Abstract: A conduit for conveying hydrogen under conditions of high temperature and high pressure comprises a clad, seamless tubing having a substrate layer formed of a tough base material that includes iron, chromium, or nickel, or alloys thereof. The tubing further has a thin cladding or surface layer formed of an alloy including at least about 2-10% aluminum, combined with other materials that include at least one of iron and nickel and chromium, in an amount sufficient to make the surface layer capable of resisting hydrogen permeation. The conduit is formed by draw bonding a cladding tube in the substrate tube.