Posted By geodean on 07/13/2008 12:16 PM ...
If there are no leaks and if the air has been purged and if an air eliminator is in place and if isolation valves have been installed, then your pumps will last longer. If you do need to change a pump, it will not be a big problem.
I agree.
For my water-only closed loop, I have air eliminators in place (Spirotop) at the highest points of the loop, and isolation valves around my Grundfos pumps.
I additionally have a 'make-up' system that resets once each day the loop's static pressure to about 60 psi (city's water pressure).
Best regards,
Bill