MEDIA GUIDE
Sodium Hydroxide (Caustic) Pumps
Well-behaved when cold and dilute — stress-corrosion cracking is the trap at the hot, strong end.
The properties that drive the choice
| Hazard profile | none of note |
|---|---|
| Concentration band in our data | 0–50% |
| In one line | Stainless steels good to ~80°C (316L preferred over 304 — sensitization in welds is the weak link); above that caustic stress-corrosion cracking risk rises sharply — nickel alloys (Monel) or PTFE at high temperature. |
Which pump families serve it
At a reference duty (20 °C, 10 m³/h, 30 m). Your duty point may move the answer — run it through the tool below; the full report adds the alternatives worth quoting in parallel.
| Primary answer | End-Suction Centrifugal Pump (ANSI B73.1) | Clean or lightly contaminated fluids, moderate duty, flows ~2–400 m³/h |
|---|---|---|
| Typical wetted materials | Polypropylene (PP), Cast Iron, Carbon Steel, Stainless Steel 304, Stainless Steel 316L, PTFE / FEP lined, Monel 400, Hastelloy C-276 | |
Where the boundaries sit
- Caustic stress-corrosion cracking is temperature- and concentration-driven; the combination decides the material
- Caustic crystallises on standing — the pump that restarts against crystals is a failure mode, plan the flush
- Elastomer choice matters as much as metal choice; caustic swells the wrong rubber
Related reading
Pumping this fluid? The selector on the home page maps your concentration, temperature and duty point to a pump type and wetted materials for this exact medium — free.
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