Breather Valve with Integrated Flame Arrester The atmospheric deflagration-proof VD/TS type PROTEGO valve is a highly developed combined pressure/vacuum relief valve for high flow capacities with an integrated Flame arrester unit. It is primarily used as a safety device for flame transmission proof in- and outbreathing on tanks, containers and process engineering apparatus. The valve offers reliable protection against excess pressure and vacuum, prevents the inbreathing of air and product losses almost up to the set pressure and also protects against atmospheric deflagration. The PROTEGO Flame arrester unit is designed to achieve minimum pressure drop with maximum safety. The PROTEGO VD/TS device is available for substances from explosion groups IIA to IIB 3 (NEC group D to C MESG ≥ 0.65 mm