I would say there is no standard age for equipment but I would say that as a rough guide 7 to 10 years. Technology moves very fast these days and although equipment may still be supported it is technologically obsolete. A typical example of this I would say is ultrasound scanners.
Yes, the Graseby 3100,3150,3200 etc is still available and will be supported for 5 years from last date of manufacture. If you consider that the Omnifuse was brought out to replace the 3000 series I think you are probably looking to only a further year or two before they cease production. Technology in infusion devices has moved on quite considerably too with faster start up times and better loading of syringes to provide safer infusions.
