Advantages of Open Channel Flow Metering Elements Manufactured by Free
Flow
Parshall flumes:
Available in a wide range of sizes and flow capacities
Very widely used and well accepted by regulatory authorities
Low head loss
Self scouring design
Can be used in submerged flow conditions
Presence of submerged flow conditions easily determined
Head loss calculation tables available
Discharge tables and formulas standardized
Palmer-Bowlus Flumes:
Easily adapted to pipeline flow measurement
Compact size
Wide range of pipe sizes available
Trapezoidal 60 Degree V Notch Throat Flumes:
Good low flow resolution
Compact size
Rectangular Cutthroat flume:
Flat bottom for low head loss
Discharge tables and formulas standardized
H flumes:
Most often used in agricultural runoff measurement applications
Available in a wide range of flow sizes
V shaped outlet gives good resolution at low flows
Discharge tables and formulas standardized
V Notch Weirs:
Most often used for high accuracy flow measurement
Good for very low flow applications
Self scouring design
Metering Manholes
Reduces metering station installation costs
Quick installation
Any small to medium sized flow element available in metering manhole
