What is the desired pump pressure when supplying a 2 1/2 inch hose line with a 50 psi nozzle pressure, laid up to the third floor and with a supply line of 250 ft?

Study for the Florida State Driver/Operator Test. Experience immersive flashcards and comprehensive multiple choice questions. Each query is supplemented with hints and thorough explanations. Prepare confidently for your exam!

To determine the desired pump pressure when supplying a 2 1/2 inch hose line, it's essential to consider several factors: the nozzle pressure, the elevation gain to the third floor, and the friction loss over the distance of the hose.

The nozzle pressure given is 50 psi, which is the pressure required for the nozzle to operate effectively. Additionally, when laying hose lines to a vertical height, there will be a loss of pressure due to the elevation. For every story that a hose line is laid up vertically, you typically add an extra 5 psi to account for elevation change. A typical residential third floor can be estimated to be around 30 feet or more. Thus, the elevation component would add approximately 15 psi (5 psi for each of the three floors).

Now, considering the friction loss due to the length of the hose, we use a general guideline for friction loss in a 2 1/2 inch hose, which is about 2 psi per 100 feet of hose. Since the supply line is 250 feet, the friction loss can be calculated as follows:

  • For the first 100 feet, the loss is 2 psi.

  • For the second 100 feet, it again adds another

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy