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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.
Unit of Measure

Inventory

Inventory

 N/A {0}

Specifications

Series

 N/A Vacuum Breaker

Size

 N/A 2.50 inDN 65

Nominal Size (MNPT) A

 N/A 2.50 in

Unthreaded Inlet Bore B

 N/A 1.50 in38 mm

Style

 N/A BSSV6

Friction Loss (Feet of Pipe)

 N/A 12.05

Friction Loss (Meter of Pipe)

 N/A 3.7
Valve Cracking Pressure1 N/A 0.16 psi0.011 bar4.5 in.water114 mm.water8.4 mmHg

Valve Cracking Pressure Tolerance

 N/A ±10%

Approx. Net Weight Each

 N/A 2.25 lb1 kg
Cold Working Pressure2
N/A 0 psig1100 psig0 barg75.8 barg

ENDS

 N/A NPT (Threaded)

Cv

 N/A 36

Materials of Construction

Seat

 N/A 316 SS

Disc

 N/A 316 SS

Guard

 N/A CF8M

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
ASTM4 N/A 303 SS not acceptable for CRN

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.
  • 4 Contact DFT for acceptable material