I'm asking because I don't know how to figure it out. How much pressure would be in a siphon system that had open intake and open discharge? Water IS moving thru the system, but it's not like pumps are pushing it. I'd think you would have to worry more about it collapsing than bursting?

www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).