Seawater Desalination Feed Pumping

Overview

Seawater desalination in India is expanding beyond large municipal projects into industrial self-supply — coastal chemical plants, power stations, and petrochemical facilities in Gujarat (Jamnagar, Hazira), Maharashtra (Ratnagiri, Raigad), Tamil Nadu (Chennai, Tuticorin), and Kerala (Kochi) are installing seawater RO systems to reduce dependence on freshwater allocation and municipal supply. Seawater RO requires sustained high-pressure feed — 55–80 bar — that only positive-displacement pumps can maintain reliably over continuous operation.

SEW's Vanguard Series triplex plunger pump is built for high-pressure seawater feed service: duplex stainless steel wetted parts, 55–80 bar operating range, and continuous-duty construction suitable for 24×7 coastal industrial RO operations.

How It Works

Pre-treated seawater (after coagulation, filtration, and cartridge filtration to 5 micron) enters the triplex pump at 3–5 bar boost pressure from the low-pressure feed pump. The triplex high-pressure pump raises feed pressure to 55–80 bar and delivers it to the RO membrane pressure vessel array. VFD control maintains set operating pressure regardless of membrane fouling-induced resistance increase during inter-cleaning cycles.

Bare Unit Use

Desalination system integrators and coastal industrial EPC contractors order the bare high-pressure seawater pump for new RO installations or to replace worn pump units in operating desalination plants. Duplex stainless steel (DSS 2205) wetted parts standard for seawater chloride resistance. Flow: 40–200 LPM, pressure: 55–80 bar. Energy recovery device (ERD) bypass connection available.

Skid Package Use

SEW supplies complete high-pressure feed pump skids for seawater RO: duplex SS triplex pump, motor, VFD, pressure transmitter, high-pressure gauge, relief valve, and ERD bypass manifold — all on a common SS skid frame. Used in: coastal industrial water self-supply (Gujarat, Maharashtra, Tamil Nadu, Kerala), island water supply systems, and coastal resort and hospitality water treatment.

Why SEW

Duplex SS 2205 wetted parts standard — chloride and pitting corrosion resistance for continuous seawater service. No SS 316 wetted parts that pit in high-chloride seawater within 18–24 months.

55–80 bar continuous duty — rated for continuous 24×7 seawater RO operation. Not a pressure-tested-to-rating pump — a continuous-duty rated pump.

VFD pressure feedback control — maintains set feed pressure as membrane fouling resistance increases between CIP cycles, without operator intervention.

Indian manufacturer, Nashik — coastal industrial clusters in Gujarat and Maharashtra are within 6-hour delivery radius. Fast spare parts for coastal plants where saltwater pump failure means production stoppage.