Broad Crested Weir
Product Code : EL-EFFCA-11070
Quick answer: The broad crested weir is a PVC cuboid weir body for the Lab Exports experimental flume. With two add-on elements its sharp edges become rounded, so students can compare how edge shape changes the nappe, study free and submerged overfall and find the discharge coefficient with a level gauge. Lab Exports manufactures it in Delhi for engineering colleges, polytechnics and TVET institutes.
Specifications
| Item | Specification |
|---|---|
| Weir body | PVC, cuboid, sharp edges, with sealing lips |
| Additional elements | 2 nos., for creating rounded edges |
| Weir body dimensions (L x W x H) | 260 x 96 x 120 mm |
| Weight | Approx. 5 kg |
How the broad crested weir experiment is done
A broad-crested weir is long enough in the flow direction for the streamlines over it to become parallel, so the flow on the crest passes through critical depth, yc = 2/3 of the upstream head H. That gives the discharge from one head reading: Q = Cd * b * sqrt(g) * (2H/3)^1.5, or about 1.705 * Cd * b * H^1.5 in SI units. Real weirs lose some energy at the upstream edge, and Cd shows how much.
With the sharp-edged body the flow separates at the upstream corner and a small eddy forms on the crest. Fitting the rounded elements removes most of that separation, and the measured Cd rises. Raising the tailwater until it drowns the crest shows the change from free to submerged overfall.
- Fit the weir body in the flume, sharp-edged first.
- Set a discharge and let the flow settle.
- Measure the head upstream of the weir with a level gauge and read the flow rate.
- Repeat for several discharges, then fit the two rounded elements and repeat.
- Plot Q against H^1.5 for both edge shapes and compare Cd with theory.
Key features
- Cuboid PVC weir body with sharp edges and sealing lips
- Two add-on elements convert the sharp edges to rounded ones
- Shows free and submerged overfall on the same weir
- Makes the effect of edge shape on the nappe visible through the flume glass
- Used with a level gauge to find discharge and discharge coefficient
Documentation and supply
Most Lab Exports products carry a one-year manufacturer warranty.
Lab Exports manufactures the broad crested weir at its works in Laxmi Nagar, Delhi, and supplies it to engineering colleges, polytechnics and TVET institutes in India and 60+ countries, handling the export documents for each shipment. More about the company is on the About Lab Exports page.
Related Experimental Flume Flow Channel Apparatus products
- Extension Element of the Experimental Flume (EL-EFFCA-11069)
- Pitot Static Tube (EL-EFFCA-11071)
- Set of Plate Weirs, Four Types (EL-EFFCA-11068)
- Velocity Meter (EL-EFFCA-11072)
- Venturi Flume (EL-EFFCA-11066)
- Ogee-Crested Weir with Pressure Measurement (EL-EFFCA-11065)
The full range is in the Experimental Flume Flow Channel Apparatus section of the Engineering Lab range.
Frequently asked questions
What does the broad crested weir demonstrate?
It demonstrates free and submerged overfall and how a sharp or rounded upstream edge changes the flow over the crest and the discharge coefficient.
How are the rounded edges fitted?
Two additional elements fix to the cuboid weir body to turn its sharp edges into rounded ones.
What is the price of the broad crested weir?
Prices are not published on the website. Add the broad crested weir to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code EL-EFFCA-11070 and the quantity, to receive a quotation.
Does Lab Exports manufacture the broad crested weir?
Yes. Lab Exports manufactures the broad crested weir at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code EL-EFFCA-11070.
Request a quote
Email [email protected] with the house code EL-EFFCA-11070 and the quantity, or add the broad crested weir to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.
