Technical Specifications Category Specification Model 667-40 Type Pneumatic Spring-Return Scotch-Yoke Rotary Actuator Action Spring-Return (Single-Acting) Travel 90 degrees standard. Spring Code -40 (This defines the spring range and torque output). Air Signal / Supply Pressure The "-40" code corresponds to a specific air pressure range required to stroke the actuator against the spring force. For a -40 spring, this is typically in the range of 20-45 psig. The exact start and end pressures must be confirmed from the official Fisher torque chart. Torque Output The torque is proportional to air pressure and is defined by the spring code and actuator size. The 667 series provides high torque outputs suitable for larger valves. Air Connections 1/2" NPT standard. Mounting Standardized mounting to Fisher and other manufacturers' rotary valves via a drive shaft and coupling. Yoke Material Cast Iron or Coated Cast Iron for corrosion resistance. Spring Housing Material Cast Iron. Temperature Limits Standard: -20°F to +150°F (-29°C to +66°C).