Pipe section for a pipe coil

Abstract

Metallic pipe section ( 10 ) for a pipe coil, made from one piece of pipe, comprising at least two pipe elbows ( 11, 12 ).

1 - 19 . (canceled)  
   
   
       20 . A metallic tube portion for a tube coil, comprising a single-piece tube, having at least two tube bends, wherein the tube is made of a DIN EN 10027 part 1 material selected from the group consisting of GX40CrNiSi25-20, GX40NiCrSiNb35-25, GX45NiCrSiNbTi35-25, GX35CrNiSiNb24-24, GX45NiCrSi35-25, GX43NiCrWSi35-25-4, GX10NiCrNb32-20, GX50CrNiSi30-30, G-NiCr28W, G-NiCrCoW, GX45NiCrSiNb45-35, GX13NiCrNb45-35, GX13NiCrNb37-25, GX55NiCrWZr33-30-04.  
   
   
       21 . The tube portion as claimed in  claim 20 , wherein the tube has opposite ends and includes individual subsections between the ends, wherein the subsections define a longitudinal axis which extends in more than one plane between the ends of the tube.  
   
   
       22 . The tube portion as claimed in  claim 20 , wherein the tube bends are each defined by a bending radius and a tube diameter at a ratio of bending radius to tube diameter of a tube bend which ratio, at least in sections, is less than 1.5.  
   
   
       23 . The tube portion as claimed in  claim 22 , wherein the ratio of bending radius to tube diameter, at least in sections, is less than 1.1.  
   
   
       24 . The tube portion as claimed in  claim 20 , wherein the tube bends are spaced by an intermediate length of less than 300 mm.  
   
   
       25 . The tube portion as claimed in  claim 24 , wherein the intermediate length between the tube bends is less than or equal to 40 mm.  
   
   
       26 . The tube portion as claimed in  claim 20 , wherein the tube has a substantially constant wall thickness.  
   
   
       27 . The tube portion as claimed in  claim 26 , wherein the wall thickness of the tube is between 6 mm and 14 mm.  
   
   
       28 . The tube portion as claimed in  claim 20 , wherein the tube has an inner surface which, at least in sections, has a roughness of less than 12 R a .  
   
   
       29 . The tube portion as claimed in  claim 28  wherein the inner surface of the tube, at least in sections, has a roughness of less than 3.2 R a .  
   
   
       30 . A tube coil for a chemical plant, comprising plural tubes; and at least one tube portion connected to one end of one of the tubes, said tube portion including a single-piece tube having at least two tube bends, wherein the tube is made of a DIN EN 10027 part 1 material selected from the group consisting of GX40CrNiSi25-20, GX40NiCrSiNb35-25, GX45NiCrSiNbTi35-25, GX35CrNiSiNb24-24, GX45NiCrSi35-25, GX43NiCrWSi35-25-4, GX10NiCrNb32-20, GX50CrNiSi30-30, G-NiCr28W, G-NiCrCoW, GX45NiCrSiNb45-35, GX13NiCrNb45-35, GX13NiCrNb37-25, GX55NiCrWZr33-30-04.  
   
   
       31 . The tube coil as claimed in  claim 30 , wherein the tube portion, at least at one of the ends, is connected to a tube or tube portions produced from a same material.  
   
   
       32 . A process for producing a tube portion, comprising the step of making the tube portion from a centrifugally cast tube.  
   
   
       33 . The process as claimed in  claim 32 , further comprising the step of shaping the centrifugally cast tube by inductive bending.  
   
   
       34 . The process as claimed in  claim 33 , further comprising the step of heat treating the centrifugally cast tube prior to the inductive bending step.  
   
   
       35 . The process as claimed in  claim 34 , further comprising the step of heat treating the centrifugally cast tube at a temperature of 800° C. to 1200° C. prior to the inductive bending step.  
   
   
       36 . A process for producing a tube coil comprising the step of making a tube portion from a centrifugally cast tube.  
   
   
       37 . The process as claimed in  claim 36 , further comprising the step of shaping the centrifugally cast tube by inductive bending.  
   
   
       38 . The process as claimed in  claim 37 , further comprising the step of heat treating the centrifugally cast tube prior to the inductive bending step.  
   
   
       39 . The process as claimed in  claim 38 , further comprising the step of heat treating the centrifugally cast tube at a temperature of 800° C. to 1200° C. prior to the inductive bending step.  
   
   
       40 . Fitting substitute for a tube coil with fittings, comprising a metallic tube portion including a single-piece tube having at least two tube bends, wherein the tube is made of a DIN EN 10027 part 1 material selected from the group consisting of GX40CrNiSi25-20, GX40NiCrSiNb35-25, gX45NiCrSiNbTi35-25, GX35CrNiSiNb24-24, GX45NiCrSi35-25, GX43NiCrWSi35-25-4, GX10NiCrNb32-20, GX50CrNiSi30-30, G-NiCr28W, G-NiCrCoW, GX45NiCrSiNb45-35, GX13NiCrNb45-35, GX13NiCrNb37-25, GX55NiCrWZr33-30-04.  
   
   
       41 . Cracker with a metallic tube portion including a single-piece tube having at least two tube bends, wherein the tube is made of a DIN EN 10027 part 1 material selected from the group consisting of GX40CrNiSi25-20, GX40NiCrSiNb35-25, GX45NiCrSiNbTi35-25, GX35CrNiSiNb24-24, GX45NiCrSi35-25, GX43NiCrWSi35-25-4, GX10NiCrNb32-20, GX50CrNiSi30-30, G-NiCr28W, G-NiCrCoW, GX45NiCrSiNb45-35, GX13NiCrNb45-35, GX13NiCrNb37-25, GX55NiCrWZr33-30-04.  
   
   
       42 . Cracker with a tube coil having plural tubes; and at least one tube portion connected to one end of one of the tubes, said tube portion including a single-piece tube having at least two tube bends, wherein the tube is made of a DIN EN 10027 part 1 material selected from the group consisting of GX40CrNiSi25-20, GX40NiCrSiNb35-25, GX45NiCrSiNbTi35-25, GX35CrNiSiNb24-24, GX45NiCrSi35-25, GX43NiCrWSi35-25-4, GX10NiCrNb32-20, GX50CrNiSi30-30, G-NiCr28W, G-NiCrCoW, GX45NiCrSiNb45-35, GX13NiCrNb45-35, GX13NiCrNb37-25, GX55NiCrWZr33-30-04.  
   
   
       43 . The tube portion as claimed inc laim  22 , wherein the ratio of bending radius to tube diameter, at least in sections, is less than or equal to 1.04.