Just got a chugger pump, I have 3/8 ball valves on my Keggles am I going to get enough flow to the pump,I don't want to damage it,should I move up to 1/2 inch ball valves?
I would (and did - well, always had 1/2" full port valves). But if you have a ball valve on the output side of the pump, you probably could restrict the output enough that the pump won't cavitate because of the 3/8" upstream fittings...
The fittings feeding the pump should be 1/2. You don't want to restrict the inlet or the pump may cavitate. 3/8 on the output will work but your flow will definitely be reduced.