Given a hose with a flow rate of 50 gpm and a friction loss of 2 psi, if the flow rate increases to 200 gpm, what will the friction loss increase to?

• A. 8 psi
• B. 16 psi
• C. 24 psi
• D. 32 psi

Answer: (D)

When considering how friction loss in a hose increases with flow rate, it is important to understand that friction loss is not a linear relationship. Instead, it is commonly represented in the formula for friction loss, which can be simplified for calculation as:

Friction Loss (in psi) = (Flow Rate in gpm)^2 × C

where C is a constant that depends on the specific hose diameter and material. This means that if you increase the flow rate, the friction loss increases with the square of the flow rate.

In this scenario, you start with a hose flowing at 50 gpm with a friction loss of 2 psi. If you increase the flow rate to 200 gpm, the change in flow rate is four times the initial rate (200 gpm is four times 50 gpm). Given the square relationship, the friction loss will increase by a factor of 4 squared, which is 16.

To summarize, the increase in friction loss from 2 psi at 50 gpm can be calculated as follows:

At 50 gpm, you have a friction loss of 2 psi.

At 200 gpm, you would expect the friction loss to be:

Friction Loss at 200 gpm =