I'm specing a pump for Flare Drum in HF Alky unit. API shows S-9 material but I assume that's for concentrated acid. Looking for actual service experience.
Without knowing details I can't tell you 100%, but Alloy C276 is used in canned pumps for this duty. Hope that helps.
Companies that I know of that have done this successfully are HMD Kontro (Sundyne) and Hermetic. Of the two, I prefer Hermetic, but HMD are very fine pumps too.