What is measured as a differential pressure drop in the throat of the venturi?

What is measured as a differential pressure drop in the throat of the venturi?

• A. Total steam flow rate
• B. Boiler pressure
• C. Condensate level
• D. Fuel flow rate

Answer: (A)

A venturi works on the idea that narrowing the pipe creates a change in velocity and pressure. As the fluid speeds up through the throat, its static pressure drops. The difference between the upstream pressure and the throat pressure—measured as a differential pressure—is directly related to how much fluid is flowing. In steam lines, that pressure drop is used to determine the total steam flow rate through the venturi, because the differential is tied to the velocity and thus the volume of steam moving through the meter. The other options aren’t what the venturi differential measures: boiler pressure is read with a pressure gauge, condensate level is tracked with level devices, and fuel flow rate is measured with a separate flow meter on the fuel line. The venturi’s differential pressure specifically provides the total steam flow rate.

A venturi works on the idea that narrowing the pipe creates a change in velocity and pressure. As the fluid speeds up through the throat, its static pressure drops. The difference between the upstream pressure and the throat pressure—measured as a differential pressure—is directly related to how much fluid is flowing. In steam lines, that pressure drop is used to determine the total steam flow rate through the venturi, because the differential is tied to the velocity and thus the volume of steam moving through the meter.

The other options aren’t what the venturi differential measures: boiler pressure is read with a pressure gauge, condensate level is tracked with level devices, and fuel flow rate is measured with a separate flow meter on the fuel line. The venturi’s differential pressure specifically provides the total steam flow rate.