Which factor does NOT influence the pump chart calculations?

Water temperature does not influence pump chart calculations because pump charts are primarily based on mechanical and hydraulic principles rather than thermal properties of water. The essential factors that affect the pump's performance, such as flow in gallons per minute (GPM), hose length, and hose diameter, directly impact how the pump works under specific conditions.

Flow in GPM determines how much water is being moved and can directly affect the pressure the pump needs to produce. Hose length plays a critical role because longer hoses contribute to friction loss, requiring the pump to work harder to maintain the desired flow rate. Hose diameter influences the volume of water that can travel through the hose and affects friction loss as well. These aspects are vital for accurate calculations in determining the pump's performance in various firefighting scenarios. In contrast, while water temperature may affect other aspects of firefighting, such as water viscosity, it does not substantially alter the fundamental calculations found in pump charts.