Peach Bottom had experience of conventional coupling bolts, which took hours or even days to remove and re-fit so when they heard that their sister power plant at Limerick had completed an outage in record time of only 22 days using PILGRIM’s Radial Fit Coupling Bolts and Coupling Hole Alignment Tool (CHAT), it was natural for Peach Bottom to explore the advantages of PILGRIM’s bolting technology, which can be fitted and removed in an average of 15 minutes and removes the of risk of seized bolts.
The Radial Fit Bolt features the combination of a taper bodied bolt and a matching sleeve. The sleeve is parallel outside diameter with a tapered inner diameter to match the bolt. The two are assembled into the coupling hole together in a clearance condition. Using designed hydraulic equipment, the bolts is pulled through the sleeve which is positioned and held in the bore. During this operation the sleeve expands slightly, with sufficient radial force to accurately align the flanges and provide a true interference fit. Axial load in the bolts is induced through hydraulic tensioning of the bolts to accurately achieve clamp loads.