Patent ID: 7155952

Claim:
A method of making multiple bends to a work piece, wherein the work piece is generally tubular in configuration, the work piece comprising a first end and a second end, a first end cap substantially closing the first end and a second end cap substantially closing the second end, an internal cavity being defined within the work piece between the first end cap and the second end cap, the method comprising: introducing a fluid into said internal cavity through one of said first and second end caps; pressurizing the fluid to a first pressure within said internal cavity; conducting a first bending operation; after conducting the first bending operation but before conducting a second bending operation, adjusting the fluid to a second pressure within said internal cavity, said second pressure corresponding to a desired pressure for conducting the second bending operation; and after conducting the second bending operation but before conducting a third bending operation, adjusting the fluid to a third pressure within said internal cavity, said third pressure corresponding to a desired pressure for conducting the third bending operation.