Expiring Patches on Package Server

Hello, I am very new to Altiris and getting my feet wet but had a question on expiring patches, to see if this can be done.

So let's say you approve patches and they are distributed out to the package server at the intended sites and everything works successfully.  After say 4 months, if the filter does not pick up any workstation/servers that need a certain patch, can it be expired and content deleted at that site package server, but then if a machine that doesn't have the patch gets turned on, can it pull it from the main site, without having to push it back out the the site it's on?

I hope this isn't clear as mud and I appreaciate any help and insight.