A method for operating a conveying device for an aqueous urea solution in a motor vehicle, having a pump for conveying the aqueous urea solution, wherein the aqueous urea solution is conveyed from a tank along a pressure line to an injector, wherein the injector is arranged on an exhaust gas line and is designed to inject the aqueous urea solution into the exhaust gas line. The conveying speed of the pump is controlled depending on the opening operations and closing operations of the injector and/or the pressure conditions resulting therefrom in the conveying section between the pump and the injector.

A device for releasing reactant (R) into the exhaust gas stream (A) of an internal combustion engine includes a reactant injection unit (20), a reactant delivery unit (12) for delivering reactant (R) from a reactant reservoir (14) to the reactant injection unit (20), a heating unit (18) for heating reactant (R) delivered by the reactant delivery unit (12) to the reactant injection unit (20). An actuating unit (32) actuates the reactant delivery unit (12), the heating unit (18) and the reactant injection unit (20). An overpressure valve (26) or/and a pressure storage unit (30) is provided downstream of the reactant delivery unit (12).

Component of tank of liquid additive of system for treating exhaust gases of internal combustion engine, has body positioned in fluid-tight way at opening of the tank and incorporates plurality of functional devices for managing liquid additive to be delivered to treatment system. Body of tank component is moulded using plastic material chemically resistant to liquid additive and is provided with at least one passageway for liquid additive. The plurality of functional devices comprises pump and pressure sensor having pressure-sensitive element. Passageway comprises delivery path for the liquid additive, which is defined at least in part in first wall of body of tank component and has inlet end configured for connection to delivery duct of the pump. Defined at outer side of first wall is at least one seat for positioning at least one part of pressure sensor. Moreover defined in the first wall is at least one passage for setting delivery path for liquid additive in fluid communication with sensitive element of pressure sensor.

A method for measuring the injected mass of a fluid containing urea using a system for injecting the fluid into an exhaust system of a vehicle, in which injecting the fluid includes sequences of series of injections of fluid contained in an accumulator between sequences for starting the pump upon detection of a pressure below a threshold P.sub.ON and sequences for stopping the pump upon detection of a pressure above a threshold P.sub.OFF, the method particularly includes computing the injected mass using the complete circuit hydraulic stiffness, based on the hydraulic stiffness K.sub.D of the accumulator and the hydraulic stiffness K.sub.I of the remainder of the circuit, and includes comparing the computed injected mass with a setpoint injected mass.

A connection unit having a connector and at least one fluid line that is connected to the connector, wherein the connector has at least two connection ends and a connector section that connects the connection ends to one another. A fluid line end of a fluid line engages with at least one connection end of the connector. At least one compensation element is connected to the fluid line in the area of the fluid line end of the fluid line, the compensation element being supportable on at least one support stop via at least one spring element. Due to a pressure increase in the connector section, the compensation element is movable against the restoring force of the spring element in the direction of the support stop, with an increase in the internal volume of the connector section.

A diesel exhaust fluid (DEF) delivery system and method for operating same. The method includes controlling a pump to operate at an idle speed to pressurize a pressure line. The method includes controlling a backflow dosing module (BFDM) valve to open to allow an amount of the DEF to flow into a fluid storage tank through a backflow line. The method includes determining a dosing request, a first dosing actuation request for the first dosing valve and a second dosing actuation request for the second dosing valve based on the dosing request. The method includes, when a sum of the first and second dosing actuation requests is less than 100%, controlling the BFDM valve to close when either of the first and second dosing valves is open; and controlling the BFDM valve to open when the first dosing valve is closed and the second dosing valve is closed.

The invention relates to an expansion body having an equalization chamber, which is separated by an elastic diaphragm from a fluid which flows through part of the expansion body. A mechanical spring applies an additional spring force to the diaphragm, wherein the spring has mechanical prestress. In addition, the invention relates to an SCR system with such an expansion body, and a method for monitoring a pressure sensor in such a SCR system with an expansion body. The method comprises the following steps: first, an anticipated characteristic pressure at which the spring force of the spring of the expansion body is overcome is defined by setting the prestress of the spring in the expansion body.

An aftertreatment system for treating constituents of an exhaust gas includes: a housing defining a first internal volume and a second internal volume; an oxidation catalyst in the first internal volume and extending along a first axis, the oxidation catalyst configured to receive at least a portion of the exhaust gas via an inlet conduit fluidly coupled to the oxidation catalyst; a filter in the first internal volume and extending along a second axis parallel to and offset from the first axis, wherein an outlet of the filter is disposed within the second internal volume and configured to emit the exhaust gas into the second internal volume; at least one selective catalytic reduction (SCR) catalyst in the second internal volume and extending along a third axis that is perpendicular to the first axis; and a decomposition tube in the second internal volume in a direction parallel to the third axis.

A suction tube for a urea sensor installed in a urea tank comprises a suction pipe and a cover. The suction pipe has a suction opening and a hole extending through a wall of the suction pipe. The cover is disposed on an outside of the suction pipe and covers the hole. When there is an under-pressure in the suction pipe compared to the urea tank, the cover abuts the suction pipe and seals the hole. When there is an overpressure in the suction pipe compared to the urea tank, the cover deforms and allows an excess urea solution to escape through the hole and flow back into the urea tank.

A device for releasing reactant (R) into the exhaust gas stream (A) of an internal combustion engine includes a reactant injection unit (20), a reactant delivery unit (12) for delivering reactant (R) from a reactant reservoir (14) to the reactant injection unit (20), a heating unit (18) for heating reactant (R) delivered by the reactant delivery unit (12) to the reactant injection unit (20). An actuating unit (32) actuates the reactant delivery unit (12), the heating unit (18) and the reactant injection unit (20). An overpressure valve (26) or/and a pressure storage unit (30) is provided downstream of the reactant delivery unit (12).