a tube with a tube wall composed of flexible material webs for covering pipe lines and for producing pipes and a unit for producing same . the tube wall is composed as a tube of two outer webs with longitudinal edges fused with one another and consisting of at least one tubular tension web made of glass fiber webs and mats lying in the interior of the outer covering . the longitudinal edges of the tension web are superimposed loosely to an overlapping , and the tension web is resin impregnated . the unit includes guide rollers , a core freely mounted on the guide rollers and made of core segments coupled with one another and having a width and an axis , clamping shafts projecting over the width of the core , reels mounted on the clamping shafts including material webs in a plurality of stations over and under the core , wherein the reels are offset with respect to the axis of the core and wherein the core extends through the plurality of stations and wherein the webs are guided around the guide rollers onto the core , and a cylinder downstream of the core being coupled to a front end of the core .