Originally Posted by
Zac Penn
Just for fun, I disconnected the float on my ZacoDraco and cranked the FlowFriend up to 2600 RPM and the ultrasonic flow meter read 17,258 GPH. The ZacoDraco and Testing Tank are connected with two 4" pipes roughly 4' long, and a hard 90 at each end. The drawdown between the tanks was 7" under gravity flow conditions. So at 8,629 GPH each of those pipes had a 7" drawdown in order to flow that much water.
Normally this kind of plumbing configuration would be able to achieve around 4,000 GPH with only a 1.75" drawdown between the tanks, so it really goes to show you that doubling the flow rate does not mean simply doubling the drawdown. I already knew this, but I figured it would be a fun learning experience for others. I did not know what the actual drawdown would be on that setup at max flow for the pump so I gave it shot.
The pump was connected with a single 4" suction pipe about 5' long, with one hard 90 and a 4" swing check valve. The outlet was roughly 9' long with a Fernco 90, a hard 90 and a 4" ball valve.
Total head height was 2' and power consumed was 760 watts.
Not bad for a water pump and 2' of head could yield you a nice low profile shower like what Kimini built.