Patent ID: 6899842

Claim:
A process for laying a cylindrical pipe in a trench (T) open at the top, starting from a section of flattened flexible tubular preform ( 1 , 9 ), capable of being made round but not radially expansible by inflation due to the effect of internal pressure, wherein the wall of the preform ( 1 , 9 ) includes a filamentary reinforcement ( 2 ) surrounding an inner sealing skin ( 10 ), characterized in that, on the one hand, this laying process is carried out without the wall of the preform ( 1 , 9 ) being turned over on itself, and, on the other hand, the process is carried out in the following manner: a) the section of preform ( 1 ) is brought close to the trench (T); b) the reinforcement ( 2 ) is impregnated in situ with a curable resin ( 11 ); c) the section of resin-impregnated preform ( 9 ) still in the flattened state is deposited from the top down into the trench (T); d) the section of preform ( 9 ) is inflated pneumatically, after having closed off the ends thereof, so as to give it a cylindrical shape; e) the resin ( 11 ) is made to curie by heating by electrical resistance elements ( 21 ) incorporated into the reinforcement ( 2 ); wherein operations (b) and (c) are carried out continuously.