circ pump location

[fsteyer]

Hallo -

I'm doing a job where the circ pumps on a hydronic system are located on the return manifold "pulling" water through the loop rather than "pushing" on the heating supply manifold. I just have never seen it done that way and am curious if that an accepted practice.
Thanks

[hj]

I am not sure how common it is now, but in the 50's and 60's it was almost always done that way.

[Bob NH]

In a closed pressurized system the concept of "pushing" of "pulling" the water doesn't apply.

The return water is cooler and you are less likely to get cavitation in the pump if you are pumping the return water. That is significant with smaller high speed pumps that are used now. Also, the air vent is usually on the discharge end of the boiler which minimizes the air that will get to the circulator pump.

[fsteyer]

thanks ... I can see your points..... why are most systems set up with the pump on the supply side?
thanks again