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Marine & Offshore — Ejector Applications

Pump priming, bilge / ballast / cargo systems and fresh water generators

Bilge, Ballast & Cargo Pump Priming

Marine centrifugal pumps handling bilge water, ballast water and liquid cargo are installed below the waterline and must be primed before starting. Air ejectors (compressed air driven) are used as priming ejectors to evacuate the pump suction line and casing, allowing the pump to self-prime reliably before start. A pressure switch on the pump discharge automatically cuts out the ejector when full flow is established. Primetech manufactures a complete range of marine ejectors to class society standards (Lloyd's, DNV, Bureau Veritas) for newbuilding and retrofit.

Service
Bilge / Ballast / Cargo
Motive Fluid
Compressed air / Sea water
Standards
LR, DNV, BV, ABS
Class society approved design Stainless or bronze construction Auto-cutout on full flow Seawater-resistant materials

Fresh Water Generator Vacuum

Shipboard fresh water generators (FWGs) produce potable water by flash evaporation of sea water under vacuum (typically 60–90 Torr), using waste heat from the main engine jacket water. Steam ejectors — or more commonly, sea water jet ejectors using high-pressure sea water as motive fluid — maintain the vacuum in the FWG evaporator and condenser. Primetech sea water jet ejectors in seawater-resistant materials (naval brass, Duplex SS) are proven in FWG service across multiple vessel classes.

Sea water motive capability Naval brass or Duplex SS Handles flash vapour loads

Other Steam & Gas Ejector Applications