Limited permeability sheath and application to pressure pipes

摘要

The present invention relates to flexible pipes with metal armors and metal tubes having a sheath made of an extrudable thermoplastic material for manufacturing an acid gas tight barrier. The sheath comprises a determined proportion of at least one charge of a product chemically active with acid gases so as to irreversibly annihilate the corrosive effects of these gases, the proportion being determined as a function of the gas permeability of the thermoplastic material.