: Always isolate the control valve from process pressure and release all pressure from both sides of the valve body before maintenance. Hazardous Areas

actuators, the 3590 series converts a 4–20 mA DC signal into a pneumatic output pressure that drives the actuator. Key Specifications Input Signal 4-20 mA DC, 10-50 mA DC, or split ranges Output Signal Pneumatic pressure required for 7/16 to 4 1/8 inch travel Supply Pressure

Proper installation is critical to prevent "hunting" or sluggish response. According to the Fisher 3590 manual, these steps are foundational: