Washington DC 3rd Class Boiler Practice Test

Static pressure is the pressure in the fluid that acts equally in all directions and is not due to the fluid’s motion. A reading taken from the center of the impeller to the gauge measures the pressure energy at that point without including the energy from the fluid’s velocity, so it reflects static pressure. Dynamic pressure, on the other hand, comes from how fast the fluid is moving and would require a measurement that isolates velocity head, such as a Pitot tube. Total pressure would be the sum of static and dynamic pressures, which again isn’t what this tap provides. Gauge pressure is just static pressure expressed relative to atmospheric pressure, so in this context the reading is best described as static (often observed as gauge) pressure.