Name one type of boiler that a second class license holder is allowed to operate.

A second class license holder is specifically permitted to operate various types of boilers within their scope of training and qualifications. Among these, the fire-tube boiler is particularly common and falls within the operational capacity of a second class licensed individual.

Fire-tube boilers operate by having hot gases pass through tubes that are submerged in water contained in a larger vessel. The design allows for efficient heat transfer, as the hot gases heat the water, converting it to steam which can then be used for various applications. A second class boiler operator is trained to manage this system, which includes understanding operational parameters, safety protocols, and maintenance practices necessary to ensure safe and efficient operation.

While other types of boilers such as water-tube, electric, and condensing boilers exist, the specific training and operational limits outlined for a second class license focus heavily on the fire-tube boiler along with certain water-tube designs if specified. This operational focus ensures that licensed individuals are well-versed in the characteristics, safety requirements, and operational procedures essential for effective management of fire-tube boilers.