Desalination Pumps (RO Feed, Pretreatment & Chemical Handling)
Hit recovery targets while protecting membranes and chemistry handling. We package high‑pressure multistage for RO feed, vertical turbine for intakes and bays, end‑suction for CIP/backwash, and mag‑drive sealless for corrosive chemical transfer. Dose control is handled by digital diaphragm metering. Brands: Grundfos, Goulds, Griswold, LMI, Walchem, Neptune, Emec, Finish Thompson, Iwaki, Flux and J.L. Wingert.
Best‑Fit Pumps for Desalination Duty
| Task | Best Pump Type | Recommended Brands | Why It’s Best |
|---|---|---|---|
| RO high‑pressure feed (BWRO 150–400 psi, SWRO 600–1,200 psi) | High‑pressure multistage (stainless/duplex) | Grundfos CRN/CRNE, Goulds multistage | Steep curves and efficiency at pressure; compatible with ERD‑based control |
| Seawater/Brackish intake & wet wells | Vertical turbine | Goulds | Bowls below liquid for NPSH margin; corrosion‑resistant metallurgy |
| Media filter backwash / cartridge flush | End‑suction centrifugal | Grundfos, Griswold | High flow for short intervals; easy isolation and service |
| RO CIP recirculation | End‑suction stainless centrifugal | Grundfos | Delivers required velocity for membrane cleaning loops |
| Antiscalant, bisulfite, acid/caustic dosing | Digital diaphragm metering | LMI PD/TD, Walchem EWN, Neptune 500/600, Emec, Grundfos DDA/DMX | High turndown, PVDF/PTFE heads, pulse/4–20 mA controls |
| Chemical transfer to day‑tanks | Mag‑drive sealless centrifugal (PP/PVDF/ETFE) | Finish Thompson DB/UC, Iwaki MX/MD | No seals → fewer leaks; excellent compatibility with oxidants/corrosives |
| Drum/IBC unloading | Drum/IBC pump | Flux F‑Series | Ergonomic, fast unloading; XP motor options; chemical tubes |
| Verification & accessories | Tanks, calibration columns, injection quills | J.L. Wingert | Stabilizes dosing; provides measurable calibration and safe injection |
Recommended Desalination Packages (Placeholders)
Tip Share design recovery & flux, feed TDS/temp, target permeate flow/pressure, and pretreatment scheme. We’ll return curves, metallurgy and a complete BOM.
How We Engineer RO & Pretreatment
- Hydraulics—size to required membrane pressure at design flux and recovery; verify NPSH and suction conditions.
- Metallurgy—duplex/super‑duplex for chloride service; 316/904L where appropriate; plastics for chemical loops.
- Controls—VFDs for feed control, interlocks with ERD/controller, pressure/flow monitoring and alarms.
- Chemistry—PVDF/PTFE wet ends for dosing; sealless transfer for oxidants and acids.
- Maintainability—back‑pull‑out designs, isolation spools, strainers, and clear layout for CIP.
Common Desalination Uses
- BWRO & SWRO feed skids
- Seawater/brackish intakes
- Pretreatment backwash
- RO CIP loops
- Antiscalant & bisulfite dosing
- Post‑treatment pH trim
- Demineralized/pure water makeup
- Industrial reuse & ZLD pre‑concentration
- Chemical transfer & day‑tanks
- Instrumentation calibration
Lower Energy, Longer Membrane Life
Send recovery, flux, feed TDS/temp, target permeate, and P&ID. We’ll quote a corrosion‑resistant, efficient package with curves and complete accessories.
Desalination FAQs
How much pressure do RO feed pumps need?
Brackish RO typically runs ~150–400 psi; seawater RO ~600–1,200 psi depending on temperature, salinity and recovery. We size to membrane curves plus control margin.
Why use duplex stainless for seawater?
Duplex grades improve chloride stress‑corrosion resistance and strength versus 316/304 in seawater service, extending pump life at pressure.
How do I prevent metering pump vapor‑lock on oxidants?
Use degassing heads, flooded suction, short suction lines and a back‑pressure valve with vertical discharge to keep checks seated.