Advanced Search by Product Number
Find My Check Valve
DFT® Vacuum Breakers 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.

Standard Features:
  • 1" to 4" Size (Outside Diameter)
  • 450 to 6000 CWP
  • Threaded O.D. (MNPT)
  • Unthreaded Inlet Bore
  • Stainless Steel Construction
  • Spring-Assisted Silent Closing
  • Horizontal or Vertical Installation
  • Tight Shutoff - Lapped Disc & Seat
  • Easy Maintenance
  • Versatile
Request Information
Unit of Measure
Items
Vacuum Breaker Threaded In-Line Check Valves

1" 316 SS BSSV6 Style Vacuum Breaker Threaded In-Line Check Valve
1 303 SS BSSV Style Vacuum Breaker Threaded In-Line Check Valve"

1" 303 SS BSSV Style Light Spring Vacuum Breaker Threaded In-Line Check Valve
1 303 SS BSSV Style Vacuum Breaker Threaded In-Line Check Valve"

1" 303 SS BSSV Style Vacuum Breaker Threaded In-Line Check Valve
1 303 SS BSSV Style Vacuum Breaker Threaded In-Line Check Valve"

1 1/2" 303 SS BSSV Style Vacuum Breaker Threaded In-Line Check Valve
Vacuum Breaker Threaded In-Line Check Valves

1 1/2" 316 SS BSSV6 Style Vacuum Breaker Threaded In-Line Check Valve
Series N/A Vacuum Breaker
Size N/A 1.00 inDN 25 N/A 1.00 inDN 25 N/A 1.00 inDN 25 N/A 1.50 inDN 40 N/A 1.50 inDN 40
Nominal Size (MNPT) A N/A 1.00 in N/A 1.00 in N/A 1.00 in N/A 1.50 in N/A 1.50 in
Unthreaded Inlet Bore B N/A 0.56 in14 mm N/A 0.56 in14 mm N/A 0.56 in14 mm N/A 0.88 in22 mm N/A 0.88 in22 mm
Style N/A BSSV6 N/A BSSV N/A BSSV N/A BSSV N/A BSSV6
Friction Loss (Feet of Pipe) N/A 7 N/A 7 N/A 7 N/A 6 N/A 6
Friction Loss (Meter of Pipe) N/A 2.1 N/A 2.1 N/A 2.1 N/A 1.8 N/A 1.8
Valve Cracking Pressure1 N/A 0.6 psi0.041 bar16.7 in.water424 mm.water31.1 mmHg N/A 0.24 psi0.017 bar6.6 in.water167 mm.water12.4 mmHg N/A 0.6 psi0.041 bar16.7 in.water424 mm.water31.1 mmHg N/A 0.44 psi0.03 bar12.1 in.water307 mm.water22.6 mmHg N/A 0.44 psi0.03 bar12.1 in.water307 mm.water22.6 mmHg
Valve Cracking Pressure Tolerance N/A ±10%
Approx. Net Weight Each N/A 0.38 lb0.2 kg N/A 0.38 lb0.2 kg N/A 0.38 lb0.2 kg N/A 0.88 lb0.4 kg N/A 0.88 lb0.4 kg
Cold Working Pressure2
N/A 0 psig6000 psig0 barg414 barg N/A 0 psig2500 psig0 barg172 barg N/A 0 psig2500 psig0 barg172 barg N/A 0 psig2000 psig0 barg138 barg N/A 0 psig5500 psig0 barg379 barg
Seat N/A 316 SS N/A 303 SS N/A 303 SS N/A 303 SS N/A 316 SS
Disc N/A 316 SS
Guard N/A CF8M N/A 303 SS N/A 303 SS N/A CF8M N/A CF8M
Spring N/A 316 SS
Retaining Ring N/A 316 SS
Available Soft Seat Materials3 N/A Buna-N (-70 to 250ºF) EPDM (-75 to 300ºF) TFE®-Viton® (-40 to 400ºF) Viton® (-40 to 400ºF) Zelon® (37 to 470ºF)
ENDS N/A NPT (Threaded)
ANSI N/A B1.20.1
MSS N/A SP-25
ASTM4 N/A 303 SS not acceptable for CRN N/A N/A N/A N/A 303 SS not acceptable for CRN
Cv N/A 5.8 N/A 5.8 N/A 5.8 N/A 13.2 N/A 13.2
Applications N/A Antisiphon Applications Boiler Feed & Discharge Heat Exchangers Irrigation System Jacketed Pans Steam Coils Steam Mains Steam Systems Sterilizing Chambers Storage Ressels Tanks
  • 1 Cracking pressure for vertical flow will be slightly different: upward flow, slightly higher; downward flow, slightly less.
  • 2 Contingent on service ratings of matching pipe and fittings.
  • 3 Buna-N and Viton are not suitable for steam service.
  • 4 Contact DFT for acceptable material