Distribution exams love pressure questions because they look simple until the units start moving around. If you understand the relationship between psi and feet of head, most of these problems become routine.
The conversion to memorize
The key conversion is:
1 psi = 2.31 feet of head
That means:
psi = feet of head ÷ 2.31feet of head = psi × 2.31
If a tank water level is 115 feet above a service connection, the static pressure at that point is about 50 psi.
Static pressure vs working pressure
Static pressure is what you have when water is not moving. Working pressure is what remains while water is flowing through mains, valves, meters, and services.
Exam questions often describe a pressure reading during flow, then ask whether the system can maintain service. Pay attention to whether the problem includes friction loss, elevation change, or pump discharge pressure.
Elevation change matters
Pressure drops as water moves uphill and rises as water moves downhill. A service connection 46 feet higher than the tank reference point loses about 20 psi from elevation alone.
46 feet ÷ 2.31 = 19.9 psi
That is why hillside systems, pressure zones, and booster stations show up so often in distribution questions.
How to practice it
Work a few problems where you convert pressure to head, then a few where you convert head to pressure. After that, add one extra detail at a time: elevation, friction loss, pump discharge pressure, or tank level.
You can drill this style of question in the free water distribution practice set.