The velocity pressure recorded by a pitot tube and gauge is which type of pressure?

• A. Flow
• B. Static
• C. Normal-operating
• D. Atmospheric

Answer: (A)

Dynamic pressure is the pressure caused by the movement of the liquid, not the pressure due to being at rest. A pitot tube facing the flow measures stagnation (total) pressure, and a static port measures the static pressure. The velocity pressure, or dynamic pressure, is the difference between those two readings, and it represents the pressure component that arises from the flow itself. In fire service terms, this dynamic portion of pressure is what is referred to as flow pressure, since it’s the pressure related to how fast the water is moving through the line. Therefore the velocity pressure recorded by a pitot tube and gauge is flow pressure, not static, atmospheric, or normal-operating pressure.