Trap means for center pivot irrigation system

Claim 1

In a center pivot irrigation system comprising a pipeline extending radially from a center pivot point to distribute water from a water source at the center pivot point to spray nozzles spaced along the length of the pipeline and further comprising a plurality of mobile tower assemblies for supportably transporting the pipeline about the center pivot point, each of the towers establishing and following a corresponding fixed path about the center pivot point, the improvement comprising: substantially downwardly extending pipe means coupled to the pipeline immediately adjacent the tower assembly which is outermost from the center pivot point, the pipe means being transported along a path which is substantially coincident with the path followed by the outermost tower assembly, the pipe means being adapted to collect particulate matter washed along in the pipeline to the pipe means by the water and selectively release the water from the pipeline to flush the particulate matter from the pipeline through the pipe means; removable cap means mounted to the end of the substantially downwardly extending pipe means to close off the bottom end of the pipe means; said cap means including an end wall having an aperture therein and further including removable plug means mounted in the cap means to close the aperture, the aperture being dimensioned to restrict the rate at which water is released through the substantially downwardly extending pipe means.