One significant problem identified as responsible for consuming large amounts of outage time was the re-alignment of coupling flanges and their bolt holes on each jack shaft connecting the turbine wheel to the generator.
ACRES conducted a review of available technologies to solve the issue and after discussions with PILGRIM decided on PILGRIM’s Radial Fit Bolt.
PILGRIM selected its Radial Fit Bolts to solve the problem. The principle of the bolt is of a taper shank bolt drawn into a matching taper sleeve with parallel outer diameter which expands fractionally to produce a perfect interference condition in to the bolt hole. This condition, which “conventional” fitted bolts do not achieve, eliminates movement between mating components. Also with the expansion of the sleeve], exact flange alignment and concentricity is achieved. Axial clamp load is then created by a hydraulic puller. Once the puller draws the tapered bolt into its sleeve it is then used to tension the bolt once the nuts are fitted.