PRIMUS Heat Exchangers Overview

Due to space constraints, PRIMUS has historically plumbed its heat exchangers in a reverse manner. In other words, the steam being condensed is contained within the tubes with the cooling water flowing over the tubes. This plumbing arrangement is fully approved by the OEM manufacturer.

The PRIMUS heat exchangers are all two-pass types.

The current PRIMUS heat exchanger supplier is Thermal Transfer Products of Racine, Wisconsin. The Company is ISO 9001:2008 registered.

Operating and Maintenance Notes

It is recommended that water strainers be installed ahead of this cooler when the source of cooling water is from other than a municipal water supply. Dirt and debris can plug the water passages very quickly, rendering the cooler ineffective.

Each heat exchanger has been cleaned at the OEM factory and should not require further treatment. If purchasing a replacement heat exchanger, it may prove useful to inspect the unit to be sure that no dirt or foreign matter has entered the unit during shipment.

When storing the unit, be sure to keep the oil and water ports sealed. If storage continues into cold winter months, the water chamber must be drained to prevent damage by freezing.

Any loss in heat exchanger efficiency can normally be traced to an accumulation of oil, sludge, or water scale.

Replace gaskets when removing end castings. It is recommended that gaskets be soaked in oil to prevent corrosion and ensure a tight seal.

Zinc anodes should be inspected two weeks after initial start-up. At this time, by visual inspection of the anode, determination of future inspection intervals can be made based on the actual corrosion rate of the zinc metal.

The zinc anodes must be replaced when 70% of the zinc volume has been consumed. These replacement anodes can be purchased from PRIMUS.

It may be necessary to clean the inside of the cooling tubes to remove any contamination and/or scale buildup. It is recommended that a fifty-fifty percent solution of inhibited muriatic acid and water be used. For severe problems, the use of a brush through the tubes may be of some help. Be sure to use a soft bristled brush to prevent scouring the tube surface causing accelerated corrosion. Upon completion of cleaning, be certain that all chemicals are removed from the shell side and the tube side before the heat exchanger is placed into service.

Pressure and Temperature Ratings

Maximum Shell Pressure 250 PSI
Maximum Tube Side Pressure 150 PSI
Maximum Temperature 350° F


Tubes Copper
Hubs & Tube Sheets Steel or Brass
Shell Steel or Brass
Baffles Brass
End Bonnets Cast Iron
Mounting Brackets Steel
Gaskets Nitrile Rubber/Cellulose Fiber
Nameplate Aluminum Foil

PRIMUS Improvement

In mid-September 2012, PRIMUS began adding an additional sacrificial anode immediately ahead of the water inlet of the jacket side of all heat exchangers. The former arrangement allowed for the protection of the steam or tube side, but not the water jacket side. The new anode fits into a tee that replaces the 90 fitting ahead of the inlet.

About ThermaSys (Parent Company of Thermal Transfer Products)

Founded in 1971 in Montgomery, Alabama as Thermal Components, Inc., ThermaSys is a leading manufacturer of low-volume, short-run, highly-engineered copper/brass, and aluminum heat exchanger components and assemblies. The Company’s low/ medium volume products consist of radiators, condensers, charge air coolers, oil coolers, shell/tube heat exchangers, and modules. Its higher unit volume products include seam-welded aluminum and brass tubing. Solutions are customized for clients in a diverse set of end markets, including electric power generation, industrial and construction equipment, oil and gas, automotive and truck, HVACR, and marine. ThermaSys operates from facilities in Alabama, Wisconsin, Germany, the United Kingdom, and China.

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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