A lubricant applicator unit for pressure relief valves for a system for applying pressure relief valves to packaging during a packaging process, including a vacuum applicator for temporarily separating layers of the valve when the lubricant is applied. A pressurized nozzle sprays or atomizes the lubricant into the valve opening. Graphite suspended in liquid silicone is used as the lubricant; it is recirculated in a reservoir to keep the graphite in suspension. Optical sensors check for valves before the entrance to, and after exit from, the vacuum applicator.