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

Silence is Golden (Yellow) for Berners-Schober
“The pumps are much quieter as is the circulating water
Dirt Separator Piping
Install the Spirotrap® typically ahead of the system component being protected, such as the boiler in this drawing.
Mercy Medical Center - Des Moines, IA
High velocity 18" combination air eliminator and dirt separator.
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.