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Fisher™ Vent Diffusers
Fisher 6012 vent diffusers offer proven noise and vibration control in sky vent applications.
A vent diffuser places back pressure on the control valve while venting process to the atmosphere and shares the total pressure drop with the vent valve. This reduces the vent valve noise and noise at the atmospheric vent point. Fisher 6013 vent diffusers come with an outer shell attached for use in sky vent applications in power plants.
Fisher™ Vent Diffusers


NPS 2, NPS 3, NPS 4, NPS 6, NPS 8, NPS 10, NPS 12, NPS 14, NPS 16, NPS 18, NPS 20, NPS 24, NPS 26
Critical Service
Noise Abatement
Carbon Steel, Stainless, Alloy
Operating Temperature
Standard Temperature, High Temperature
Process Connection Type
Raised Face, Flanged, RTJ, Butt Weld
Valve Size
NPS 2, NPS 3, NPS 4, NPS 6, NPS 8, NPS 10, NPS 12, NPS 14, NPS 16, NPS 18, NPS 20, NPS 24, NPS 26
Valve Size Standard
Other Configurations
Contact your local Emerson business partner or sales office to learn about additional specifications or options for this product.


  • The diffuser concept is used in several unique versions, providing optimum solutions for various applications. The diffuser need not be installed adjacent to the control valve.
  • A properly selected diffuser-valve combination can result in up to 40 dBA noise reduction.
  • A diffuser-valve combination retains the pressure/flow control associated with a standard control valve. Just as important, it controls the generation of potentially damaging noise and vibration.
  • All Fisher diffusers, both inline and vent, are ruggedly-built, static devices requiring no maintenance after installation. These features combine to offer increased noise control at a minimum investment.