A pressure output device (POD) assembly for sensing fluid pressure in a fluid processing system, is provided. This POD assembly includes a shell defining a shell interior, and a movable diaphragm disposed in the shell interior and separating the shell interior into a flow-through chamber and a pressure sensing side. A sensor port is in fluid communication with the pressure sensing side. An inlet port and an outlet port are in fluid communication with the flow-through chamber. The inlet port and the outlet port define an inlet and an outlet, respectively, of a flow- through channel that passes through the flow-through chamber. A boss protrudes from the interior wall of the shell and extends into the flow-through channel to prevent occlusion of flow under different pressure conditions within the flow-through chamber.