hello newc, we have been performing bolting services in refinery and petrochemical plants for many years, some have been on Superbolt. I have come across this problem on occasion with superbolt. The superbolt is like a minature flange with 8,12 or 16 jackscrews that all have to be torqued. While the torque is fairly low, the stresses in the jackscrews are VERY high. While the nuts are designed for these high stresses, what can happen is they can increase further and seize during disassembly particularly if the operator undoes them quickly without following a precise pattern.
In a bolted joint with many superbolts, you have to follow a torque pattern for each superbolt and a torque pattern for the whole flange, tightening in stages until it is complete. There can many hundreds of "touches" for each flange taking much longer than desired.
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