Great diagram Broomer, thank you. I know everyone appreciates you taking the time and effort to make up such a nice drawing. It really helps when you are trying out the plumbing thing for the first time, even with simple stuff.
Scott: Yes. I plumbed the swing check valve in a vertical run of pipe. The Mc Master-Carr online catalog was really good at specifying the performance and installation details on all of the check valves they offer (ALOT!). Very, very good point.
U235: The catalog I used to choose my check valve was pretty specific on the pros and cons of using each type of valve, including flow restriction. I really dont notice any more resistance on my pump since I installed mine. But, I chose one that really wasn't supposed to interfere much anyway. There are many, many types available. You kind of have to do your research. They are definetly not all the same.
BigMac: I do have my check valve situated so that I can remove it from the line (via a pvc union and a threaded connection to my return pump). So, I can clean it when I am doing maintainence. I also wouldn't rely on it exclusively. I am just a worrier, so this helps me mentally more than anything.
Thank you all for your responses. It was just a few months ago that I was asking these same questions and I wouldn't be as far along as I am now with out you! My lfs certainly wasn't this helpful with these details, and even then it was usually the advice/ opinion of one person. Then, of course the next time I was there a different person would tell me something else...
Thank god for swf.com!
-Christine