Massachusetts 2nd Class Fireman's Practice Exam

Which type of boiler features diagonal stays?

1. Fire-tube boilers

2. Water-tube boilers

3. Cast-iron boilers

4. Waste heat boilers

The correct answer is: Fire-tube boilers

Diagonal stays are a key structural feature found primarily in fire-tube boilers. These stays provide additional support to the boiler shell and help to manage the stresses that occur as a result of the internal pressure and the thermal expansion that takes place during operation. In fire-tube boilers, hot gases produced by combustion flow through tubes surrounded by water, and the design must accommodate the heating and dampening effects of these gases. The diagonal stays serve to maintain the integrity and shape of the boiler under varied conditions, enhancing both safety and efficiency. Other types of boilers, like water-tube, cast-iron, or waste heat boilers, have different structural requirements and designs, such as the arrangement of tubes or the materials used, which do not typically incorporate diagonal stays in the same manner as fire-tube boilers. Therefore, understanding the role of diagonal stays specifically in the context of fire-tube boilers highlights their significance in ensuring the boiler's operational reliability.