In PRIMUS’ ongoing effort to introduce innovative “Green Technologies” to the field, the PRI-Saver™ Total Recirculation Vacuum Pump System (TRVPS) was created for medium and large PRIMUS steam sterilizers.

The system is designed to save 90% of the water required in operating the vacuum pump system. Depending on sterilizer usage, water usage savings can amount to thousands of gallons per month.

The complete package includes a SIHI liquid ring vacuum pump, motor, separator, heat exchanger, and accessories. All the components are mounted on a frame skid for ease of installation.

The PRI-Saver TRVPS can now be ordered on all units with vacuum pumps that range in size from 2 – 15 HP. The system can also be retrofitted in the field on existing steam sterilizers.

Recirculated chilled water

A facility must have a recirculated chilled water system for the TRVPS to function. However, good news…
the sterilizer heat exchanger will be plumbed for chilled water when you order a new steam sterilizer with the TRVPS package.

Theory of Operation

The service liquid that enters the vacuum pump is discharged into the recirculation tank. Then, the service liquid from the tank is cooled using a heat exchanger that is separate from the sterilizer heat exchanger.

Lastly, the cooled service liquid is returned to the vacuum pump.

  • Approximately 90% of the total service liquid flow is comprised of the recirculated liquid
  • Approximately 10% of freshwater supply is added to the flow as make-up water
  • The recirculation tank provides for the discharge of overflow to the drain
  • The recirculation tank also provides for manual draining of the system

System Components

  • A SIHI liquid ring vacuum pump (2 – 15 HP) close-coupled to an energy-efficient, 3/60/ 460 volt motor
  • Suction line check valve, vacuum relief valve, and liquid-filled vacuum gauge with an isolation valve
  • Discharge separator tank with tubular gauge glass, vent, and overflow connections
  • Service liquid shell and tube heat exchanger
  • Piping and fittings for the above components
  • Fabricated structural steel skid for the above components

Materials of Construction

Vacuum Pump

Casing: Cast Iron
Impeller: Bronze
Shaft: Steel
Bearings: Grease lubricated, integral to the motor
Shaft Sealing: Single mechanical seals, Buna elastomers, carbon vs. ceramic faces


Stainless steel

Heat Exchanger

Shell: Carbon steel
Tubes: Copper




Stainless and brass




Alkyd enamel

Skid Frame

Carbon steel

Connections to the skid

  • Two (2) connections for the chilled water to and from the heat exchanger
  • One (1) connection to the vacuum pump inlet
  • One (1) tank manual drain to the sterilizer drain
  • One (1) tank overflow to the sterilizer drain
  • One (1) or two (2) vacuum pump cavitation port(s) to drain – depending on the pump size

How to Order

PRI-Saver™ Water Conservation Systems can be ordered through our online parts store, contacting our parts store at 877.679.7800 extension 1010 or email at

Have a question or having difficulties? Talk to Dave Schall, our PRIMUS sterilizer expert who is here to assist you anytime at 877.679.7800 extension 1212 or email at

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