KanBeng model records list material options as tags: cast iron, 304, 316L, PTFE, duplex. Those tags are a filter. They are not a corrosion analysis. A factory that can pour all five will still default to the cheapest unless the RFQ names parts.
Ask for a schedule, not a slogan
Require casing, impeller, wear rings, shaft, shaft sleeve, seal faces and elastomers as separate lines. “SS pump” often means a stainless impeller in a cast-iron body, or 304 where the drawing said 316L. For lined pumps, name the lining thickness, spark-test requirement and what happens at the impeller eye.
Chlorides punish 304
304 is a common catalog upgrade that still pits in warm chloride service. 316L is better, not immortal. Duplex grades and high-alloy irons exist because 316L has limits. If you do not know the chloride level, say you do not know; do not pick 304 because it is on the model page.
Acids, alkalis and solvents are not one family
Fluoroplastic-lined and magnetic-drive constructions exist for a reason. They introduce other failure modes: permeation, liner collapse, dry-run of a containment shell, torque limits. A metallic chemical pump and a lined pump are different machines even when the series letters look similar on a quote.
Seals fail first
Face materials and elastomers often die before the casing. Name the seal plan, faces and O-rings. If the factory answers with “mechanical seal, good quality”, they have not bid the seal.
Use the index, then leave it
Filter KanBeng records by material tag to drop obviously wrong families. Then put chemistry, temperature and the part-by-part schedule in the RFQ. If you need a corrosion allowance or a lined construction, say that in words; the tag list cannot infer it.