BAT Water System Hydraulics & Pressure Principles Flashcards

What is the typical minimum inlet supply pressure required for a reduced pressure zone (RPZ) assembly to operate correctly?

Answer: 10 psi

An RPZ assembly requires a minimum of 10 psi inlet pressure to ensure the relief valve and check valves function as designed.

What does 'static pressure' refer to in a water distribution system?

Answer: Pressure in the system when no water is flowing

Static pressure is the pressure present in a system when there is no flow, representing the stored potential energy of the water.

How does elevation affect water pressure in a distribution system?

Answer: Pressure decreases as elevation increases

Water pressure decreases by approximately 0.433 psi for every foot of elevation gain due to the reduced weight of the water column above.

What is the primary purpose of a differential pressure gauge during backflow assembly testing?

Answer: To determine the pressure difference across check valves or the relief valve

A differential pressure gauge measures the pressure difference between two points, which is critical for evaluating check valve tightness and relief valve opening.

According to Bernoulli's principle, what happens to fluid pressure as its velocity increases in a pipe?

Answer: Pressure decreases

Bernoulli's principle states that as fluid velocity increases, static pressure decreases, which is the basis for understanding backsiphonage risk.

What unit is 'head pressure' most commonly expressed in within US water system calculations?

Answer: Feet of water column

Head pressure in US water systems is typically expressed in feet of water column, where 2.31 feet of water column equals 1 psi.