When used for underground thermal flooding in oil fields, what is the aggregate capacity limit for coil type drumless boilers under a Fourth Class Power Engineer's certificate?

The aggregate capacity limit for coil type drumless boilers used in applications such as underground thermal flooding in oil fields under a Fourth Class Power Engineer's certificate is indeed 10,000 lbs/hour. This regulation aligns with industry standards related to the safe and efficient operation of boilers, particularly in specialized circumstances like thermal flooding, where managing temperatures and pressures is critical to enhancing oil recovery.

Coil type drumless boilers are generally recognized for their design and operational characteristics, which allow them to achieve high thermal efficiency and quick response to load changes. However, due to these factors and the operational environment, regulatory bodies have established the 10,000 lbs/hour limit as a safety measure to ensure that operators can manage the inherent risks associated with higher capacities effectively.

The limits provided by the other options such as 20,000, 30,000, and 40,000 lbs/hour exceed the recognized safe operational capacity for Fourth Class Power Engineers in this specific context, thereby underscoring the importance of adhering to established guidelines for equipment use in oil fields.