HEATPROOF BELT TO PROTECT MAINS WELD ZONE Russian patent published in 2004 - IPC

FIELD: construction. SUBSTANCE: invention relates to construction and repair of mains and it is designed for protection of pipe external insulation coating in near- weld zone in process of welding and protection of butt weld from abnormal cooling. Proposed heatproof belt contains three tapes made of heatproof material, one main tape two additional tapes, arranged on outer surface and enclosing the pipeline. Length of each of tapes exceeds length of circumference of outer surface of insulated pipeline, being made of elastic porous material impregnated with carbamide formaldehyde resin with hardener with subsequent hardening. Tapes are provided with fastening members arranged with overlapping on outer surface of pipeline. When carrying out welding jobs, to protect outer Manufacture's insulation of pipes, additional tapes are applied to their ends to cover completely Manufacture's insulation adjacent to zone of welding. After termination of welding, both additional belts are shifted to weld and main belt is placed over two additional belts with aligning its longitudinal axis and weld and is secured on pipeline. Tapes provide reliable heat insulation of weld zone. EFFECT: improved reliability of pipeline. 5 cl, 3 dwg