Can a Venturi flowmeter be used to measure flow from a centrifugal untreated wastewater pump that starts at 25 gal/min and has a maximum of 100 gal/min?

Can a Venturi flowmeter be used to measure flow from a centrifugal untreated wastewater pump that starts at 25 gal/min and has a maximum of 100 gal/min?

• A. Not sure
• B. Not applicable
• C. True
• D. False

Answer: (C)

Venturi flowmeters measure flow by creating a differential pressure across a constriction, using Bernoulli’s principle. They’re a rugged, no-moving-parts option for liquids and are commonly used in wastewater piping, provided the flow is within the meter’s calibrated range and the fluid isn’t so dirty that it causes excessive wear or fouling. In this case, the pump delivers between 25 and 100 gal/min. That range fits well within typical Venturi meter calibration, so it can be used to measure the flow. Just account for the realities of untreated wastewater—solids, air entrainment, and turbidity can affect pressure readings and wear—so proper installation, strainers or screens, adequate straight run, and regular maintenance/calibration are important. Overall, it is suitable to use a Venturi flowmeter for this pump.

Venturi flowmeters measure flow by creating a differential pressure across a constriction, using Bernoulli’s principle. They’re a rugged, no-moving-parts option for liquids and are commonly used in wastewater piping, provided the flow is within the meter’s calibrated range and the fluid isn’t so dirty that it causes excessive wear or fouling.

In this case, the pump delivers between 25 and 100 gal/min. That range fits well within typical Venturi meter calibration, so it can be used to measure the flow. Just account for the realities of untreated wastewater—solids, air entrainment, and turbidity can affect pressure readings and wear—so proper installation, strainers or screens, adequate straight run, and regular maintenance/calibration are important. Overall, it is suitable to use a Venturi flowmeter for this pump.