Before the advent of 'i - LOK' technology believe it or not the flex joints had no liners at all leaving the convoluted flex hose visible and exposed to absorb this hostile environment on it's own.
Very quickly the short comings of this solution to transverse motion were exposed at this end of the performance spectrum, in spite of the fact that the development of the flexible de coupler by Senior Flexonics had been a life saver to the automotive industry after the problematic and completely inadequate - from a warranty perspective mechanical spherical joints - (Those that remember virtually the entire British Leyland range relying on this design - and the subsequent growth in the exhaust fast industry growing in response to the need for replacement every twelve months
- will bear this out).
So the inner braid was the first solution, a design which was copied by both Indian and Chinese manufacturers supplying predominantly fluid flexible solutions not gas - sadly it fails to give the structural integrity over a long period that the 'i - LOK' gives, which in itself, inspite of what manufacturers tell you is not a totally 'bomb proof' design. The key to minimising the products failure risk (at this level) is to ensure on high performance applications that the flexible joint is sufficiently long enough to absorb both the mechanical energy and heat energy (Those of us that remember the 1st law of thermodynamics from our school days will understand this) in order to prevent the transference from causing the flex to crack or in the case of the braided inner style balooning as described in my earlier post.
As JMP says though this part can be replaced and a superior unit welded back into position as both the inlet and out let straight sections appear long enough to take a longer version - it would just be nicer for the owner not to have to undertake the hassle of this if it occurs
Cheers
Nige