I'm running a plate chiller so I've gotten into the habit of cleaning everything in the post-boil stream in a certain way:
- After wort is run through chiller and into fermenter, I hose out the boil kettle and run clean water both ways through the chiller.
- Fill brew pot with several gallons of PBW and pump through for several minutes.
- Leave until next brew day
- On brew day, heat several gallons of PBW and pump through chiller both ways for about 20 minutes
- Leave PBW in chiller while prepping for mash
- After dough-in/strike drain and rinse boil pot and chiller with 2-3 gallons of water and configure chiller for hookup later.
- Set up mash tun for recirc, mash as usual, collect wort and sparge (using pump).
- At 15 minutes left in boil, connect pump to boil pot and chiller plate and clear any water from the system let run for at least 10 minutes
- At flame out, hook up cooling water to chiller plate and start to recirc/chill
- Fill fermenter with chilled wort.
- Repeat
If brew day is relatively early, I'll heat PBW after I'm done for cleaning the chiller, but if it's a late one, I'll tack that part onto the beginning of the next brew day. Rinsing thoroughly is the key and running/soaking hot PBW at some point is important for keeping anything from building up. I don't worry about ball valves, though it's good to run them full open when cleaning/sanitizing. When I was just draining the boil pot and not running a chiller, I'd run a few quarts through and pour back into the boil pot during the last few minutes of boil just to be sure the fittings were clear and heated to boiling temp.