METHOD OF CLEANING OF PIPE SURFACE FROM POLYMER COATING Russian patent published in 1999 - IPC

FIELD: construction and repairs of main gas and oil pipelines; applicable in any industry where there is need for cleaning of surfaces of new and old pipes, bodies of revolution and also other articles from insulation and other coatings bound to article surface with the help of adhesive mastics (primers). SUBSTANCE: method includes heating of coating and mechanical cleaning of surface by acting on coating with blade tool with subsequent removal of coating. In so doing, coating is heated in zone of contact with tool to temperature of 67-115 C with the help of hot air and other heat carriers. Cleaning is continued, first, by electric arc discharges at atmospheric pressure in medium of protective, reducing or protective-reducing gas, and then, in vacuum under conditions of increasing section of volt-ampere characteristic with use of graphite anode and treated article as cathode. In this case, electric arc discharges are moved over surface of cleaned article mechanically and/or by magnetic fields. EFFECT: higher quality of cleaning and extended process potentialities due to qualitative cleaning of oil sucker rods and tubings, and old pipes.