corrosion resistant equipment for wastewater control
TRAPEZOIDAL FLUMES
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pdfbrochOriginally developed for irrigation, trapezoidal flumes have proven their effectiveness during years of use by the Soil Conservation Service and Department of Agriculture - both to monitor flows in furrows and in sloping irrigation ditches. Today their inherent advantages are making trapezoidal flumes increasing popular for industrial and municipal applications, particularly where low flow measurement is required.

   
 
 
Trapezoidal Flume 2
Large 60º V Trapezoidal Flume

Trapezoidal Flumes
Flow Range - GPM
Sm. 60º V
1 - 30
Lg. 60º V
1 -120
XL 60º V
1 - 600
3.0' 60º V
2 - .6,200
2" - 45º WSC
40 - 980
12" - 45º SRCRC
100 - 2,955
18" - 45º TRAP
75 - 14,530
2.0' SRCRC
320 - 21,970


Trapezoidal Flume 2

Lg. 60º Trapezoidal Flume with
surge box and cover

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Trapezoidal Flume 2

2"- 45º WSC Trapezoidal Flume

  Trapezoidal flumes fall into two principal groups, 60º V-notch flumes and larger trapezoidal flumes. The 60º V flumes have a sharp V-throat section similar to a V-notch weir and produce superior resolution for accurate flow measurement down to 1 gpm. The larger trapezoidal flumes, up to the 2 ft. SRCRC flume, have flat floors and sloping sidewalls and can handle flows up to 32 MGD.

All Trapezoidal flumes exhibit similar flow characteristics, and have application advantages over other flumes and weirs.

  • The bottom is flat from entrance to exit for better head conservation.
  • Trapezoidal flumes do not require a free-fall discharge to operate correctly.
  • The staff gage and instrument mounting brackets are located within the flume and are factory installed.
  • The natural shape of the flume mimics many earthen and concrete-lined ditches. Little or no transition is required in these situations.

60°V Trapezoidal flumes provide the only practical means of obtaining good flow data on low and intermittent flow streams. This flume produces more readable head under 10 gpm than any other flume or weir. Plasti-Fab has demonstrated the flumes effectiveness in over 20 years of use by small industries, developments, parks and communities.

  • Accurate flow measurement down to 1 gpm.
  • Better resolution and repeatability especially below 0.2 ft. of head.
  • No requirement for upstream pooling or downstream free-fall.
  • Can operate up to 80 – 85 percent submergence with little or no loss of accuracy.
  • The flat floor and sloping wall allows solids to pass through the throat without being trapped.
  • 60º flume sizes are available to measure flows as high as 6200 gpm.

Larger Trapezoidal flumes have a primary gage located at the H1 location for normal free flow operation, and a downstream gage at the H4 location for use in conjunction with submerged flow tables.

We recommend that all flumes be designed and installed for free flow operation.

Problem Solving Adaptations:

  • Permanent installation in concrete or earthen channels
  • Free standing flumes with wing walls, end bulkheads or adapters for larger diameter pipes and channels.
  • End adapters for piped installation – Small 60º V to 3 ft. 60º V flumes.
  • Packaged Metering Manholes for below grade installation – Large 60º V to 3 ft. 60º V flumes.
  • Tranquilizer Racks and Energy Absorbing units to reduce velocity and turbulence.
  • Surge Boxes to handle possible surcharging at in-plant and sensitive locations –Large 60º and XL 60º V trapezoidal flumes.
  • FRP Grating or Odor Control Covers.

Accessories and Instrument Setups:

  • Adjustable stainless steel Support Brackets for all types of ultrasonic transducers.
  • Molded Side Cavities and Floor Cavities for:
        Stainless steel bubble pipes
        Stainless steel sample pipes
        Pressure transducers
        Capacitance probes and s/s grounding plates
  • Stainless steel Liftout Brackets for pressure and pH probes.
  • 2" threaded Tap for remote still well.
  • 8" and 12" diameter attached Still Wells.
  • Sealed Ultrasonic Mounting Tube.
 
  
 
    
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