Question 55Safety & Environmental - 1st Asst/Chief

You are correct, the answer A) Friction in the piping and valves is the common cause for the lower water pressure at the fire hose outlet compared to the discharge of the pump. The reason for this is that as the water flows through the piping and valves, it encounters resistance due to friction. This friction causes a pressure drop, resulting in a lower pressure at the fire hose outlet compared to the pump discharge. The amount of pressure loss depends on factors like the length and diameter of the piping, the number and type of valves, and the flow rate of the water. The other options, B) Wear in the hydrant, C) Leaky pilot valve, and D) Leaky pump suction valve, are not the common causes for this pressure drop, as they would not affect the pressure along the entire length of the piping system in the same way that friction does.