Installing a Parshall flume involves several steps, including site preparation, flume positioning, and securing it in place. The process requires precision to ensure accurate flow measurement. Here’s a step-by-step guide:
1. Site Preparation
- Survey the Area: Identify the best location for the flume. Choose a straight section of the channel with a consistent flow and minimal turbulence.
- Excavate the Site: Prepare a trench or area where the flume will be installed. The trench should accommodate the flume’s size and shape, leaving room for anchoring and adjustments.
- Level the Base: Ensure the base is level and stable. A level base is crucial for accurate flow measurement. Use concrete or compacted soil as needed.
2. Prepare the Flume
- Inspect the Flume: Check for damage or irregularities that might affect its installation or operation.
- Seal the Joints: If the flume is made of multiple sections, assemble and seal the joints with waterproof materials like silicone or epoxy.
3. Position the Flume
- Align with the Flow: Place the flume in the channel, ensuring it is centered and aligned with the direction of flow.
- Set the Invert Elevation: Ensure the flume’s throat (the narrowest part) is at the correct elevation relative to the flow line. Use a level or laser leveling tool for accuracy.
- Check for Levelness: Ensure the flume is level from side to side and properly sloped in the direction of flow as specified by the manufacturer.
5. Install Accessories
- Flow Measurement Devices: Attach any required flow meters, staff gauges, or ultrasonic sensors according to manufacturer guidelines.
- Connect Upstream and Downstream Channels: Ensure smooth transitions at the inlet and outlet to minimize turbulence and ensure accurate measurements.
6. Test the Installation
- Inspect for Leaks: Run water through the flume to check for leaks or misalignments.
- Verify Measurements: Compare flow readings with expected values to confirm accuracy.
- Adjust if Necessary: Make any necessary adjustments to the alignment, level, or sealing.
7. Maintenance and Calibration
- Regularly inspect the flume for sediment buildup, blockages, or wear.
- Calibrate measurement devices periodically to ensure continued accuracy.
