Overview
ASTM D5390-21 is the internationally recognized standard test method for measuring open-channel flow of water and wastewater using Palmer-Bowlus flumes. Developed by ASTM International, this standard is widely used in the water industry for accurate volumetric flowrate determination in sewers and other open channels. Palmer-Bowlus flumes are particularly well-adapted for both permanent and temporary installations in circular sewer pipes, accommodating diameters from 4 inches to 6 feet (0.1 to 1.8 meters). With proper design and operation, these flumes can provide precise measurements while introducing minimal head loss and effectively passing sediment and debris.
Key Topics
- Scope of Application: Applicable to the measurement of water and wastewater flows in open channels and sewers using Palmer-Bowlus flumes. Essential for both temporary and permanent installations.
- Units of Measurement: The method uses inch-pound units as the primary standard, with SI conversions provided for informational purposes.
- Flume Design: Focuses on the selection, configuration, and installation of Palmer-Bowlus flumes based on channel or pipe size and other hydraulic conditions.
- Head and Flow Measurement: Outlines the relationship between upstream head and volumetric flowrate, ensuring reliable measurements through proper calibration and monitoring.
- Instrumentation: Discusses the use of primary instruments (the flume itself) and secondary instruments (depth/head measuring devices), including manual and automated sensors such as scow-type floats, pressure sensors, acoustic sensors, and electrical probes.
- Installation Guidelines: Emphasizes critical factors like channel approach conditions, avoidance of downstream submergence, maintaining a level installation, and effective sealing of the flume within the channel.
- Calibration and Quality Control: Recommends in-place system calibration for highest accuracy, with detailed procedures for validating both the primary flume and secondary measurement systems.
- Error Estimation: Addresses sources of error due to installation, instrumentation, and environmental variability, providing guidance to estimate and minimize measurement uncertainty.
Applications
- Wastewater Flow Monitoring: Widely used in municipal and industrial wastewater systems to monitor and control flows in circular sewer lines.
- Regulatory Compliance: Provides standardized methods for reporting and verifying flowrates in line with regulatory requirements for discharge and treatment.
- Environmental Monitoring: Supports environmental impact assessments by allowing accurate measurement of streamflow in open channels and outfalls.
- Sewer System Management: Essential tool for ongoing maintenance, troubleshooting, and capacity planning in water infrastructure.
- Temporary Flow Measurement: Suitable for short-term flow monitoring during system modifications, construction projects, or initial plant startups.
- Research and Development: Useful in hydraulic laboratories and field studies for modeling open-channel flow behaviors.
Related Standards
The use of ASTM D5390-21 is supported by and often referenced alongside other key standards in open-channel flow measurement, including:
- ASTM D1129: Terminology Relating to Water
- ASTM D1941: Open Channel Flow Measurement of Water with the Parshall Flume
- ASTM D2777: Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
- ASTM D3858: Open-Channel Flow Measurement of Water by Velocity-Area Method
- ASTM D5242: Open-Channel Flow Measurement of Water with Thin-Plate Weirs
- ISO 4359: Liquid Flow Measurement in Open Channels-Flumes
- ISO 555: Liquid Flow Measurements in Open Channels-Dilution Methods for Measurement of Steady Flow
- ASME Fluid Meters: Their Theory and Application
Practical Value
ASTM D5390-21 delivers a proven and reliable methodology for the water sector, ensuring that Palmer-Bowlus flume installations produce consistent and accurate flow data. By following this standard, professionals in engineering, environmental monitoring, and municipal operations benefit from:
- Increased accuracy in water and wastewater monitoring
- Streamlined regulatory compliance
- Enhanced data integrity for operational and design decision-making
- Reduced maintenance and improved equipment lifespan through correct installation practices
For anyone involved in open-channel flow measurement or sewer system management, adherence to ASTM D5390-21 is essential for operational excellence and reliability.