Abstract: When aligning heavy shafts, their flanges (4, 5) are first roughly aligned, after which an expander bolt (10) is inserted through the roughly aligned flange holes (16). The expander bolts have a conical core (6) and internally conical sleeves (1, 2) arranged axially separated from each other thereon. First the sleeves (1, 2) are inserted into the relevant flange (4, 5) to the plane (50) between the shaft flanges. Then the bolt core (6) is inserted through the sleeves (1, 2), the front end of the conical section (64) passing the plane (20) between the sleeves (1, 2). In order to keep the nearest sleeve (1) at the plane (50) when the bolt core (6) is being drawn, a spacer (8) is used which is placed on the drawn end of the bolt shaft (6) and has a head (86) located between a drawing device (7) fitted on the bolt shaft (6) and the exposed end surface (41) of the adjacent shaft flange.

Abstract: A method and a expansion plug for removably plugging a channel (2) in an element (1), particularly a hollow turbine shaft, the expansion plug being inserted into the one end of the channel and expanded therein. For this purpose a plug is used of the kind comprising a sleeve (4) whose outer wall (5) having such dimension that the sleeve can easily be inserted into the channel. The inner wall (9) of the sleeve is slightly conical. A conical stopper (11) is arranged in the sleeve (4) in order to expand the sleeve (4) by axial displacement therein, to engagement with the channel wall. The end of the sleeve (4) with larger diameter is closed. The plug is provided with a channel (18) extending between these two ends. Oil is forced through the channel (18) to a closed space (14)between the inner end of the stopper (11) and the closed end of the sleeve (4) to cause expansion of the plug.