How much friction loss should be accounted for when pumping to a standpipe connection on the 10th floor?

The correct answer indicates that 45 psi should be accounted for when pumping to a standpipe connection on the 10th floor. This figure is based on several factors regarding the hydraulic calculations required in firefighting scenarios.

When water is pumped to a standpipe, the friction loss due to the elevation gained and the flow through the pipes must be considered. Each floor typically represents a certain pressure loss due to the height the water has to be pumped against gravity, often estimated at around five psi per floor. Therefore, for a building with ten floors, a substantial pressure loss occurs purely from elevation (approximately 50 psi for 10 floors, though this may be adjusted based on actual conditions and the specific building layout).

The reported friction loss also takes into account the resistances within the piping system, such as bends, fittings, and the length of the hose or pipe. In this case, the choice of 45 psi likely represents an accepted standard in practice for overcoming both the vertical lift and the additional frictional losses in the system for that height.

Using this knowledge helps firefighters accurately estimate the pressure needed to effectively deliver water to the upper floors, ensuring that adequate pressure reaches the standpipe connections for effective firefighting operations.