Expanding bolts with induction is the proven time and labour-saving alternative to inefficient flame and resistance heating. With induction, a specially designed coil is inserted into the bolt. Rapid, precisely controlled and localized heat is then induced.
Induction bolt heating system is a cart-mounted portable induction power supply designed to generate rapid heating of bolts for field assembly and disassembly of the steam turbine horizontal joint. Power is generated and transmitted to the stud hole, via long leads connected to a small diameter induction coil that is inserted into the bolt. Thermal elongation in bolts up to 6-inches in diameter occurs in minutes, enabling workers to loosen large fasteners quickly, thereby reducing the overall time necessary for completion of critical path outages. This process also reduces safety concerns with the forceful removal of nuts with sledgehammers and flogging spanners. Seized nuts can more easily be removed using nut coiling system, without further damage to stud or nut. It has been proven to significantly reduce outages, occasionally by days, which results in huge savings to the plant owner.