One chemical compatibility table I have suggests 316 Stainless, Hastelloy C-276, PTFE, and tantalum. From years of experience in designing custom instrumentation for the chemical and plastic industries, I believe that 316 SST must be a misprint. Stainless steel has very little resistance to halogens*. I hope you have deep pockets if you use Hastelloy C-276 (or possibly Hastelloy B). I once _had_ some expert machinist friends until I had them make some C-276 parts for me! As a general rule, tantalum is similar to glass in its compatibility properties. Often when glass-lined reactors had a pinhole in the glass, they would be drilled out and a tantalum bolt with beveled washer would be used to seal the hole.
My quick, off-the-wall guess would be a PTFE, Kel-F, Kynar or other fluoropolymer lined pump body and impeller. Also worth more investigation would be ordinary chlorinated PVC as it is recommended by Corzan Industrial Piping for cadmium chloride solutions at 200 F. Ceramic pumps are also a possibility.
Dr. Barry L.Ornitz
Automobile stainless exhaust systems are corroded quickly in winter when the streets are salted!