Okay now I feel like a total noob. My setup is thus: hose from the BK to the pump, from the pump to the PC, then the PC back to the BK and eventually the fermenter. The only way I control the flow is with the valve from the BK. I always turn it down about halfway once I get the flow started so the wort moves slower through the PC. Never had an issue, and always backflush the chiller with super hot water when I'm done (and bake it in the oven every month or so to burn up anything that might be left). I can't mount my PC to the brewstand because the connectors for the water in/out leak (too lazy to fix, it sits in a bucket during chilling to catch leaking water). Now I'm thinking I might have to do that.