Flumes and Weirs Parshall, Palmer-Bowlus, H-Type, Trapezoidal, and Cutthroat

Flumes and Weirs Flowmeter

Flumes and weirs are designed to force a transition from sub-critical to super-critical flow. In the case of many flumes, the transition is caused by designing flumes to have a narrowing at the throat and a drop in the channel bottom. Such a transition causes flow to pass through critical depth in the flume throat. At the critical depth, energy is minimized and there is a direct relationship between water depth ,velocity and flowrate. many types of weirs and Flumes exist now but their primary function is to give us an indication of flowrate. www.eesiflo.com

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Featured Flumes and Weirs Flowmeter Suppliers

Accura-Flo^TM Parshall flumes
The Parshall flume was developed by the U.S. Soil Conservation Service in the 1920's to measure irrigation water flow. Its principle advantages include low head loss, self cleaning capability, and its ability to withstand relatively high degrees of submergence without affecting the rate of flow. Parshall flumes are best used in channels having rectangular cross-sections. More>>

Parshall Flumes
The Parshall flume is one of a large class of open channel primary elements known as critical flow venturi flumes. A distinguishing characteristic of the Parshall flume is the downward sloping invert of the throat. This feature gives the Parshall flume its ability to operate at higher ratios of downstream to upstream head than any other such device. More>>

The Palmer-Bowlus Flume
Warminster Fiberglass makes both Palmer-Bowlus and Parshall Flumes. They are used to measure flows in open channels and pipelines. Both types are precision molded of fiberglass reinforced polyester for light weight and corrosion resistance.They both are available with a smaller flume "nested" inside, as shown in the above Parshall Flume (on the right). More>>

Featured Flumes and Weirs Flowmeter Products

Eesiflo Easz-11 Open Channel Flow Meter

Flumes and Weirs - Most types
21 point linearisation
Plug in terminals
Ease of lnstallation and Configuration
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Flow by a Non Contact method

The common method of measuring flow through an open channel is to measure the height or HEAD of the liquid as it passes over an obstruction (a flume or weir) in the channel. Using ultrasonic level technology, Eesiflo open channel flow meters include a non-contacting sensor mounted above the flume or weir. By measuring the transit time or time of flight from transmission of an ultrasonic pulse to receipt of an echo, the water level or "Head" is accurately measured.

Flumes and weirs are specially designed channel shapes that characterize the flow of water. Common types are Rectangular Weirs, V-Notch Weirs, Parshall flumes and Palmer Bowlus flumes. The choice of flume or weir type depends on the application: flow rate, channel shape and solids content of the water. Contact Eesiflo for advice on selection of a suitable flume or weir for your application.

Eesiflo open channel flow meters can be calibrated to any flume or weir by menu selection. Calibration to uncommon or custom flumes are also possible. Eesiflo also offers a PC software program to set up and monitor measurements.

Eesiflo open channel flow meters include a non-contacting ultrasonic sensor, connecting cable and an electronics enclosure which can be mounted at a convenient location nearby (within 500 ft / 152 m). The instruments display, totalize, transmit and control. We can also package complete systems to your various needs.

Methods for flow measurement are described in detail in international standards, national standards, association standards and numerous hydraulic textbooks and handbooks. Some of the most used standardization organizations are:

the International Organization for Standardization (ISO)

the American Society for Testing and Materials (ASTM)

the American Society of Mechanical Engineers (ASME)

the British Standards Institute (BSI)

the National Institute for Science and Technology (NIST)

ASTM Flow Standards - the American Society of Mechanical Engineers

ASTM D 5242 - STANDARD TEST METHOD FOR OPEN-CHANNEL FLOW MEASUREMENT
OF WATER WITH THIN-PLATE WEIRS

ASTM D 5614 - STANDARD TEST METHOD FOR OPEN CHANNEL FLOW MEASUREMENT
OF WATER WITH BROAD-CRESTED WEIRS

ASTM D 5640 - STANDARD GUIDE FOR SELECTION OF WEIRS AND FLUMES FOR
OPEN-CHANNEL FLOW MEASUREMENT OF WATER

ASTM D 5716 - STANDARD TEST METHOD FOR MEASURING THE RATE OF WELL
DISCHARGE BY CIRCULAR ORIFICE WEIR

AWWA Flow Standards - the American Water Works Association
AWWA C909 - MATCHED-DIE-MOLDED, FIBERGLASS-REINFORCED PLASTIC WEIR
PLATES, SCUM BAFFLES, AND MOUNTING BRACKETS
AWWA F102 - MATCHED-DIE-MOLDED, FIBERGLASS-REINFORCED PLASTIC WEIR
PLATES, SCUM BAFFLES, AND MOUNTING BRACKETS

