Apparatus with strake elements and methods for installing strake elements

Abstract

There is disclosed an apparatus comprising a plurality of strake elements, each strake element adapted to cover an arc-angle about a circumference of a structural element; and a mechanism adapted to attach the strake elements to each other to cover at least a portion of the circumference of the structural element.

1 . An apparatus, comprising: 
 a plurality of strake elements, each strake element adapted to cover an arc-angle about a circumference of a structural element; and    a mechanism adapted to attach the strake elements to each other to cover at least a portion of the circumference of the structural element.    
   
   
       2 . The apparatus of  claim 1 , wherein the structural element comprises a structure selected from the group consisting of a tubular, a pipe, a rod, a buoyancy device, a riser, and a mooring line.  
   
   
       3 . The apparatus of  claim 1 , wherein the mechanism for attaching comprises a plurality of bolts and nuts.  
   
   
       4 . The apparatus of  claim 1 , wherein the mechanism for attaching the strake elements comprises a plurality of heat welds.  
   
   
       5 . The apparatus of  claim 1 , comprising 4 helical strake elements, each strake element comprising an arc-angle from 70° to 120°.  
   
   
       6 . The apparatus of  claim 1 , wherein each strake element overlaps the next strake element, to form a plurality of strake shapes about the circumference of the cylindrical element, the strake shapes selected from the group consisting of triangles, rectangles, and trapezoids.  
   
   
       7 . The apparatus of  claim 1 , wherein the cylindrical element comprises an outside diameter from 5 to 60 cm, wherein the strake elements have a height from 5% to 50% of an outside diameter of the structural element, and wherein the strake elements are helical.  
   
   
       8 . The apparatus of  claim 1 , further comprising the structural element about which the plurality of strake elements has been attached.  
   
   
       9 . The apparatus of  claim 1 , comprising from 2 to 8 strake elements.  
   
   
       10 . The apparatus of  claim 1 , comprising a pitch between each strake element from 0.1 to 10 meters.  
   
   
       11 . A method of installing strake elements comprising: 
 providing a plurality of strake elements, each comprising an arc angle from 30° to 180°; and    connecting each strake element to at least one other strake element about a circumference of a structural element.    
   
   
       12 . The method of  claim 11 , wherein at least one of the strake elements has been produced by extruding the element through a die.  
   
   
       13 . The method of  claim 11 , wherein at least one of the strake elements has been produced by forming the element in a mold.  
   
   
       14 . The method of  claim 11 , wherein at least one of the strake elements has been produced by placing a moldable sheet on a strake shape, forming the moldable sheet about the desired strake shape, and removing the moldable sheet from the shape.  
   
   
       15 . The method of  claim 14 , further comprising applying suction through the strake shape, to force the moldable sheet about the desired shape.  
   
   
       16 . The method of  claim 11 , wherein connecting each strake element to at least one other strake element comprises bolting the elements to each other.  
   
   
       17 . The method of  claim 11 , wherein connecting each strake element to at least one other strake element comprises welding the elements to each other.  
   
   
       18 . The method of  claim 11 , wherein connecting each strake element to at least one other strake element comprises overlapping adjacent elements to form a desired strake shape.  
   
   
       19 . The method of  claim 11 , wherein the structural element comprises a structure selected from the group consisting of a tubular, a pipe, a rod, a buoyancy device, a riser, and a mooring line.