PARSHALL FLUMES

Parshall flumes are hydraulic measurement elements used for flow measurement and flow control in open channel flows.
Overview

Parshall flumes are hydraulic measurement elements used for flow measurement and flow control in open channel flows. They enable high accuracy and continuous measurement of water flow in wastewater treatment plants, channel lines or surface water inlets. The flume consists of a channel structure that narrows at certain geometric ratios. This geometry increases the speed of water, creating a hydraulic jump (venturi effect), and the amount of flow passing through the water level can be calculated with standard calibration curves. Parshall flumes produced by our company are manufactured from stainless steel (AISI 304 / 316) and HDPE (PE100) materials and meet the highest quality standards in terms of both durability and longevity.

WORKING PRINCIPLE

The Parshall flume consists of three sections: inlet (convergent), throat and outlet (divergent). As water flows through this narrowing-transition structure, the speed increases in the throat section and the water level drops. This velocity-level change forms the basis of flow calculation. An ultrasonic level sensor or pressure sensor placed on the flume continuously measures the water height (Hₐ). This level value is proportional to the calibration curves (Q = K × Hⁿ) defined according to the Parshall flume standard. In this way, the system can calculate the instantaneous or total flow (m³/hour, m³/day) value. If desired, the flume can work integrated with an automatic flow measurement panel and data logger.

DESIGN FEATURES

1. Material Options
AISI 304 / 316 Stainless Steel
  • High chemical resistance, rigid and long-lasting structure

  • Preferred in outdoor environments, industrial lines and aggressive environments

  • Welded and bolted mounting options available

HDPE (PE100)
  • Lightweight, corrosion-free and maintenance-free structure

  • Easily integrated into reinforced concrete channels or polyethylene lines

  • Leak-proof connection is made with ultrasonic welding or thermofusion


2. Standard Sizes

Parshall flumes are produced in different throat widths according to flow range. All sizes comply with ISO 9826 / ASTM D1941 standards.

SizeThroat WidthFlow RangeLengthHeight
1"25 mm0.0005 – 0.003 m³/s450 mm150 mm
3"75 mm0.002 – 0.020 m³/s600 mm200 mm
6"150 mm0.010 – 0.100 m³/s900 mm300 mm
9"225 mm0.030 – 0.250 m³/s1100 mm400 mm
12"300 mm0.060 – 0.400 m³/s1300 mm500 mm
18"450 mm0.150 – 1.000 m³/s1600 mm700 mm
24"600 mm0.250 – 2.000 m³/s1900 mm900 mm

3. Structural Features
  • Three-part modular structure (inlet – throat – outlet)

  • Smooth transitions and laser cutting tolerances on inner surfaces

  • Flanged or anchored connection points

  • Special sensor platform or bracket for level measurement

  • Optional inlet screen and sediment discharge valve


4. Mounting Types
  • Anchored mounting inside reinforced concrete channel

  • Welded (butt-fusion) connection inside HDPE line

  • Flanged type module as portable measurement point

ADVANTAGES

Accuracy:

±2% measurement precision (with calibrated sensor)

Maintenance-free design:

Contains no moving parts

Corrosion resistance:

Long life thanks to stainless or HDPE body

Easy installation:

Lightweight, compact and field-compatible structure

Automation integration:

SCADA connection with ultrasonic or pressure sensor

Fixed geometry:

Long-term stable measurement without requiring calibration

Economic solution:

Low investment cost in open channel flow measurement

Standardized models:

All sizes from 1"–48" can be produced from stock

APPLICATION AREAS

Municipal wastewater treatment plants (inlet and outlet flow measurement)

Industrial treatment lines and process water systems

Regulation stations, surface water channels

Irrigation water and drainage lines

Laboratory and pilot scale treatment systems

Flowmeter calibration channels

Continuous monitoring systems at discharge points according to SKKY and ISO 5667

SENSOR AND AUTOMATION INTEGRATION

Parshall flumes can be used together with ultrasonic level meters, pressure sensors or radar sensors. Sensor data is transferred to the control panel or SCADA system; instantaneous flow (Q), total flow (ΣQ) and level (H) values can be monitored on the software. If desired, the system can be equipped with remote monitoring and automatic reporting features with a data logger or GSM modem.

Conclusion

Parshall flumes are standard hydraulic equipment that enable reliable, economical and long-lasting measurement of open channel flows. Models produced by our company fully meet the needs of modern facilities with stainless steel and HDPE material options, precise manufacturing tolerances and automation compatibility. Thanks to their corrosion-resistant structures, easy installation features and high measurement precision; our Parshall flumes are used as the most reliable solution for accurate flow measurement in municipal and industrial facilities.