Expansion bullet for heat exchanger tube

Abstract

An expansion bullet for a heat exchanger tube includes a leading edge face, a trailing edge face, and a bullet body insertable into a tube of a heat exchanger to expand the tube. The bullet body extends from the leading edge face to the trailing edge face and has an outer profile defined by a single radius. An expansion mechanism for a tube of heat exchanger includes a bullet driving device and an expansion bullet drivable by the bullet driving device. The expansion bullet includes a leading edge face, a trailing edge face, and a bullet body insertable into a tube of a heat exchanger to expand the tube. The bullet body extends from the leading edge face to the trailing edge face and has an outer profile defined by a single radius.

1 . An expansion bullet for a heat exchanger tube comprising:
 a leading edge face;   a trailing edge face; and   a bullet body insertable into a tube of a heat exchanger to expand the tube, the bullet body extending from the leading edge face to the trailing edge face, the bullet body having an outer profile defined by a single radius.   
     
     
         2 . The expansion bullet of  claim 1 , wherein the single radius is substantially continuous and unbroken from the leading edge face to the trailing edge face. 
     
     
         3 . The expansion bullet of  claim 1 , wherein a center point of the single radius is axially offset along a length of the expansion bullet. 
     
     
         4 . The expansion bullet of  claim 3 , wherein the center point is axially offset such that a leading edge face diameter is smaller than a trailing edge face diameter. 
     
     
         5 . The expansion bullet of  claim 1 , wherein the leading edge face and/or the trailing edge face are substantially axially-oriented planar faces. 
     
     
         6 . The expansion bullet of  claim 1 , wherein a center point of the single continuous radius is radially offset from a central axis of the expansion bullet. 
     
     
         7 . The expansion bullet of  claim 6 , wherein the center point is offset such that the center point is located outside of the expansion bullet. 
     
     
         8 . The expansion bullet of  claim 1 , further comprising a coating applied to the expansion bullet. 
     
     
         9 . The expansion bullet of  claim 8 , wherein the coating is one or more of a metallic coating, a plastic coating, a nano coating, or a surface treatment to reduce friction. 
     
     
         10 . The expansion bullet of  claim 1 , further comprising a bullet opening to secure the expansion bullet to a mandrel. 
     
     
         11 . An expansion mechanism for a tube of heat exchanger comprising:
 a bullet driving device; and   an expansion bullet configured to be driven by the bullet driving device:
 a leading edge face; 
 a trailing edge face; and 
 a bullet body insertable into a tube of heat exchanger to expand the tube, the bullet body extending from the leading edge face to the trailing edge face, the bullet body having an outer profile defined by a single radius. 
   
     
     
         12 . The expansion mechanism of  claim 11 , wherein the single radius is substantially continuous and unbroken from the leading edge face to the trailing edge face. 
     
     
         13 . The expansion mechanism of  claim 11 , wherein a center point of the single continuous radius is axially offset along a length of the expansion bullet. 
     
     
         14 . The expansion mechanism of  claim 13 , wherein the center point is axially offset such that a leading edge face diameter is smaller than a trailing edge face diameter. 
     
     
         15 . The expansion mechanism of  claim 11 , wherein the leading edge face and/or the trailing edge face are substantially axially-oriented planar faces. 
     
     
         16 . The expansion mechanism of  claim 11 , wherein a center point of the single continuous radius is radially offset from a central axis of the expansion bullet. 
     
     
         17 . The expansion mechanism of  claim 16 , wherein the center point is offset such that the center point is located outside of the expansion bullet. 
     
     
         18 . The expansion mechanism of  claim 11 , further comprising a coating applied to the expansion bullet. 
     
     
         19 . The expansion mechanism of  claim 18 , wherein the coating is one or more of a metallic coating, a plastic coating, a nano coating, or a surface treatment to reduce friction. 
     
     
         20 . The expansion mechanism of  claim 11 , wherein the bullet driving device is a mandrel to which the bullet is secured.