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In this article: weir, weir plate, portable

At Openchannelflow, we continually strive to make our products as easy as possible to use.  Ultimately we want you to think of them as appliances...something you can use without having to think about it.  We want you focused on your data, not how you collected that data.  To that end, we are continually tinkering, tweaking, rethinking how our customers use our products.  Recently our attention has been focused on our portable weir plates.

As we've discussed before, portable weir plates are a great way to stretch your research dollars.  Instead of custom designing and fabricated a weir plate for each installation or flow conditon, Openchannelflow has simplified the process by developing a standard weir carrier with four interchangeable weir plates.

Now our previous weir carrier was pefectly suited to the task:  it was percision cut and structurally strong.  The problem was it was also difficult to move around.  At 4' [121.92 cm] wide, we would call it luggable, not really portable.  This issue nagged at us and after listening to our customer's experiences in the field we decided something needed to be done.  The cheif complaints we hear were a need to improve portability and handling. 

our old weir carrier

To improve portability, we've extended the height of the carrier 3" [7.62 cm] to allow for handles on each side of the notch opening to be formed into the carrier.  Bringing the lift points over a foot [30.48 cm] closer together makes the carrier considerably easier to move.  To reduce the strain when moving the carrier long distances - and stop it from cutting into your fingers - we then applied a long life, cushioned neoprene edge trim on the upper portion of the handle cut-outs.  

To improve handling, we've gone back and rounded or chamfered all of the weir carrier edges.  The days of baning a squared off corner into your shin are gone!

Now the great thing about these changes is that we've been able to greatly improve the portability and handling of the set without affecting the usability, accuracy, or cost!  

portable weir carrier with Cipolletti weir plate mounted

Installation couldn't be simpler.  Simply  embed the weir plate carrier in your earthen channel, pick the weir that best fits the flow, and away you go - on to collecting data and whatever is next on your list!  

The modular nature of the set allows you fine tune your data collection.  If you need to go up or down a size, simply unbolt the weir plate from the weir carrier, select the size you need, and then bolt it on.  That’s all there is to it!  There's no need to remove the carrier from the channel and swapping out weir plates takes only a minute.

Weir Style Flow Rates
22 1/2 ° V 3.991 – 67.53 gpm [0.242 – 4.318 L/s]
45° V 8.309 – 143.4 gpm [0.5039 – 9.051 L/s]
90° V 20.07 – 346.5 gpm [1.217 – 21.86 L/s]
12-Inch [30.48 cm] Cipoletti 135.1 – 534.2 gpm [8.196 – 32.40 L/s]


A watertight seal between the weir plate and the carrier by a combination of mechanical force, neoprene gasketing, and self-sealing cap screws.  Any water that approaches the weir goes over it...not around it!

cushioned lift handle on weir plate carrier

Precision cut from high strength, corrosion resistant 304 stainless steel, Openchannelflow portable weir plate are designed for years of use in even the most rugged applications.  Should any part of the weir plate set fail, however unlikely, mass production allows for guaranteed one-to-one replacement.

intechangeable v-notch and Cipoletti weir plates

Over time wooden weirs will rot, swell, or decay.  This is particularly true at the crest of the weir where a wooden weir plate needs to be beveled so that the flow can spring from the weir face.  Aluminum, although light, is a relatively soft material and is susceptible to nicks and abrasions along the weir crest - not really something you want to throw in the bed of your pickup and haul around from site to site.  Finally, fiberglass, unless sufficiently reinforced, will want to bow in the direction of the flow – distorting the profile of the weir.

learn more about portable weir carriers with interchangeable weir plates

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