Abstract: Method and apparatus for injecting foam into a pipeline. Foam is produced and delivered under pressure to the inlet of a flexible foam-conducting tube. An inflatable plug slidably encircles the tube, so that the tube can be adjusted to extend any desired distance beyond the plug. The plug can be enlarged by inflation to bear against the wall of the pipe and also against the wall of the tube, so as to prevent the foam from flowing back beyond the plug.

Abstract: A high-pressure joint tester includes a pair (or two pairs) of plugs, each plug having an annular rigid channel containing an inflatable elastomeric annular tube. The spaced, parallel plugs are joined together by a rigid cylindrical wall extending between inner sides of the channels. The tubes are inflated at preselected pressures to seal against interior pipe walls on opposite sides of a locus where two pipe ends meet at a joint, and fluid is introduced under pressure through the cylindrical wall to the outer surface thereof. Rollers support the device for movement through the pipeline to be tested.

Abstract: Method and apparatus for injecting foam into a pipeline. Foam is produced and delivered under pressure to the inlet of a flexible foam-conducting tube. An inflatable plug slidably encircles the tube, so that the tube can be adjusted to extend any desired distance beyond the plug. The plug can be enlarged by inflation to bear against the wall of the pipe and also against the wall of the tube, so as to prevent the foam from flowing back beyond the plug.