Jet siphons consume pump capacity. When trying to run a mulitple-dump tank operation using a smaller pumper (1,250 gpm or less), pump capacity given up to jet siphons can prove problematic when higher fire flows are needed. Using a brush truck or grass rig to run jet siphons can free up pump capacity for the main pumper. This only works however if the brush truck can develop sufficient pressure to make the jet siphon work right ( 125 psi or so on an 1-1/2-inch supply line to the siphon). Therefore, it is important to "try this out" with your brush truck before the "big water" event occurs.
The series of photos with this News Story are from our seminar in Franklin County, Kansas (August 2013). Cutler FD's Grass 3571 uses its 400 gpm pump to supply and operate jet siphons freeing up the 1,000 gpm draft pumper to supply the simulated fire flow.
The grass rig drafted from one dump tank and used that water to operate the jet siphons.
Not all small pumps can generate 125 psi on 1-1/2-inch hose, so it is important to give it a trial run first.
The yellow pumper (1,000 gpm) is the dump site pumper and is drafting and supplying the master stream on the red pumper. Cutler's grass rig is supporting jet siphon operations.
Cutler FD's 400 gpm grass rig was a perfect fit for supporting jet siphon operations at this water supply drill outside Ottawa, Kansas.
