The traditional approach to hydrant flow tests is for you to drag Bob along with you. Bob attaches a pressure gauge on a 2.5" hydrant outlet at the point you want to measure the static/residual pressures. He then just stands there to watch the gauge.
Meanwhile at the selected flow hydrant you signal Bob to record static pressure and open the valve to the desired flow. You yell into the radio over the wind/hydrant noise to confirm the residual pressure dropped at least 25%, get your GPM flow and try to signal Bob to record the residual pressure before closing the valve.
You close the valve slow so water hammer spikes that can break water mains aren't created. No wonder that hydrant is eyeballing you when you put that regular gauge on. It knows you can't see the pressure real time and have to rely on Bob relaying if you need to slow down.
Keep Hydrants and Mains Happy While Testing
Simpler process with a Remote Pressure Set and no learning curve
You don't wait for Bob, you just go and attach a Pressure Sender with hydrant test cap to a 2.5" hydrant outlet at the static/residual pressure point and open the control valve fully. Then you head over to the flow hydrant. You will test flow same as before using your preferred methods.
You glance at the display unit hung on a neck lanyard to see the current static pressure. You long press the button to record static pressure, then double click it to advance it to the residual pressure recording spot so you're ready when its flowing.
Time to start closing the hydrant while watching the display. It's sending pressure readings 4x/sec so you'll know if pressure is spiking and to slow down way quicker than waiting for Bob to tell you.
You open the hydrant to the desired GPM and take your reading the same as you always did. Now you look down at your display to see the residual pressure and know when you got the 25% drop you want. Another long press on the button and residual pressure is saved so you don't even have to write anything down.
