Lawn sprinkler design starts with the water supply. Lawn sprinkler systems require roughly 3 gallons per minute per head. That is the flow the other factor is the pressure at that flow rate. Lawn sprinklers operate best between 50 to 60 PSI. The average home in Chicago land supplies around 12 GPM. So the average home in Illinois will have 4 sprinkler heads per zone.
The next thing to consider is sprinkler head placement. In wide open areas we use gear drive rotors and in tighter areas and beds we use mister heads. The spacing for gear drives is 25 ft and the mister spacing is 12 ft. With this distancing you will have head to head water coverage. This helps to have matched precipitation rate across the whole property. Also you need to consider the range of motion that the gear drives will be set at. 90 degree rotors should have a ¾ gallon nozzle. 180 degree should have 1.5 gallon nozzle. 360 degree should have 3.0 gallon nozzles. This will also help to create matched precipitation.
The final step is the placement of your valve boxes. You should never place the valve boxes in beds. Someday in the future this will make it hard to find and often by the time you need a repair in your valve box the roots from bushes will be tangled in the box making your repair much more difficult. You should also place boxes near the zones that will be in it. Finally I like to place boxes in places where there is very little traffic, like the sides of the house in the lawn. These are the basics of lawn sprinkler design to learn more about lawn sprinklers call Allscape today to learn more.