According to your experience, what material should be used for piping with anhydrous HCl? Process conditions are: Temp: -35 to 50 °C ( -31 to 122 F) Press: FullVacuum to 45 bar. Thank you! Phil

>If it is really and perfectly anhydrous it is Non-Corrosive >and MOC selection may not be a critical issue. But in >practical cases due to moisture ingress or otherwise some >aquous can interfere and in that case it will be >significantly corrosive and you have to select suitable >materials which often are a costlier one. For example you >have to select Hastealloy B-2 or Alloy C- 276 of suitable >design. > >regards and if you do have any further alternate inputs pl. >revert. > >DM Thank you for your reply. I'm aware of the suitability of materials like Hastelloy but I'm also aware of their cost! As you correctly state, I think that it would be somehow impractical to assume that moisture will never enter the system, so corrosion risk can't be totally eliminated. According to several sources ordinary carbon steel would perform well, showing even more resistance to wet corrosion (HCl + water) than stainless steel. The problem might be low operating temperatures. Any experience on this problem? Would you consider using low-temp carbon steel? Phil