No rocket science here. There are number of appliances that can be used to make a "rural hitch" operation work. The clappered ones tend to work best as no human is needed to open a control valve. At our seminar last month in Iowa, a 5" Storz x 2-1/2" NH 3-way clappered siamese was used to support the rural hitch operation that supplied water to an attack engine 650 feet away. The device worked just fine for the 500 gpm flow that was being sustained.