Tag: Hastelloy for sulfuric acid

Titanium or Hastelloy Bolts for Sulfuric Acid?

Q: I read that titanium regenerates a protective layer quickly in presence of water. Does that mean its okay to use it with sulfuric acid with steam present?

A: Titanium fasteners are probably not the best solution for sulfuric acid but may work depending on your concentration and temperature.  Titanium is best used for corrosion resistance to chlorides and salt water. For sulfuric acid, Hastelloy C276 bolts would be a much more robust solution and will be your best option for corrosion resistance to sulfuric acid for most conditions. However to be certain we would need to know the temperature and concentration of your application.

Alloy 20 Bolts for Sulfuric Acid (H2SO4)

Q:
I’m running a cotton mercerizing process that is being altered to utilize sulfuric acid. I didn’t realize how corrosive using sulfuric acid (H2So4) is on my fasteners. Any ideas on how to protect my bolts. Not super hot, just corrosive.
A:
Alloy 20 bolts are a good choice for this. It was specifically designed for use in hot sulfuric acid, easily handling boiling sulfuric acid in 20% to 40% concentration, as well as general sulfuric acid resistance. If Alloy 20 bolts do not do the trick then you can up your resistance to Hastelloy C276 bolts which are ideal for use in hot sulfuric acid at higher temperatures and concentrations than Alloy 20 fasteners.