Unifin”sline of transformer oil pumps, manufactured under the company’sCardinal brand, are specifically designed to meet the requirements oftransformer-oil applications. To meet extreme temperature requirements,the Cardinal pumps are rated for continuous-duty operating temperatureranges from –40 C (–40 F) to 100 C (212 F). The Cardinal pumps alsohave other special features for transformer-oil applications, such asthe capability to permit thermo-siphon flow when the pump is notoperating, allowing natural convection even when the pump is completelyshut off. For long life in the field, all Cardinal pumps offer splitcasing design with heavy-duty class 30 cast iron used for the pumpcasting, motor enclosures, impellers, and volutes. Large thrust facesleeve bearings also extend life, minimize wear, and reducemaintenance. Cardinal offers three bearing types: standard sleevebearing, the Harleysleeve bearing by Cardinal, and the Harley™ sleeve bearing withTecSonics™ bearing wear monitoring. All Cardinal pump and motor unitsare subjected pressure tests to 50 PSIG to ensure the integrity of thecomplete unit.  Motor windings are all tested for 60 seconds at (2x voltage + 1000) to ensure electrical integrity and continuity, withwinding resistance taken both before and after the pump is built. AllCardinal pumps are also meggar tested to ensure the integrity of theinsulation.