Production-optimized process for producing a multilayer pipe

Abstract

A process for producing a multilayer pipe ( 5 ) with the aid of a plate forming machine, in which individual layers of material ( 1, 2 ) to be combined to form the multilayer pipe ( 5 ) are laid one on top of the other, at least one of the layers of material ( 1 ) consisting of more than one laid-on element ( 1 a, 1 b ), after that, a first connection ( 3 a, 3 b ), respectively, is then created between the bordering elements of the overlying layer of material ( 1 a, 1 b ) and the adjacent layer of material ( 2 ), the multilayer material formed in this way is formed into the pipe ( 5 ) and, during the deformation, the edges ( 4 a, 4 b ) of the elements ( 1 a, 1 b ) of the overlying layer of material ( 1 a, 1 b ) that are still freely displaceable with respect to one another can move freely toward one another in accordance with the extent to which deforming has progressed, on account of the different circumferential lengths of the inner pipe ( 1 a, 1 b ) and the outer pipe ( 2 ), then, after deforming has progressed to a certain extent, these edges ( 4 a, 4 b ) of the elements ( 1 a, 1 b ) of the overlying layer of material ( 1 a, 1 b ) that are moving toward one another butt against one another, and then the multilayer pipe ( 5 ) is formed to completion with the aid of the plate forming machine, the edges ( 4 a, 4 b ) of the elements ( 1 a, 1 b ) of the overlying layer of material ( 1 a, 1 b ) then no longer being able to move freely toward one another during this final forming, as a result of which the layer of material ( 1 a, 1 b ) respectively acting as the inner pipe is pressed with a force fit into the layer of material ( 2 ) respectively acting as the outer pipe.

1 - 15 . (canceled) 
     
     
         16 . A process for producing a multilayer pipe ( 5 ) with the aid of a plate forming machine, characterized in that
 individual layers of material ( 1 ,  2 ) to be combined to form the multilayer pipe ( 5 ) are laid one on top of the other, at least one of the layers of material ( 1 ) consisting of more than one laid-on element ( 1   a,    1   b ),   after that, a first connection ( 3   a,    3   b ), respectively, is then created between the elements of the overlying layer of material ( 1   a,    1   b ) and the adjacent layer of material ( 2 ) on the border along one of the longitudinal or transverse edges of the respective element of the overlying layer of material ( 1 ,  1   a,    1   b ), or approximately along a line parallel thereto, but always along or parallel to the future longitudinal seam ( 8 ) of the pipe,   the multilayer material formed in this way is formed into the pipe ( 5 ) and, during the deformation, the edges ( 4   a,    4   b ) of the elements ( 1   a,    1   b ) of the overlying layer of material ( 1   a,    1   b ) that are still freely displaceable with respect to one another can move freely toward one another in accordance with the extent to which deforming has progressed, on account of the different circumferential lengths of the inner pipe ( 1   a,    1   b ) and the outer pipe ( 2 ),   
       characterized in that
 then, after deforming has progressed to a certain extent, these edges ( 4   a,    4   b ) of the elements ( 1   a,    1   b ) of the overlying layer of material ( 1   a,    1   b ) that are moving toward one another butt against one another, and 
 then the multilayer pipe ( 5 ) is formed to completion with the aid of the plate forming machine, the edges ( 4   a,    4   b ) of the elements ( 1   a,    1   b ) of the overlying layer of material ( 1   a,    1   b ) then no longer being able to move freely toward one another during this final forming, as a result of which the layer of material ( 1   a,    1   b ) respectively acting as the inner pipe is pressed with a force fit into the layer of material ( 2 ) respectively acting as the outer pipe. 
 
     
     
         17 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that the forming of the multilayer material into the pipe is designed in such a way that, when deforming has progressed to the extent that the edges ( 4   a,    4   b ) of the elements ( 1   a,    1   b ) of the overlying layer of material ( 1   a,    1   b ) that were previously moving toward one another butt against one another, the pipe to be formed has already been made to curve at every point at which the inner layer and the outer layer lie one on top of the other. 
     
     
         18 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that, in the finished multilayer pipe ( 5 ), the layer of material ( 1 ,  1   a,    1   b ) acting as the inner pipe forms a pitch circle in cross section. 
     
     
         19 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that the layer of material ( 1 ,  1   a,    1   b ) acting as the inner pipe and forming a pitch circle in cross section of the finished multilayer pipe ( 5 ) forms a channel at the foot of the multilayer pipe. 
     
     
         20 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that a connection, preferably welding, takes place between the edges ( 4   a,    4   b ) of the elements of the overlying layer of material ( 1   a,    1   b ) that butt against one another. 
     
     
         21 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that the multilayer pipe ( 5 ) is closed by a welding ( 7 ) of the outer pipe ( 2 ) along the pipe seam ( 8 ) and a build-up welding ( 9 ) of the inner pipe ( 1 ,  1   a,    1   b ). 
     
     
         22 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that the layers of material ( 1 ,  1   a,    1   b,    2 ) are connected at the end faces of the pipe ( 5 ). 
     
     
         23 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that a double-layer pipe is produced as the multilayer pipe ( 5 ). 
     
     
         24 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that plates, preferably metal plates and particularly preferably steel plates, are used as the layer of material ( 1 ,  2 ) or elements ( 1   a,    1   b ) of the layer of material ( 1 ). 
     
     
         25 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that at least one of the connections ( 3   a,    3   b,    4   a,    4   b ) of the layers of material ( 1 ,  2 ) is performed as welding. 
     
     
         26 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that the process is designed as a continuous process in which the layers of material ( 1 ,  1   a,    1   b,    2 ) to be combined or elements ( 1   a,    1   b ) thereof are respectively unwound from a wound-up strip and then continuously laid one on top of the other and continuously connected, preferably welded, the subsequent pipe forming process likewise taking place continuously, in that a forming line which forms an open-seam pipe ( 5 ) from the layers of material laid continuously one on top of the other serves as the plate forming machine. 
     
     
         27 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that a bending roll is used as the plate forming machine. 
     
     
         28 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that a UO(E) press / die arrangement ( 13 ,  14 ,  15 ) is used as the plate forming machine. 
     
     
         29 . The process for producing a multilayer pipe ( 5 ) as claimed in  claim 16 , characterized in that a JCO press/die arrangement is used as the plate forming machine.