Cardinal Pumps”offers a line of pumps designed to meet the requirements oftransformer-oil applications. To meet the extreme temperatures commonto such environments, the pumps are rated for continuous-duty operatingtemperature ranges from –40 C (–40 F) to 100 C (212 F). The  pumpsalso have other special features for transformer-oil applications, suchas the capability to permit thermo-siphon flow when the pump is notoperating, allowing natural convection even when the pump is completelyshut off. For long life inthe field, all pumps offer rugged split-casing design withheavy-duty class 30 cast iron for the pump casting, motor enclosures,impellers, and volutes. Large thrust face sleeve bearings also extendlife, minimize wear, and reduce maintenance. Cardinal offers threebearing types: standard sleeve bearing, the Harley sleeve bearing, andthe Harley sleeve bearing with TecSonics bearing wear monitoring. AllCardinal pump and motor units are subjected to pressure tests to 50PSIG to ensure the integrity of the complete unit. Motor windings areall tested for 60 seconds at 2x voltage + 1000 to ensure electricalintegrity and continuity, with winding resistance taken both before andafter the pump is built. Pumps are also meggar tested to ensure theintegrity of the insulation.