The present invention relates to a multilayer tubular structure (MLT) intended for the transport of a heat transfer fluid, said multilayer tubular structure comprising: at least one layer (1) comprising a composition (1) mainly comprising at least one long-lasting polyamide chain having 10 to 15 carbon atoms per nitrogen atom and comprising at least 50% of aliphatic units relative to the sum of the units present in said long-chain polyamide, at least one layer (2) situated below said layer (1) comprising a composition (2) mainly comprising at least one polyamide having from 4 to 9 carbon atoms per nitrogen atom, said polyamide comprising at least 50% of aliphatic units relative to the sum of the units present in said polyamide, said composition (2) comprising up to 12% of polyolefins, in particular up to 6% by weight of polyolefin, relative to the total weight of said composition (2), and up to 2% by weight of at least one plasticizer relative to the total weight of said composition (2), optionally a layer (3) comprising a composition (3) as defined for the composition (1) or comprising a composition (3 ') comprising mainly a short chain polyamide having from 4 to 7 carbon atoms per nitrogen atom and at least 20%, preferably at least 25% by weight of at least one polyolefin relative to the total weight of said composition (3 ') , or a composition (4) comprising a polyamide comprising at least 50% of semi-aromatic units, said layer (1) being devoid of continuous fibers, said layer (2) being in contact with said transported fluid when said layer (3) is is not present, and said layer (s) (2) representing at least 50% of the total thickness of the tube.
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