Vacuum Breaker

DFT Vacuum Breakers (BSSV) provide effective protection against collapse of pressure vessels, tanks and rolls. They prevent condensate “back-up” when equipment is shut down or inlet steam is reduced by modulating control valves. In piping systems, DFT Vacuum Breakers are used to break siphons, prevent pipe collapse during transient pressure drops, and to provide addition of air on the downstream side of check valves to dampen water hammer.



  • 1” to 4” line size (MNPT)
  • 450 to 6000 CWP
  • Threaded O.D. (MNPT)
  • Unthreaded inlet bore
  • Stainless steel construction
  • Edge-guided disc
  • Spring assisted silent closing, non-slam
  • Tight shutoff – lapped disc & seat
  • Horizontal or vertical installation
  • Easy maintenance
  • Versatile
  • Options:
    • Inconel§ X-750 spring
    • Soft seat