| 摘要 |
PURPOSE:To make it possible to obtain relatively readily a steel pipe that can exhibit a corrosion preventive effect positively, by winding spirally a heat- shrinkable tape around the outer surface of a heated steel pipe that is being rotated. CONSTITUTION:A steel pipe 2 is rotated at a definite position by under rolls 1, and while a truck 32 is self-propelled concurrently with the rotational speed of the steel pipe 2 from one end of the steel pipe 2 to the other end, the outer surface of the rotated steel pipe 2 is successively heated by a heater 3 enough to the heat shrinking temperature of a heat-shrinkable tape. The heat-shrinkable tape 6 is successively fed from a tape feeder 4 onto the heated steel pipe 2 that is being rotated with a certain tension given to the tape so that the heat-shrinkable tape 6 is wound spirally around the outer surface of the pipe 2 with the opposite peripheries of the tape 6 overlapped. Thus the outer surface of the steel pipe can be covered cohesively with the heat-shrinkable tape 6 without enclosing air between them and therefore the steel pipe can be prevented effectively from being attacked by corrosion. |
