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Single-Acting Spring Diaphragm Actuators (DSA)

The DSA-Series single-acting spring diaphragm actuators by Master Flo are engineered for robust, long-lasting performance. These actuators feature a generous diaphragm area, allowing operation at low pneumatic pressures, while an opposing spring ensures fail-closed (standard) or optional fail-open action. You can mount various positioners and instruments directly to the actuator for added flexibility.

Tailored Performance for Your Needs

Choose from 4 diaphragm sizes and a range of springs to meet your specific thrust requirements. Additional options such as manual handwheel overrides, adjustable travel stops, and special materials are available to tailor the actuator to your exact needs. Plus, positioners can be selected to meet various hazardous-area certification requirements.

Key Features:

  • Reliability: Rugged construction with minimal moving parts ensures a long service life with minimal maintenance.
  • Interchangeability: Actuator yokes incorporate standard industry mounting bosses, allowing for universal interchangeability.
  • Protective Coatings: External surfaces are powder coated for maximum protection against harsh environments, and special coatings like offshore epoxy are also available.
  • Instrument Mounting: Kits are available with mounting options for most commercial positioners, promoting field standardization.

Operating Medium

  • Instrument air
  • sweet instrument gas also available

Fail Action

  • Spring Fail Close
  • Spring Fail Open
  • Fail Last

Control Signal (positioner dependent)

  • 4–20 mA
  • HART
  • Fieldbus
  • Profibus

Feedback Signal (positioner dependent)

  • 4–20 mA
  • HART
  • Fieldbus
  • Profibus

Maximum Supply Pressure

  • DSA069: 70 psig (4.8 barg)
  • DSA105: 65 psig (4.5 barg)
  • DSA156: 55 psig (3.8 barg)
  • DSA220 & DSA2204: 50 psig (3.4 barg)

Diaphragm Area (in² / cm²)

  • DSA069: 69 / 445
  • DSA105: 105 / 677
  • DSA156: 156 / 1006
  • DSA220 & DSA2204: 220 / 1419

Hazardous Area Certification (positioner dependent)

  • CSA/FM/UL: Explosion Proof or Intrinsically Safe
  • ATEX/IEC: Intrinsically Safe or Flameproof

Operating Pressure

  • 3–15 psig (0.2–1.0 barg)
  • 6–30 psig (0.4–2.0 barg)

Operating Temperature

  • Standard: -40 to 180 F (-40 to 82 C)

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