Abstract: A fluid actuated normally closed coolant control valve. The valve comprises a valve housing, an inlet port, the inlet port configured for fluid communication with either a coolant source or a heat exchanger of a DEF tank; an outlet port configured for fluid communication with the other of the heat exchanger of a DEF tank or the coolant source; a valve chamber, a valve and an actuator configured to actuate the valve. The actuator is a fluid actuated piston. The valve is biased to a closed condition in which the flow of coolant from the inlet port to the outlet port is prevented by the valve. The valve is actuatable to an open condition in which the flow of coolant from the inlet port to the outlet port is permitted, and the valve is withdrawn from the valve chamber, wherein the flow factor for the valve is greater than 1.5.

Abstract: An example system includes a valve assembly having: (i) a plurality of ports including an inlet port, an outlet port, and a vent port, (ii) a solenoid coil having a cavity therein, (iii) an armature slidably accommodated in the cavity of the solenoid coil, (iv) a magnet fixedly disposed within the solenoid coil, wherein the magnet applies a magnetic force on the armature in a distal direction, and (v) a spring applying a biasing force on the armature in a proximal direction; and a controller sending a signal having a particular polarity to the solenoid coil such that the signal is applied to the solenoid coil for a particular period of time, and resending the signal periodically every particular time interval.

Abstract: An example method includes receiving, at a first frequency, sensor information indicative of an actual pressure level of a pilot fluid signal in a pilot line connecting an outlet port of a pilot supply valve to a pilot port of a main valve; determining an estimated pressure for the pilot fluid signal in the pilot line at a second frequency greater than the first frequency; determining a pressure estimate error based on comparing the actual pressure level to the estimated pressure; determining a pressure level error based on comparing the estimated pressure to a commanded pressure value; and operating the pilot supply valve in an open state to provide the pilot fluid signal to the pilot port of the main valve until the pressure level error is less than a threshold value.

Abstract: An example valve assembly includes a mounting plate having an inlet port configured to be fluidly coupled to a source of fluid; a pilot supply valve mounted to the mounting plate, wherein the pilot supply valve comprises (i) an inlet port fluidly coupled to the inlet port of the mounting plate, and (ii) a first outlet port configured to be fluidly coupled to a pilot port of a main valve; and a pilot exhaust valve mounted to the mounting plate, wherein the pilot exhaust valve comprises (i) a vent port, (ii) a second outlet port that is fluidly coupled to the first outlet port of the pilot supply valve.