SS is preferable choice of material for DM water mainly due to near neutral pH condition. Further there is a possibility of Na slippage during ionisation process. For some application particularly for producing steam iron contamination by corrosion products are not tolerated. Hence,it is safe to use SS metallurgy for DM Water for for producing steam . The corrosion rate will be very minimal in case of SS.Choice is depends on which service you want to use. regards,

Generally SS 304 piping is used for DM water. DM water is often called "Hungry Water" as it rarely contains mineral and DM water is a very good solvent and will corrode the CS. The corrosion rate is not important. However, by this process DM water quality will degrade. Also, if any O2 or CO2 absorption has taken place in DM water, it will become quite corrosive. Normal carbon steel easily looses it's elements in DM Water because of poor corrosion stability and hence SS used. Even in SS you have to maintain a minimum flow rate and if there is any stagnancy SS can also get pitted and punctured due to local concentration cell regads