Technical Parameters Parameter Specification Model Fisher 655 (Direct-Acting) Fisher 655R (Reverse-Acting) Type Spring-Return Diaphragm Actuator Action Air-to-Open / Spring-to-Close Air-to-Close / Spring-to-Open Standard Signal Range 3 to 15 psig (0.2 to 1.0 bar) Supply Pressure Range Up to 45 psig (3.1 bar) for the 3-15 psig range. Spring Ranges Multiple springs available for different thrust outputs and fail-safe actions. Effective Area Varies by size. Example (Size 70): 199 in² (1284 cm²) Stem Thrust Varies by size and air pressure. Example (Size 70 at 15 psig): ~2985 lb (13280 N) Stroke Lengths Available in various standard strokes, e.g., 0.5 to 4.0 inches (12.7 to 101.6 mm). Temperature Limits -20°F to 150°F (-29°C to 66°C) with standard Buna-N diaphragm. Diaphragm Material Buna-N with nylon cloth (standard)
