To refurbish the assembly, FAB 3R faced a series of tricky tasks: disassembling it, removing deposits from wear and debris, adding new materials, ensuring stress release, machining the shaft and sleeve, carrying out various tests (including a methylene blue test) and finally reassembling it.

But before all that? We first had to successfully bring the assembly to the pit where it could be taken apart. To do this, enough space had to be freed up for the crane carrying the assembly, and it had to get through without disrupting other projects underway. Talk about logistics! 

To be reconditioned, the parts first had to be taken apart. Given the height required to remove the sleeve and shaft (a minimum of the combined height of the two), FAB 3R didn’t have a choice: the assembly had to be placed vertically in a pit. The team also had to make sure the parts would be stable enough throughout the disassembly to support the 500 tonnes of pressure exerted by the hydraulic cylinder! Our specialist did some out-of-the-box thinking to set all the required tooling to secure the parts.

Machining the sleeve was also an unusual challenge. Given its cone shape, it wasn’t a possibility to use a traditional steady rest, which wouldn’t have provided uniform support. Instead, we had to design customized tooling that would stabilize it according to the axes of the machine and keep it perfectly balanced during the machining.

Just the disassembly and reassembly required strength and the appropriate facilities, but to conduct the methylene blue test, FAB 3R also had to show off a little of its fancy footing. We had to delicately insert the pieces one into the next, aligning them with surgery-like precision in their final positions. Any rubbing would have falsified the test results!