The extra cleaning is for peace of mind. I sometimes go months without brewing. I will definitely be more diligent with my ball valves in the future.

It's been a while since the last post on this thread, but I just noticed this on Brulosophy;

Seems it is still happening out there to some of us?

I found some gunk in my tap a while back. Normally I am quite diligent, but we all have lapses in memory and streaks of laziness.

Great find mally, and a lesson for all.

---Todd

Previous posts on cleaning the kettle's ball valve saved my behind. I avoided embarrassment because I thoroughly cleaned the darn thing after reading those and found a threatening color in the deal. It would have been a major failure for me after my line of work involving GMP (Good Manufacturing Practice) and CBT (Clean By Test) procedures where it's not clean unless you clean it, and it's not proven clean until you prove it. I much prefer non-GMP work where one can get away with "Don't look, I'm going to run this reaction solution down a pad column of silica gel." So thanks for the earlier posts on ball valves and if those new to the forum missed them, this one is good, too.
I have a thin stainless steel plate that goes between the burner and the kettle bottom under the valve, presumably to keep the valve and its gaskets from getting too hot - I read that as keeping it from getting sanitised by the heat of the flame.