Made of fiberglass reinforced plastic (FRP), Plasti-Fab Flumes provide optimum corrosion resistance. Available in a wide range of functional designs and custom sizes, there's a Plasti-Fab flume for your specific need. For extremely severe effluents, they're also available in Vinyl Ester, stainless steel, or other special materials as required. Our representatives and engineering staff can assist you in identifying the perfect flume for your need.

Characteristics common to all flumes:

Accurate, Economical, Long Lasting - Fiberglass flumes are more rugged and cost less than stainless steel flumes, and they are more durable than concrete or galvanized flumes.

Rugged Construction - Most Plasti-Fab flumes are built with minimum 2" end and top flanges. Top spreaders are factory installed. Lightweight laminated foam ribs with a large cross section limit wall and floor deflection better than embedded angles. Smooth White Gelcoat Surfaces minimize buildup of silt and organic debris, aid in reading the gage and instrument calibration, and make cleaning easier.

Easy Installation - Plasti-Fab flumes are heavily ribbed and braced for better dimensional stability and are equally effective as free-standing installations or as liners in concrete.

Flume Accessories and Instrument Setups:

• Adjustable Stainless Steel Brackets For 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
  - 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
• Hb Head Gage for Submerged Flow Monitoring
• Sealed Ultrasonic Mounting Tube
• FRP Grating
• FRP Flume Covers

  
  
  Also Available:

• Pipe stubs for direct pipe connection using caulking collars, neoprene boots or slip flanges.
• Free standing flumes with inlet and outlet bulkheads for larger diameter pipes and channels.
• Flared Inlet Transitions to smooth entering flow from larger diameter pipes and channels.
• Nested Flumes for planned future expansion or downsizing.
• Packaged Metering Manholes - from 4" to 72" throat size.
• Tranquilizer Racks or Energy Absorbing units to reduce velocity and turbulence.
• Surge Boxes to handle possible surcharging at in-plant and sensitive locations - from 4" to 24" throat size.
• Sectioned Flumes to resolve access problems in existing structures.
  

Parshall

Link: Plasti-fab.com

Used in monitoring sewage, plant effluent, storm water and irrigation water the Parshall flume is still the best known and most widely used for permanent installations. It is available in throat sizes from 1" to 12 feet. These flumes are available with numerous accessories and adaptations to match your flow and installation requirements.

Made of fiberglass reinforced polyester (FRP) Plasti-Fab flumes offer optimum corrosion resistance and are the industry leader in measuring flow. For extremely severe industrial effluents they are also available in Vinyl Ester, stainless steel or other special materials as needed.

Download Literature

 

* Flow Range is based on meter capability, free board allowances and flow studies. Peak flow range can vary due to pipe or channel scope. I.D. material of constructon and hydraulic consideration.

Palmer Bowlus

Link: Plasti-fab.com

The Palmer-Bowlus flume is well know in the sanitary field, and has been used in the Los Angeles area for over 60 years. It's primary application is in pipelines, in round bottom channels or in manholes where it is often preferred because of cost and ease of installation that can minimize construction expense.

Download Literature

Trapezoidal

Link: Plasti-fab.com

Originally 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 flumes fall into two principal groups, 60° V-notch flumes and larger trapezoidal flumes. The 60° V-notch 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.

Download Literature

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.
• 60° V 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.

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

Link: Plasti-fab.com

H flumes are well known by soil and agricultural agencies that have used them to monitor field runoff and study water shed drainage. For the past 20 years Plasti-Fab H flumes have been successfully used in the sanitary field to measure storm water, effluent and sewage streams having very broad flow ranges that otherwise would be difficult or impossible to measure in other types of flumes.

The H flumes and related HS & HL flumes are gaining popularity due to their ability to handle wide ranging flows that can vary by as much 100:1 or more from low to peak. Because of the unique throat, which resembles a weir in some respects, the H flumes provide excellent resolution at low flows and still have capacity to capture peak flow readings on many 15 to 25 year storm events.

Download Literature

Flow Characteristics:
H flumes have a flat floor that must be installed level with the approach section or entrance channel. Flow must be able to free fall or spill from the end of the flume in an unimpeded manner. H Flumes are more tolerant of slope and velocity than any other style of flume. Complete flow charts for each size flume exist, but simplified flow equations are not readily available.

The wall height and configuration of the throat denote flume size. HS Flumes have a more restrictive outlet orifice to increase low flow resolution, and are used on small flow streams. H flumes cover the mid-range up to about 53 MGD. The HL flume spreads the throat opening slightly and can measure flows as high as 74 MGD.

The H flumes will normally be preceded by a rectangular approach channel that is approximately the same width and depth as the flume, and a minimum of 3-5 times the flume height. Approach sections are available from Plasti-Fab, and these can be adapted for connection to a pipe.

H-Flume	Flow Range - GPM
.4 HS	1-30
.5 H	1 -115
.6' HS	1-80
.8' HS	1 - 175
.75 H	1 - 350
1.0 HS	1 - 305
1.0 H	2 - 720
1.5 H	2 - 1,580
2.0 H	5 - 3,640
2.5 H	5 - 6,780
3.0 H	5 - 11,175
3.0 HL	5 - 20,950
4.5 H	5 - 28,675
4.0 HL	10 - 38,550

Download Literature

Download Manhole Application Form

Standard Options:

• 
  Built to meet the requirements of ANSI/ASTM D-3753 "Standard specifications for fiber-reinforced manholes.
• Integral Parshall or other flume for flow measurement
• Top cover or manhole reducer
• End adapters for quick connection to pipe
• Internal ladder
• Mounting brackets for flow sensors and other monitoring equipment

Choice of Cover:

• Light weight 48" or 60" diameter hinged fiberglass cover with hasp for locking.
• Concentric 24" or 30" diameter manway reducer for use with steel cover suitable for H-20 highway loading.
• Concentric 24" diameter reducer with aluminum watertight (gas tight) lid for non-traffic loads.

Fiberglass Barrel:

• 48", 60" or 72" diameter barrels.
• Watertight - one piece construction with FRP bottom completely seals manhole and eliminates infiltration.
• Lightweight - weighs less than 10% of a comparable concrete structure to permit fast easy installation.
• Corrosion resistant - extremely resistant to numerous chemicals, salt water, corrosive soil conditions, ground water and electrolysis.
• Strong and very durable - built to meet structural requirements of ASTM D-3753.
• Smooth white interior gel coat finish provides a clean, bright work space inside the manhole.
• Self Contained Flow Measurement and Monitoring Capability
• Normally supplied with an integral FRP Parshall or Palmer-Bowlus flume. Other flumes and flow devices may be used including Cutthroat, Trapezoidal, H-flumes, Weirs or closed pipe meters.
• Mounting brackets or sensor cavities are available for all types of flow meters and other monitoring equipment such as sampling, pH, conductivity and temperature.

Convenient Features and Accessories:

• FRP ladder is provided on units over 4 ft. Deep.
• Top of flume may be covered with FRP grating.
• Shelf, bracket or hook for mounting flow meter, or other equipment may be provided.
• Utility taps for convenient sub-grade hook-ups, or above grade enclosures for meters and samplers are available.
• Vents, safety rail, harness and other OSHA safety devices can be factory installed.

End Adapters For Pipe:

• 
  FRP pipe stubs with flexible water-tight neoprene connecting boots are provided. Neoprene boot is attached with stainless steel clamping bands to provide an easy to install connection.
  Cost Saving to Install. One piece construction assures that the flume and flow monitoring package are set up correctly. The light weight manhole with simple pipe connection helps to reduce the time and cost of installation.