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

Purdue University - West Lafayette, IN
Spirovent exceeds expectations and leads the University to purchase and install (32) additional units at the village.
Waukesha Memorial Hospital
The Spirovent was selected and installed to prevent dirt and sediment in the existing system from reaching a new addition and improvements went even beyond that.
South Point Hotel, Casino & Spa - Las Vegas, NV
Custom fabricated 24" high velocity combination air eliminator / dirt separator for the hot water system and custom fabricated 30" high velocity air / dirt for chilled water.
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.