DUPLEX (TWO)
Longer periods of rest can be provided by installing two siphons in the dosing tank and alternately discharging the tank into one-half of the field at a time. The american siphon is hydraulically designed to automatically alternate when two siphons are installed. This is accomplished with no moving parts as it relies upon the hydraulic design of the siphon.

When the liquid rises in the tank above the open end of the vent pipe affects an air seal. As the liquid continues to rise air trapped in the dome and the long leg of the main trap forces water out of the trap. When the head of the liquid in the tank forces all of the long leg of the trap a quantity of air will be forced around the lower bend. Liquid in the short leg of the trap will be rapidly forced out of the short leg by the up rush of air and will start the siphon action. The liquid is drawn out of the tank until air reaches the bottom of the dome which stops the siphon action.

SIMPLEX SIPHON CYCLE COUNTER