I remove and breakdown my ball valves after 3 or 4 batches. After brewing I use PBW and heat to 160 with recirculation through my wort pump. I then use SaniClean to sanitize before I put it away. I've never had any issues with doing this. While I run the PBW I open and close the ball valves to make sure the ball gets clean. Some people break them down after every brew. I will break them all down if I'm not going to brew for some time. I normally brew frequently, thus every 3 or 4 batches. Everything is getting boiled. I do clean any valve that is on the chilling side after every brew though.