Install the Spirovent® at the point of lowest solubility, which is the place in the system where the temperature is the highest and pressure the lowest. Note as well to always "pump away" from the expansion tank, never towards it.

Related Work

Eastern Illinois University - Charleston, IL
After having tried numerous other methods, the first Spirovent was installed in Carman Hall to deal with a long history of no heat calls and clogging valves.
Red Rock Casino Resort Spa - Las Vegas, NV
24" high velocity combination air eliminator / dirt separator.
North Mississippi Medical Center - Tupelo, MS
High velocity 18" combination air eliminator and dirt separator.
Maine Medical Center - Augusta, ME
Three of the larger Spirotherm® products on this multi-system project.