Patent ID: 8863501

Claim:
An injection system for injecting a fluid into an exhaust tract, the injection system comprising at least two modules and at least one pressure compensation volume ( 44 , 46 , 48 , 54 , 56 , 58 ); each module comprises at least one injection unit ( 40 , 50 , 60 ) operable to inject the fluid into the exhaust tract, and the pressure compensation volume ( 44 , 46 , 48 , 54 , 56 , 58 ) is operable to feed the fluid to at least one of the modules and connects at least two of the modules hydraulically to one another, wherein at least the first module comprises a metering unit ( 10 , 20 , 30 ; 21 , 31 ) for metering the fluid, wherein the metering unit ( 10 , 20 , 30 ) comprises a cutoff valve ( 12 , 22 , 32 ) for cutting off the fluid feed and a metering valve ( 14 , 24 , 34 ) for metering the fluid, and wherein an outlet of the cutoff valve ( 12 , 22 , 32 ) is hydraulically connected to an inlet of the metering valve ( 14 , 24 , 34 ), and wherein an inlet of the second module is hydraulically connected via the pressure compensation volume ( 44 , 46 ) to an outlet of a cutoff valve ( 12 ) of the first module.