Model Test Laboratory

Axial and Mixed Flow Pumps which exceed the power or capacity capabilities of the regular testing laboratory receive the same through study in the industry’s most modern test laboratory. Here, under ideal research conditions, is a complete closed-loop system. Pump capacity is measured by a calibrated venturi meter and pump discharge is measured by a manometer, graduated to one-tenth of one inch. Power is supplied by a variable speed DC drive motor. Power measurement is by digital readout meters as is the rotational speed supplied by a tachometer generator. Water temperature is measured in °C by a bimetallic dial indicator thermometer. Model performance conditions are determined by prototype performance conditions and the model scale ratio. When the model pump meets the equivalent prototype conditions, the model ratio is used to scale-up all dimensions of the model pump to determine the dimensions of the prototype pump.

Cavitation Testing

Model Axial and Mixed Flow Pumps can be tested for cavitation characteristics, with the model scale ratio used to predict performance of prototype pumps. The model test laboratory is equipped with a vacuum pump which is capable of creating a vacuum of one inch of mercury absolute. Varying vacuum in the closed-loop model test system while maintaining constant capacity and speed varies the available NPSH to determine the cavitation parameter, sigma. From cavitation test data, curves of sigma versus efficiency are generated at selected capacities and speeds. Atmospheric pressure is measured by a Fortin type standard mercurial barometer. Careful attention to testing details is only one of many steps taken by Patterson Pump Company to ensure that every pump lives up to our credo of “Progress Through Performance.”