Method for hydraulically expanding tubular members

Abstract

System and method for hydraulically expanding tubular members, such as heat transfer tubes and sleeves of the type found in nuclear steam generators. The system includes a resilient ribbed bladder for radially expanding the tube or tubular sleeve that is to be disposed in the tube. The system further includes a pressurizer hydraulically connected to the bladder for supplying pressurized hydraulic fluid to the bladder in order to expand the bladder into intimate engagement with the sleeve and/or tube. The system also includes a controller electrically connected to the pressurizer for controllably operating the pressurizer. The system may further include a fluid supply reservoir fluidly connected to the pressurizer for supplying fluid to the pressurizer and may also include visual display means electrically connected to the controller for displaying the pressure acting on the bladder during the expansion process. The ribbed structure of the bladder allows the bladder to radially expand over a larger diameter without rupture of the bladder and also allows the bladder to expand relatively short axial sections of the tube and/or sleeve.