From the graph shown in the illustration, determine the size of the regulating ring required for the proper operation of the fuel oil centrifuge if the fuel oil specific gravity is 0.9 kg/dm3 at 68°F, and the separating temperature is 158°F. Illustration MO-0113

Correct Answer: Option D — 110 mm

Centrifuge gravity disc sizing depends on oil density and separating temperature. Entering the manufacturer's temperature and specific gravity nomograph (MO-0113) at the specified values dictates a 110 mm regulating ring to maintain the dynamic interface position correctly.