Product Critical Technical Advantages
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Reverse-Acting Performance: The 667-4 is engineered for applications requiring an upward stem movement upon increased air signal. This is a fundamental requirement for fail-closed valve configurations, where the internal spring ensures the valve remains seated if the pneumatic supply is interrupted.
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Tubeless Integration with Integral Air Passage: One of the standout features of the 667-4 is the integral air passage. When paired with Fisher FIELDVUE™ digital valve controllers, this design eliminates the need for external tubing and fittings. By removing these external components, the actuator reduces potential leak points and simplifies maintenance in high-vibration environments.
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Optimized Response and Thrust: The actuator uses a shallow casing on the pressure side to minimize internal air volume, which significantly reduces response time. Furthermore, its molded diaphragm travels in a deep casing to minimize area change throughout the stroke, ensuring consistent and maximum thrust for its specific size.
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Simplified Mounting and Alignment: The 667-4 incorporates an integral mounting pad, eliminating the traditional mounting bracket. This reduces the number of parts required for assembly and ensures a more rigid, precise alignment between the actuator and the control instrument.
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Rugged Seismic and Corrosion Protection: Constructed from thick-walled cast iron and steel, the 667-4 provides the structural stability needed for demanding industrial sites. This heavy-duty build offers excellent protection against atmospheric corrosion and mechanical stress, common in refineries and power plants.
Technical Specifications and Capabilities
| Feature | Details |
| Actuation Action | Reverse-Acting (Air-to-Push Up) |
| Mounting System | Integral Pad (for reduced part count) |
| Air Connection | Tubeless (Internal) or Traditional External Tubing |
| Material Build | High-strength Cast Iron and Steel |
| Diaphragm | Molded for consistent thrust throughout travel |
| Versatility | Available with travel stops and manual handwheels |
Primary Applications
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Petrochemical Refining: Precise management of hydrocarbon flows where fail-safe closing is a safety priority.
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Power Generation: Automated control of high-pressure steam and water lines where response time is critical.
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Chemical Processing: Throttling control for corrosive media, utilizing the robust construction of the 667-4.
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General Industry: Reliable pneumatic actuation for a variety of sliding-stem control valve applications.
