Question 257General Subjects - 1st Asst/Chief

The correct answer is A) Pour point and viscosity. The pour point and viscosity of the fuel oil are the most important properties to determine the appropriate temperatures to maintain throughout the fuel forwarding and service systems. The pour point is the lowest temperature at which the fuel will still flow, while viscosity measures the resistance of the fuel to flow. Maintaining the proper temperature range based on these properties ensures the fuel can be efficiently pumped and atomized for combustion, preventing issues like fuel starvation or incomplete burning. The other options are not as directly relevant to determining operating temperatures. Density and compatibility are more important for ensuring the fuel is suitable for the engine, while water content and ignition quality/caloric value are not the primary factors in setting fuel system temperatures.