Which of the following pumps is not typically used for fire service applications?

Submersible pumps are generally not used in standard fire service applications due to their design and operational focus. These pumps are primarily intended for moving water from below the surface to above ground level, often used in scenarios like dewatering or draining flooded areas. In fire service, the need is more aligned with pumps that can deliver high volumes of water at pressure to extinguish fires effectively.

In contrast, centrifugal pumps, which are widely used in fire service, excel at moving large quantities of water through pipes and are efficient for achieving the pressure needed for firefighting operations. Piston pumps are also utilized when high pressure and precise flow control are needed, especially in specialized firefighting situations. Similarly, diaphragm pumps can handle differing fluid viscosities and can be effective in certain applications, though less common than the other types mentioned.

Thus, the characteristics and typical usage scenarios clearly distinguish submersible pumps from other options used in fire service, making them the least relevant choice in this context.