BOARD FOR PROTECTING PIPELINES LAID IN ROCKS Russian patent published in 2003 - IPC

FIELD: building, namely protection of insulated surface of pipelines at laying them in rock, permafrost and in mineral grounds with inclusions of gravel, pebble, separate blocks. SUBSTANCE: board includes hollow non- closed cylinder formed by flexible web of synthetic material. Flexible web with total thickness no more than 7±0.5 mm has one or two layers of fibrous non-woven sheet material on base of fibers of polypropylene or polyether group with thickness (3.5 - 7)±0.5 mm. Fibrous non- woven material is impregnated along its whole thickness with self-setting composition on base of carbamide-formaldehyde resin at total consumption of composition no more than 7.0 ±0.5 kg/ sq.m. Such board features necessary flexibility for embracing pipeline and for further securing to it in field condition. EFFECT: enhanced reliability of pipeline due to increased shock and rubbing resistance values and due to improved stability of board against puncturing by means of sharp fractions of ground.