BS Flow Standards - the British Standards Institute
BS 3680 P4A - METHOD USING THIN-PLATE WEIRS
BS 3680 P4B - TIANGULAR PROFILE WEIRS
BS 3680 P4E - RECTANGULAR BROAD-CRESTED WEIRS
BS 3680 P4I - V-SHAPED BROAD CRESTED WEIRS
BS 3680-4F - ROUND NOSE HORIZONTAL BROAD-CRESTED WEIRS
BS ISO 4377 - HYDROMETRIC DETERMINATIONS - FLOW MEASUREMENT IN OPEN
CHANNELS USING STRUCTURES - FLAT-V WEIRS

DIN Flow Standards - Deutsches Institut f?r Normung eV
DIN 19558 - SEWAGE TREATMENT PLANTS; WEIR AND SCUM BAFFLE;
ARRANGEMENT, MAIN DIMENSIONS AND OVERFLOW RATE

GOST Flow Standards - Russian Federation
GOST R 51657.4 - WATER FLOW MEASUREMENT IN HYDROMELIORATION AND WATER
SUPPLY SYSTEMS. WATER DISCHARGE MEASUREMENT IN OPEN CHANNELS BY
TRIANGULAR PROFILE WEIRS. GENERAL TECHNICAL REQUIREMENTS

ISO Flow Standards - International Organization for Standardization
ISO 1438/1 - WATER FLOW MEASUREMENT IN OPEN CHANNELS USING WEIRS AND
VENTURI FLUMES - PART 1: THIN-PLATE WEIRS
ISO 3846 - LIQUID FLOW MEASUREMENT IN OPEN CHANNELS BY WEIRS AND
FLUMES - RECTANGULAR BROAD - CRESTED WEIRS
ISO 3847 - LIQUID FLOW MEASUREMENT IN OPEN CHANNELS BY WEIR
ISO 4360 - LIQUID FLOW MEASUREMENT IN OPEN CHANNELS BY WEIRS
ISO 4362 - MEASUREMENT OF LIQUID FLOW IN OPEN CHANNELS TRAPEZOIDAL
PROFILE WEIRS
ISO 4374 - LIQUID FLOW MEASUREMENT IN OPEN CHANNELS - ROUND-NOSE
HORIZONTAL BROAD-CRESTED WEIRS
ISO 4377 - HYDROMETRIC DETERMINATIONS - FLOW MEASUREMENT IN OPEN
CHANNELS USING STRUCTURES - FAT-V WEIRS
ISO 8333 - LIQUID FLOW MEASUREMENT IN OPEN CHANNELS BY WEIRS
ISO 9827 - MEASUREMENT OF LIQUID FLOW IN OPEN CHANNELS BY WEIRS AND
FLUMES - STREAMLINED TRIANGULAR PROFILE WEIRS

SAA Flow Standards - Standards Australia
SAA AS 3778.4.1 - MEASUREMENT USING FLOW GAUGING STRUCTURES -
THIN-PLATE WEIRS
SAA AS 3778.4.2 - MEASUREMENT USING FLOW GAUGING STRUCTURES -
RECTANGULAR BROAD- CRESTED WEIRS
SAA AS 3778.4.3 - MEASUREMENT USING FLOW GAUGING STRUCTURE -
ROUND-NOSE HORIZONTAL BROAD-CRESTED WEIRS
SAA AS 3778.4.4 - MEASUREMENT USING FLOW GAUGING STRUCTURES -
V-SHAPED BROAD-CRESTED WEIRS
SAA AS 3778.4.5 - MEASUREMENT USING FLOW GAUGING STRUCTURES -
TRIANGULAR PROFILE WEIRS
SAA AS 3778.4.6 - MEASUREMENT USING FLOW GAUGING STRUCTURE - FLAT-V
WEIRS

TAPPI Flow Standards
TAPPI TIP 0410-10 - WEIRS AND FLUMES

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