If you are still trying to "fix" this without cutting the pipe, in your first picture, you have the piece that was screwed to the threaded portion of the pipe in the ground. Take that to a local sprinkler/irrigation company and see they have a cap of some sort that will screw onto that coupling.
If you want/need to cobble something up that will work for a short time, you could fabricate a steel disc that would just fit inside that piece and a rubber disc or rubber washer that also fits inside that piece.
But the right fix is to cut and cap the existing pipe.
If you want/need to cobble something up that will work for a short time, you could fabricate a steel disc that would just fit inside that piece and a rubber disc or rubber washer that also fits inside that piece.
But the right fix is to cut and cap the existing pipe.
