What grade of oil is used in the oil separator on a MC-7 air compressor if the temperature is above 40 degrees F?

In the context of using an oil separator on an MC-7 air compressor at temperatures above 40 degrees Fahrenheit, the choice of oil grade is essential for effective lubrication and performance. The correct answer specifies OE/HDO 30 oil. This grade is suitable for the typical operating conditions of the compressor at higher temperatures, providing a proper balance of viscosity and flow.

OE/HDO 30 oil is designed to maintain its viscosity and performance characteristics under the heat and operational demands that an air compressor can experience. At temperatures above 40 degrees F, this oil ensures that the compressor functions smoothly, reducing wear and potential overheating.

Selecting OE/HDO 10 or SAE 10W30 could lead to insufficient lubrication under high-demand scenarios, as these oils may not provide the necessary viscosity at elevated temperatures. Similarly, while SAE 10W40 offers a higher viscosity, it might be more suitable for different conditions or equipment specifications. Hence, OE/HDO 30 is the most appropriate choice to ensure optimal performance of the MC-7 air compressor under the specified temperature conditions.