METHOD FOR OPERATING REAGENT METERING SYSTEM AS WELL AS DEVICE AND LINE NETWORK FOR PERFORMING THE METHOD

The invention relates to a method of operating a reagent quantification system (10), which is arranged to transport a reagent (14) in a transport direction via a line network (N) towards a metering element (D1). The metering element (D1) quantifies the reagent to an exhaust gas passage (16) of an internal combustion engine (18) at the upstream before a SCR catalyst (20). A line network has a mainline (H), which is connected to a first line branch (L1) and at least one another line branch (L2) through a branch element (A) for transmitting reagents. After the dosing operation ends, the quantitative element placed after the first line branch and the other metering element reagent placed after the another line branch are at least partially removed from the line network, so that the first linebranch and/or another line branch extracts only the amount of reagent that can block the ventilation of the branch element. There is also a line network, a control device (26) with which the reagentmetering system is operated