I was bored this am, and decided to search the web and dig up P-Q curves for the most common wcer pumps used/sold today. I got the curves from the following places:
Hydor L20 and L30:
http://www.cooltechnica.com/images/H...30_PQ_Data.pdf
Eheim pumps:
http://forums.procooling.com/vbb/att...=&postid=44918
Sicce Idra:
http://www.sicce.co.uk/Idragra.gif
Via Aqua 1300:
http://www.wcaquatics.com/cgi-bin/it...aqua_pump.html
A note: The Via Aqua 1300 numbers as reported in their table do NOT result in a normal P-Q curve. I suspect that the max head of the the 1300 is much closer to 5 feet than to 6, and that the numbers are not exactly correct. I'used the P-Q curve provided on that page rather than the numbers in the table. It lists max flow of 400 GPH rather than the 370 reported by other vendors.
Another note: I just read representative points off the graphs and then used them to make a crude P-Q curve of my own. They obviously may be off by a few %.
Anyway, here goes: