The secret is the unique, floating Granco rotor. Pivoted in a spherical housing, the rotor provides positive expulsion of fluid from the pump chamber directly into the line of flow. The simplicity of the Granco design provides excellent fluid displacement without the use of gears, blades, vanes, paddles, scoops, pistons, valves or stators makes it the perfect design for stationary or truck-mounted applications.
A standard Granco rotary ball pump can move a tremendous variety of fluids with viscosities ranging from 30 to 1,000,000 SSU without modification of standard clearances. Product ranges include: PETROLEUM - from solvents through crude and lube oils. INDUSTRIAL - from water-based paints through caulking compounds. EDIBLE - from vegetable oils through molasses and peanut butter.
The Granco rotor has four large pumping chambers. These individual chambers are positioned so that incoming fluids flow directly to the heart of the rotor. Since fluids enter and exit the rotor cavities with less friction and less shear, the Granco pump displaces more product with greater efficiency than other designs. Gallon for gallon, Granco pumps will normally deliver more product at the same product at the same speed and require less horsepower than other positive displacement pumps.
The performance of a positive displacement pump depends upon maintaining the tolerances of the pumping mechanism. Operating speed attacks these tolerances. The floating Granco rotor minimize metal to metal contact in the pump. The large rotor cavities allow the Granco pump to operate at lower rpms. These features combine to preserve the pump's original tolerances. Thus, the Granco pump will run slower and longer and require less ongoing maintenance.