PURPOSE: To help eliminate scales etc. within fluid pipeline, by placing a permanent magnet of specific form on its way so as to get astride said pipeline with the lower inner ridges of plate-form yokes attached to the both ends of said magnet coming into contact with the outer diameter lines of said pipeline facing each other.

CONSTITUTION: A permanent magnet of specific form 10 is placed on the way of pipeline P for fluid such as heavy oil so as to get astride said pipeline with the lower inner ridges 27, 27 of plate-form yokes 20, 20 attached to the both ends 11, 12 coming into contact with the outer diameter lines d1m d2 of said pipeline facing each other, thus helping eliminate scales and/or sludges present within the pipeline, leading to significant decrease in the work for removing such impurities.