Advanced Search by Product Number
Find My Check Valve
Request Information
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.
0.24 psi (6.5 inches of water) cracking pressure spring, (±10%)
Unit of Measure

Inventory

Inventory

 N/A {0}

Specifications

Series

 N/A Vacuum Breaker

Size

 N/A 1.00 inDN 25

Nominal Size (MNPT) A

 N/A 1.00 in

Unthreaded Inlet Bore B

 N/A 0.56 in14 mm

Style

 N/A BSSV

Friction Loss (Feet of Pipe)

 N/A 7

Friction Loss (Meter of Pipe)

 N/A 2.1
Valve Cracking Pressure1 N/A 0.24 psi0.017 bar6.6 in.water167 mm.water12.4 mmHg

Valve Cracking Pressure Tolerance

 N/A ±10%

Approx. Net Weight Each

 N/A 0.38 lb0.2 kg
Cold Working Pressure2
N/A 0 psig2500 psig0 barg172 barg

ENDS

 N/A NPT (Threaded)

Cv

 N/A 5.8

Materials of Construction

Seat

 N/A 303 SS

Disc

 N/A 316 SS

Guard

 N/A 303 SS

Spring

 N/A 316 SS

Retaining Ring

 N/A 316 SS

Available Soft Seat Materials

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)

Codes and Standards

ANSI

 N/A B1.20.1

MSS

 N/A SP-25

Features

N/A

  • 1" to 4" size
  • 450 to 6000 CWP
  • Threaded O.D. (MNPT)
  • Unthreaded inlet bore
  • Stainless Steel Construction
  • Spring-assisted silent closing
  • Horizontal or vertical installation
  • Tight shut-off - lapped disc & seat
  • Easy maintenance
  • Versatile

Options

N/A

  • Inconel® 750 Spring
  • Soft seat

Application

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.