Rotary impact sprinklers were introduced in the late thirties. However, it was not until after World War II, when aluminum pipe became available, that portable hand-move systems became practical. Most of the early rotary impact sprinklers were low capacity, medium pressure, and constructed of brass. Some companies supplied gun sprinklers, but early models were not very satisfactory, because of the high application rate and potential for runoff. Over the years, the trend has been toward larger sprinklers.
Sprinklers are now available with plastic, brass, aluminum, and some stainless steel components.
Improvements in bearings contribute to longer life and less maintenance. Quality control has also improved. The major change in aluminum pipe has been a trend toward thinner wall aluminum pipe and stronger alloys. Couplers and gaskets have been improved to reduce leaks at joints. The number of coupler manufacturers has been reduced.