The DPL system doses lubricant with a progres- sive piston movement. Every piston controls the following one in a sequence obtained through a single delivery flow. This system is highly qualified for dosing oil and grease to one or more journals or bearing. Each piston is in series with the component before or the one after it and therefore malfunctioning of one of these causes stopping of the sequence and consequently inhibiting of the system. This inhibition occurs also during any external clog- ging or when unused outlet are plugged.