There are a number of variables effecting the usable flow from a jet siphon-style water transfer device. Much like the collaborative work that we did on suction strainer testing in 2017, our 2012 project on jet siphon flow testing showed wide variances in the flow produced by the devices. We were never able to quantify the various water motives needed to make the test devices perform at optimum flow. We do know however that the water flow needed to make the jet transfers work has an impact on the pumper's total output ability.

Last month in Bexar County, Texas we were able to use a TFT Sho-Flow Water Flow Meter on the 1-3/4-inch feeder line to a standard 6-inch jet siphon and the Sho-Flow recorded a flow of 140 gpm used to produce a good looking output stream on the discharge end of the 10-ft length of suction hose.

Nothing here was scientific....there were variables that were not controlled.....but, that 140 gpm needed to make the simple jet siphon work is 140 gpm that could not be pumped to the fireground. Another reason for trying to use large capacity (1500 gpm+) pumps at the dump site when running multiple water transfer devices.