{HEAD ~ The reducing agent} can circulate between the delivery device and {TAIL ~ the reactant reservoir} thereby, particularly when the dosing valve is closed, preventing the reactant from freezing 
circulate between
{ HEAD ~ The reducing agent } can circulate between the delivery device and { TAIL ~ the reactant reservoir } thereby , particularly when the dosing valve is closed , preventing the reactant from freezing
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH