I have an"old" canner that I still use. Every year before I use it I take the top to the County Extension office where they have a machine to test the seal and valve for safety. My mother used it before me so for 50+ years it's still working and was a great buy!
So sorry I missed your comment earlier! Pressure canners are certainly built to last! I "inherited" two, from both of my grandmothers, and they are definitely solidly built! The pressure gauges were becoming increasingly unreliable, however, and the local extension service no longer offered testing, so I finally broke down and purchased a new one. I decided to splurge on one that could handle a double-layer of pint jars, and have never regretted the purchase!
I still have both of the older canners, however, and like to pull them out for things that only need a water bath. The memories associated with them are so sweet, I can't bring myself to think of parting with them, regardless of how much space it takes to store two old and one new one!