APPARATUS CONTAINING MULTIPLE SEQUENTIALLY USED INFRARED HEATING ZONES FOR TUBULAR ARTICLES

摘要

The invention is directed to an apparatus for heating an elongate tubular article, comprising a frame member adapted to be disposed around said article, a heater with multiple heating zones and a controller for operating the heating device. The apparatus may be used to apply a heat shrinkable sleeve around a welded pipe joint. The heater may be infrared and also may use thin stamped sheets. If a heat shrinkable sleeve is used, the controller may activate the heating zones from the centre of the weld outward to eliminate pockets of air. The diameter of the interior of the frame may change along the length of the frame.