Multilayer tube consisting of, in its radial direction from the outside inwards: - a layer comprising by weight, the total being 100%:. 50 to 100% of at least one polyamide A1 of formula X, Y/Z or 6,Y2/Z, in which: - X denotes residues of an aliphatic diamine having from 6 to 10 carbon atoms, - Y denotes residues of an aliphatic dicarboxylic acid having from 10 to 14 carbon atoms, - Y2 denotes residues of an aliphatic dicarboxylic acid having from 15 to 20 carbon atoms, - Z denotes at least one unit chosen from residues of a lactam, residues of an α,Ω-aminocarboxylic acid, the unit X1, Y1, in which X1 denotes residues of a diamine and Y1 denotes residues of a diacid, - the weight ratios Z/(X+Y+Z) and Z/(6+Y2+Z) being between 0 and 15%, advantageously between 0 and 10%, and. 0 to 50% of nylon-11 or nylon-12 polyamide, and - a layer made of nylon-11 or nylon-12 polyamide, the layers being successive and adhering to one another, the layer being the layer intended to be in contact with the fluid transported. - a layer comprising by weight, the total being 100%:. 50 to 100% of at least one polyamide A1 of formula X, Y/Z or 6,Y2/Z, in which: - X denotes residues of an aliphatic diamine having from 6 to 10 carbon atoms, - Y denotes residues of an aliphatic dicarboxylic acid having from 10 to 14 carbon atoms, - Y2 denotes residues of an aliphatic dicarboxylic acid having from 15 to 20 carbon atoms, - Z denotes at least one unit chosen from residues of a lactam, residues of an α,Ω-aminocarboxylic acid, the unit X1, Y1, in which X1 denotes residues of a diamine and Y1 denotes residues of a diacid, - the weight ratios Z/(X+Y+Z) and Z/(6+Y2+Z) being between 0 and 15%, advantageously between 0 and 10%, and. 0 to 50% of nylon-11 or nylon-12 polyamide, and. 50 to 100% of at least one polyamide A1 of formula X, Y/Z or 6,Y2/Z, in which: - X denotes residues of an aliphatic diamine having from 6 to 10 carbon atoms, - Y denotes residues of an aliphatic dicarboxylic acid having from 10 to 14 carbon atoms, - Y2 denotes residues of an aliphatic dicarboxylic acid having from 15 to 20 carbon atoms, - Z denotes at least one unit chosen from residues of a lactam, residues of an α,Ω-aminocarboxylic acid, the unit X1, Y1, in which X1 denotes residues of a diamine and Y1 denotes residues of a diacid, - the weight ratios Z/(X+Y+Z) and Z/(6+Y2+Z) being between 0 and 15%, advantageously between 0 and 10%, and - X denotes residues of an aliphatic diamine having from 6 to 10 carbon atoms, - Y denotes residues of an aliphatic dicarboxylic acid having from 10 to 14 carbon atoms, - Y2 denotes residues of an aliphatic dicarboxylic acid having from 15 to 20 carbon atoms, - Z denotes at least one unit chosen from residues of a lactam, residues of an α,Ω-aminocarboxylic acid, the unit X1, Y1, in which X1 denotes residues of a diamine and Y1 denotes residues of a diacid, - the weight ratios Z/(X+Y+Z) and Z/(6+Y2+Z) being between 0 and 15%, advantageously between 0 and 10%, and. 0 to 50% of nylon-11 or nylon-12 polyamide, and - a layer made of nylon-11 or nylon-12 polyamide, the layers being successive and adhering to one another, the layer being the layer intended to be in contact with the fluid transported.