Reliance Industries Ltd, Jamnagar, were facing trouble with opening of casing bolt of Siemens Compressor STC-SH series. They were in possession of OEM supplied Bolt Tensioner unit, but the existing unit was unable to deliver desired force to reopen the casing bolt as it had max capacity of 250 ton @ 1800 bar. Increasing hydraulic area of the tool was also a matter of concern as available space for tool fitment was less than 150 mm. Matter became more challenging as the existing stud has yield strength of 655 Mpa with max load sustaining capacity of 266 ton. Upon thorough study of the complete technical parameter our team came to that conclusion that applied load on per bolt should be somewhere between 250 - 255 ton or 90% of the bolt yield, real challenge happens to be designing of such a tool which should accommodate within the provided space with sufficient hydraulic area to achieve at least 260 ton. Our team of engineers undertook the herculean task of designing such an equipment which should be less than 150 mm of major dia with pulling force of more than 260 ton with max capacity of up to 300 ton so as to avoid application at it's optimum design pressure. We concluded a design which was two stage single piece unit with extended length bridge body integrated with twin interconnected load cell using Auto CAD/ Fusion 360 software with ---- od and max pulling force of ----- kN @ 2400 bar where we have to restrict the pressure at 1895 bar beyond which there would be chances of bolt fracture. Manufacturing of one prototype unit undertaken post inspection of material as per ISO norms using our state of arts equipment i.e EDM, VMC, CNC and CMM machine but the next challenge was to find seal kit unit which can sustain 2400 bar pressure. Our sister concern ANK seals came up with the solution of specially designed corrugated profile duel seals with high grade of 60D PU material. Finished goods dispatched to site up on 20 Mar 18 and successfully commissioned.