Question 310Motor Plants - Assistant Engineer

The correct answer is D) Soft copper. Soft copper is the recommended gasket material for high-pressure fuel oil lines on a diesel engine. Copper is durable and can withstand the high pressures and temperatures in these fuel systems without degrading over time. The soft, malleable nature of copper also allows it to create a tight seal around the fuel line connections. The other options are not suitable for this application. Fiberglass (A) and sheet asbestos (B) are not as durable or flexible as copper. Neoprene (C) is a rubber-based material that may not hold up well to the fuel oil and heat in the system.