moving, oxygenated water is an excellent method for rapidly corroding iron or mild steel.

Some basic choices: Coating, cathodic protection or choosing a corrosion-resistant material for your parts.

 

[bimr]

72 mg/l is not a high concentration of chloride. As TomDOT points out, the corrosion is due to oxygenated water.

Wetted components at treatment facilities are normally fabricated of 304 stainless steel.