Hello Scott,
I don't have much using experience of System, but if it's working for most components, except for valves, then maybe I can help you with figuring out what is different for valves. When the check-in fails, is there some specific error messages which could provide us with more details? Does all valves fail, or maybe just some, for example control valves? Do you use SYSTEM for tagging in valves or other components?
Looking forward for more details,
Justinas