Stainless steel is a material that does not react to deionized water. Stainless steel contains a low amount of carbon.
It also contains 10 percent per weight of chromium. It also contains nickle, molybdenum and nitrogen which, combined with the chromium, makes stainless steel very corrosion resistant.
For this reason, stainless steel is a material that is not corroded when it comes in contact with deionized water.
Nickel plating is an effective way to protect metal from corroding when it comes in contact with deionized water. This is because the nickel plating which contains 9 percent of a phosphorous-nickel alloy.
PVC is another material that is compatible with deionized water. PVC does not conduct electricity, and is resistant to chemicals.