Q: We’re using sodium hydroxide as a water treatment chemical to raise the pH of water but are experiencing corrosion. Is there a material that can handle this?

A: Typically for caustic soda (sodium hydroxide) corrosion, you might want to consider Nickel 200 bolts. Nickel 200 is best known for its resistance to caustic soda in all concentrations. The only drawback is that Nickel 200 isn’t particularly strong (60-85 KSI UTS) and can severely attacked by oxidizing salt solutions.

Q: I’m running a chlor alkali process to produce sodium hydroxide. We would like bolts that have a strong resistance to the NaOH. Should I try hastelloy?

A: In terms of caustic alkaline solutions, such as sodium hydroxide, your best bet would be Nickel 200 bolts which are known to have excellent resistance to all concentrations of caustic soda – even at high temperatures.