Describe "tempered water" pls. Demin water or DI water? Chloride concentration? What inhibitors are used ? Oxygen scavenger injection ? What operating temperatures ? Is closed loop expansion drum N2 blanketed?
Tempered water wont stay tempered if exchangers can leak process fluid into tempered water at shell and tube HX tube to tubesheet joints or through leaking gaskets in plate frame HX. Such leaks occur due to mechanical deficiencies in welding, diff thermal expansion, poor materials selection.
My guess for the best material is ... probably some kind of metal ... yeah ... yeah ... that's it
MadTag: "I would use metal for your heat exchanger" !!
