• Your Single Source for Steam & Hydronic Equipment
  • Serving you with over 30 years of industry expertise.
  • Call (905) 361-0270 for info, quotations and orders.
  • Vacuum Breakers

  • Vaccum BreakersWhen a steam system shuts down, the remaining steam condenses into water, which takes up a much smaller volume than the original steam. This creates a vacuum, which can damage equipment if not relieved of in a timely way. Vacuums prevent gravity draining systems from working properly, which can lead to frozen condensate and burst piping.

    Vacuum Breakers are simple, reliable devices that provide a positive means to automatically relieve or “break” an unwanted vacuum condition.

    Available in sizes from 1/8” up to 4” NPT.

    ⅜” & ¾” NPT is also available with field adjustable range from ¼” to 20” (8 – 508mm) Hg Vacuum for use on closed vessels and piping systems to control induced vacuum within safe limits.


    • Brass, bronze or stainless steel construction with threaded connection.
    • Pre-set and adjustable models for steam or hot water use.


    • Protection of pressure vessels and piping collapse from vacuum conditions.
    • Prevention of freezing due to excess condensate remaining in the system.
    • Reduction of water hammer due to vacuum caused by control valve operation.

    TIP: You can right click and choose save-as to download the PDF to your computer.

    Product Specs

  • Available Vacuum Breakers

  • Size Model
    1/8" VB3901
    1/4" VB3902
    1/2" VB3856
    3/4" VB3875
  • NOTE: Vacuum Breakers up to 4" NPT are available. The table above is only a partial selection of Vacuum Breakers we supply. Please call to inquire.

    Keystone Steam Supplies is here to help you get the Vacuum Breakers you need.