How To Calibrate A First Flush Diverter For Maximum Efficiency?

Understanding First Flush Diverters

A first flush diverter is a critical component in any rainwater harvesting system that prevents the first flow of contaminated water from the roof from entering the storage tank. Its efficiency depends on accurate calibration to ensure the proper separation of clean and contaminated water. To calibrate a first flush diverter, you’ll need a pressure gauge, a screwdriver, and a bucket to collect the first flush water.

Calibrating the Diverter

Attach the pressure gauge to the outlet of the diverter and turn on the rainwater flow. Monitor the pressure gauge reading as the system starts to flow. Once the gauge reading stabilizes, the diverter has collected the first flush water, which should be discarded. To adjust the diverter, loosen the screws that hold the float arm in place and adjust the float to change the amount of water that flows through the diverter. A typical first flush ratio is between 5:1 and 10:1, meaning for every 1 gallon of clean water collected, 5-10 gallons of first flush water are discarded. Adjust the diverter to achieve the desired ratio based on your specific system’s requirements.

Testing the Diverter

After calibrating the diverter, test it by collecting the first flush water in a bucket and measuring its volume. Compare this volume to the total volume of water collected during the test. If the first flush water volume exceeds the desired ratio, adjust the diverter accordingly. It’s essential to regularly test and adjust the diverter to ensure its efficiency and maintain the integrity of the rainwater harvesting system.