spirovents

Brad White

for the simple reason that the pressure at the suction side is lower than on the discharge side.

(Technically the suction pressure is the same as when the pump is not running if that is where the expansion tank is connected, another issue. Point is, it is the lowest pressure in the system at that level.)

It is at this lowest pressure that the air bubbles are largest or at least consistently so, hence easier to catch. :)

In the big picture, the Spirovents are piped at the suction side because it's a handy place to connect an expansion tank, what you really want to do.

All things considered, if the low pressure big bubble theory holds, the best place would be at the top of the system on a common return line. But who would remember it was there?

drew w ,little rhody

spirovents

Im new to heating,just read pumping away, the company I work for always uses spirovents. I was wondering if it is still as important to have circ on feed pumping away from spiro or will it work just as well on the return?