Compatibility note: wetted material selection for acid service

316 stainless is the catalog default and is appropriate for the great majority of aqueous, caustic and mild process duty. It is not appropriate for concentrated sulphuric acid above ambient temperature, for hydrochloric acid at any concentration, or for wet chlorine. In hot concentrated sulphuric service 316 corrodes at rates measured in millimetres per year, which on a pump casing means through-wall failure inside a single production campaign.

The MX-200 is the only catalog item with Hastelloy C-276 wetted parts. It is rated to 120 °C and carries ATEX II 2G Zone 1 certification, with a 70-day factory lead time. Above 120 °C in concentrated acid service there is no catalog selection: the enquiry is a special and must go to application engineering. Offering a 316 stainless pump against a stated Hastelloy requirement is not a commercial decision that can be made in the field.