No matter how high quality your pipe fittings were when they were first installed, no fittings are going to last forever, and with new developments being made all the time older fittings may also simply not be as effective as much newer solutions could be.
The whole point of quality fittings is to ensure that businesses can work effectively and safely, and if the fittings that are currently in use are not up to scratch, then there will be many potential problems that can arise.
It is also worth remembering that different fittings and flanges may well be needed in different circumstances, even within the same space or same company. Whilst ordinary metal fittings may still be more than suitable for certain machinery or piping, it may be that titanium or even plastic fittings are actually going to be the best possible solution in other instances.
Plastic of course will have many limited functions and therefore even when updating fittings to more modern and safer solutions, it will be worth talking to those who specialise in the fabrication of such items to see which specific fittings will be most suitable for your own needs and your own machinery and pipes.
It is not just time that will provoke a need to reassess current fittings, but also any changes in environment or processes. Different fittings will be more or less suited to different temperatures, chemicals and even pressures and it will therefore be vital to review your needs each and every time you make any changes to the way in which you carry out your work.