Abstract: Conveyor apparatus for checking the interior of a pipeline. The apparatus includes two chassis sections, one of which is adapted to drive the apparatus, and the other of which is driven. A pair of endless belts connects both of the chassis sections and are maintained in contact with the interior wall of the pipeline. The spacing between the portions of the belts in contact with the wall may be adjusted to the width of the pipeline. A swivel plate is provided to adjust the spacing between rollers which urge the belts into contact with the wall. The swivel plates and chassis sections are spring-biased to adjust the slight variations in pipeline diameter and are adjustable for different pipeline diameters.