You can expect our product to outlast your engine, a lot of our customers have had their Fumoto valves for 20+ years!
As for the gaskets or o-ring, you don't need to replace them in most cases. However, if you remove the valve and install it again into the oil pan, please replace the gasket or o-ring. In case oil leaks from the gasket, you may need to replace the gasket or o-ring to fix the issue.
You can always purchase a few extra gaskets, just in case.