Lesson 3: Dynamic Pressure
Relationship of Pressure and Flow Math Examples

P2 = Pressure on Day 1
P1 = Pressure on Day 2

Q2 = Flow on Day 1
Q1 = Flow on Day 2

Pressure and Flow Relationship in a Fixed System

To solve for unknown flow:

Problem 1

On a water system one day you measure a flow of 1000 GPM and pressure of 50 PSI. The next day you measure a pressure, it is 30 PSI. What is the flow?

Problem 2

On a water system one day you measurea flow of 700 GPM and pressure of 60 PSI. The next day you measure a pressure, it is 100 PSI. What is the flow?

Problem 3

On a water system one day you measure a flow of 370 GPM and pressure of 43 PSI. The next day you measure a pressure, it is 61 PSI. What is the flow?

Problem 4

On a water system one day you measure a flow of 790 GPM and pressure of 37 PSI. The next day you measure a pressure, it is 44 PSI. What is the flow?

Problem 5

On a water system one day you measure a flow of 660 GPM and pressure of 83 PSI. The next day you measure a pressure, it is 91 PSI. What is the flow?

To solve for unknown pressure:

Problem 6

On a water system one day you measurea flow of 740 GPM and pressure of 72 PSI. The next day you measure flow, it is 610 GPM. What is the pressure?

Problem 7

On a water system one day you measure a flow of 280 GPM and pressure of 46 PSI. The next day you measure flow, it is 570 GPM. What is the pressure?

Problem 8

On a water system one day you measure a flow of 325 GPM and pressure of 49 PSI. The next day you measure flow, it is 510 GPM. What is the pressure?

Problem 9

On a water system one day you measure a flow of 660 GPM and pressure of 88 PSI. The next day you measure flow, it is 750 GPM. What is the pressure?

Problem 10

On a water system one day you measure a flow of 785 GPM and pressure of 68 PSI. The next day you measure flow, it is 920 GPM. What is the pressure?

Problem 11

On a water system one day you measure a flow of 180 GPM and pressure of 31 PSI. The next day you measure flow, it is 340 GPM. What is the pressure?