Originally Posted by zombeer
Thanks guys. This probably saved me some frustration.
I was able to get a recirc going with just some water to practice. It's tricky getting these pumps primed. I'm hoping it will be easier with the head pressure of a full keggle...
I was a bit surprised at the flow rate I was getting on the return. I can't really guess how much, but it was just lower then I expected... Didn't seem much faster then if I were to just drain with gravity. Does anyone have any flow rates of this setup; keggle to pump to cfc to keggle? I'm guessing the cfc itself is pretty constrictive....
Yes, the small diameter copper tubing used for the Tubing-in-Hose CFC's is very restrictive and the substantial length adds a lot of resistance. I did a rough measurement recently and the flow was only about 1-1/2 gpm or so and maybe less than that. This is the reason that I built a chiller using 1/2" ID rigid copper. Much, much better flow rate and much faster chilling.
These pumps can be difficult to prime. A bleeder valve helps. It also helps to keep the hose on the suction side as short as possible. The additional positive pressure head of a full kettle will make it easier to prime. Large diameter hoses (1/2" ID min.) help and keep them as short as practical. Beware of restrictions caused by QD's and barbed fittings.
It's not always received well when one discovers that he needs to replace all hoses and fittings (more than once in my case) because the hose diameter is too small and restrictive. Ask me how I know that!