Cutthroat Flumes

This flume is similar to the Parshall Flume except that the parallel throat section is removed and the bottom is at the same elevation as the channel invert through the length of the flume. Being a "zero" throat flume the range of accuracy or useable depth for the Cutthroat Flumes is directly related to length of the flume. The Cutthroat Flume is commonly used for flow splitting, but is not recommended for flow measurement.

Cutthroat Flume Advantages:

• The Cutthroat Flume is an easy flume to construct, and flow tables are available for a number of standard sizes.
• All flume dimensions are proportional and can be increase or decrease as required to satisfy special application requirements.
• The flat bottom allows the flume to be easily placed into existing channel with reduced excavation or construction cost.
• The absence of a raised or descending throat section helps to reduce the upstream pool depth.
• Two or more Cutthroat Flumes installed parallel to one another can be used very effectively for flow proportioning. This is common at the entrance to rectangular basins, lagoon diversion structures, raceways and other places where one flow stream must be split into two or more equally divided streams.

Cutthroat Flume Disadvantages:

• Changes in channel width relative to the throat width and overall flume length can affect the accuracy of flow readings, particularly in the higher flow ranges.
• The addition of inlet flow transition walls to smooth entrance or exit conditions can inadvertently change the flow equation, thereby reducing accuracy.
• Much of the work done on Cutthroat Flumes was directed at developing a flume that would operate satisfactorily under both free flow and submerged flow conditions. However, free flow is the recommended operating mode since measuring and recording instruments for submerged flow are not readily available.

Problem Solving Adaptations:

• Permanent installation in concrete or earthen channels.
• Free standing flumes
• H_a head gage – permanently molded into the side of the flume
• Nested flumes for planned future expansion or downsizing
• Packaged Metering Manholes for below grade installation
• "Magic Bottoms" to cure submergence or leveling problems
• Tranquilizer racks or energy absorbing units to reduce turbulence or velocity.

Other Accessories and Instrument Setups:

• Adjustable stainless steel support brackets for all typed of ultrasonic transducers
• Molded side cavities and floor cavities for:
Stainless steel bubble pipes
Stainless steel sample pipes
Pressure transducers
Capacitance probe and s/s grounding plates
pH probes

• Stainless steel liftout brackets for pressure and pH probes
• 2" threaded tap for remote still well
• 8" and 12" diameter attached still wells
• H_b head gage for submerged flow monitoring

Request a Quote for Cutthroat Flumes