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Pumps specifically designed for transformer oil applications

Pumps specifically designed for transformer oil applications
Unifin, a supplier of cooling equipment and transformer oil pumps and valves to the power generation and power transformer industries, offers its line of transformer oil pumps, manufactured under the company’s Cardinal brand. Cardinal pumps are the industry’s only pumps that are specifically designed to meet the demanding requirements of transformer oil applications.

To meet the extreme temperature requirements, Cardinal pumps are rated for continuous duty operating temperature ranges from –40ºC (–40ºF) to 100ºC (212ºF). The pumps also have other special features for transformer oil applications, such as the capability to permit thermo-siphon flow when the pump is not operating, allowing natural convection even when the pump is completely shut off.

For long life in the field, all Cardinal pumps offer rugged split casing design with heavy-duty class 30 cast iron used for the pump casting, motor enclosures, impellers and volutes. Large thrust face sleeve bearings also extend life, minimize wear, and reduce maintenance. Cardinal offers three bearing types: standard sleeve bearing, the Harley sleeve bearing by Cardinal, and the Harley sleeve bearing with TecSonics bearing wear monitoring. As a result of their design, Cardinal pumps are low maintenance and long-lasting. With no mechanical seals, repair and upkeep is reduced in utilizing two gasket seals on each pump. Cardinal pumps are durable and resilient as a result of a design that allows transformer oil flow back through the motor and bearings, thereby providing cooling and lubrication.

All Cardinal pump and motor units are subjected to extensive testing, including pressure tests to 50 psig to ensure the integrity of the complete unit. Motor windings are all tested for 60 seconds at (2 x voltage + 1000) to ensure electrical integrity and continuity, with winding resistance taken both before and after the pump is built. All Cardinal pumps are also meggar tested to ensure the integrity of the insulation.