What is the pump discharge pressure when connected to a dry standpipe with two 3-inch lines, each 100 feet in length, and using a 2-inch lightweight hose with a 1-inch tip?

To determine the pump discharge pressure when connected to a dry standpipe with the given specifications, we need to consider several factors including the elevation loss, friction loss in the hoses, and the nozzle pressure.

1. Friction Loss in the Hose: The friction loss in a 2-inch lightweight hose is a critical component. For a standard calculation, the friction loss can be estimated using the formula:

Friction Loss (in psi) = (Length of hose in feet / 100) × (flow rate in GPM^2 / diameter in inches^2)

While the specific flow rate is not provided in this question, we can use an approximate value for a typical 2-inch nozzle and the length of hose to determine the overall pressure needed.

2. Elevation Loss: If the standpipe is not at ground level, we must consider any elevation gains that would increase the required discharge pressure. However, the question does not specify any elevation gain, so we can assume that the standpipe is at the same level as the pump.

3. Nozzle Pressure: The required nozzle pressure for a particular flow rate through a 1-inch tip is also essential. Generally, an engine delivering to a nozzle