Abstract: Urea solution pumps having leakage bypass flowpaths and methods of operating the same are disclosed. Certain embodiments are pump apparatuses including an inlet passage in flow communication with a source of urea solution and a pump chamber, an outlet passage in flow communication with the pump chamber and an exhaust after treatment system, a diaphragm facing the pump chamber and coupled with an actuator, a first housing member coupled with a second housing member form a seal around the pumping chamber, a leak collection chamber surrounding the seal, and a return passage in flow communication with the leak collection chamber and the inlet passage. Urea solution that leaks from the pump chamber past the seal is received by the leak collection chamber and flows through the return passage to the pump inlet passage.

Abstract: A reductant delivery system is provided for delivery of reductant to an engine exhaust aftertreatment system that is heated during cold temperature conditions. A heat exchange fluid flows through a heat exchange circuit that provides a flow path from the heat source to the doser, from the doser to the reductant storage tank, and from the reductant storage tank to the heat source. A control valve controls the flow of the heat exchange fluid in the heat exchange circuit so that at least one heat exchange cycle includes a circulation period that increases the temperature of the reductant in the doser and storage tank and a termination period where circulation is stopped until reductant temperature in the doser reaches a lower limit.

Abstract: A reductant delivery system is provided for delivery of reductant to an engine exhaust aftertreatment system that is heated during cold temperature conditions. A heat exchange fluid flows through a heat exchange circuit that provides a flow path from the heat source to the doser, from the doser to the reductant storage tank, and from the reductant storage tank to the heat source. A control valve controls the flow of the heat exchange fluid in the heat exchange circuit so that at least one heat exchange cycle includes a circulation period that increases the temperature of the reductant in the doser and storage tank and a termination period where circulation is stopped until reductant temperature in the doser reaches a lower limit.

Abstract: A reductant delivery system is provided for delivery of reductant to an engine exhaust aftertreatment system that is heated during cold temperature conditions. A heat exchange fluid flows through a heat exchange circuit that provides a flow path from the heat source to the doser, from the doser to the reductant storage tank, and from the reductant storage tank to the heat source. A control valve controls the flow of the heat exchange fluid in the heat exchange circuit so that at least one heat exchange cycle includes a circulation period that increases the temperature of the reductant in the doser and storage tank and a termination period where circulation is stopped until reductant temperature in the doser reaches a lower limit.

Abstract: Urea solution pumps having leakage bypass flowpaths and methods of operating the same are disclosed. Certain embodiments are pump apparatuses including an inlet passage in flow communication with a source of urea solution and a pump chamber, an outlet passage in flow communication with the pump chamber and an exhaust after treatment system, a diaphragm facing the pump chamber and coupled with an actuator, a first housing member coupled with a second housing member form a seal around the pumping chamber, a leak collection chamber surrounding the seal, and a return passage in flow communication with the leak collection chamber and the inlet passage. Urea solution that leaks from the pump chamber past the seal is received by the leak collection chamber and flows through the return passage to the pump inlet passage.

Abstract: A reductant delivery system is provided for delivery of reductant to an engine exhaust aftertreatment system that is heated during cold temperature conditions. A heat exchange fluid flows through a heat exchange circuit that provides a flow path from the heat source to the doser, from the doser to the reductant storage tank, and from the reductant storage tank to the heat source. A control valve controls the flow of the heat exchange fluid in the heat exchange circuit so that at least one heat exchange cycle includes a circulation period that increases the temperature of the reductant in the doser and storage tank and a termination period where circulation is stopped until reductant temperature in the doser reaches a lower limit.