Vaccum Relief Vacuum relief valve - D 12.4 N | KITO Armaturen Vacuum relief valve - D 12.4 N | KITO Armaturen KITO® vacuum relief valves KITO® vacuum relief valves are used where closed systems are being emptied or cooled by their local environment, preventing, for example, negative pressure to damage storage tanks. View Flanged PN 10 PN 16 PN 40 DIN 1.4571 Steel