Water Treatment: The Largest ANSI Pump Market
Water and wastewater treatment represents one of the largest application segments for ANSI B73.1 process pumps. From raw water intake to finished water distribution, from chemical dosing to sludge handling, ANSI process pumps move water and treatment chemicals through municipal and industrial facilities across North America.
While water may seem benign, water treatment presents unique engineering challenges: corrosion from treatment chemicals, abrasion from suspended solids, scaling from hardness minerals, and the relentless demand for reliability in critical public health infrastructure.
Key Applications and Material Requirements
Chemical Dosing — Coagulants and Flocculants
| Chemical | Challenges | Recommended Material |
|---|---|---|
| Aluminum sulfate (alum) | Acidic (pH 2.5-3.5) | Alloy 20 or 316SS (dilute only) |
| Ferric chloride | Highly corrosive, chlorides | Titanium or Hastelloy C |
| Polymer solutions | Viscous, shear-sensitive | 316SS |
Lime Slurry / Softening
- Material: CD4MCuN or 316SS with hardened wear rings
- Special considerations: Open impeller preferred; flush plans for mechanical seals to prevent solids accumulation
Membrane Feed — RO and Nanofiltration
- Brackish water: CD4MCuN duplex stainless (resists Cl-SCC that attacks 316SS)
- Seawater RO: Super duplex (2507) or Titanium
- High pressure: Class 300 or 600 lb casing rating
Finished Water Distribution
- 316SS wetted components for corrosion resistance
- NSF/ANSI 61 certified materials for potable water contact
Wastewater Sludge Handling
- CD4MCuN for corrosion + abrasion resistance
- Semi-open impeller for solids handling
- Avoid cast iron — H₂S in wastewater produces sulfuric acid via bacterial action
Material Selection Summary for Water Treatment
| Service | Recommended Material | Alternative | Avoid |
|---|---|---|---|
| Clean water, ambient | Ductile Iron (coated) | 316SS | — |
| Potable water (NSF 61) | 316SS or coated DI | — | Uncoated cast iron |
| Alum (liquid) | Alloy 20 | 316SS (dilute only) | Cast iron, carbon steel |
| Ferric chloride | Titanium | Hastelloy C | 316SS |
| Sodium hypochlorite | Titanium | PVC/CPVC (small pumps) | 316SS, Alloy 20 |
| Caustic soda (<30%, <150°F) | 316SS | Nickel | Cast iron |
| Caustic soda (>30% or >150°F) | Nickel (CZ100) | — | Stainless steels |
| Lime slurry | CD4MCuN | 316SS with hardened rings | Cast iron |
| Brackish water | CD4MCuN | Super Duplex (2507) | 316SS |
| Seawater | Titanium or Super Duplex | — | 316SS, CD4MCuN |
Supporting Water Treatment Infrastructure
We deliver 100% compatible replacement components with the material traceability and lead times your project demands. NSF/ANSI 61 certified materials available for potable water applications.