Schneider Electric MK4-7121 Pneumatic Damper Actuator, 8-13 PSI Spring Range

The Schneider Electric (Barber Colman) MK4-7121 is a heavy-duty pneumatic damper actuator engineered for reliable, precise damper control in commercial and industrial HVAC systems. Featuring a 20 square inch actuator diaphragm and an 8 to 13 PSI spring range, this unit delivers consistent positioning performance across a wide range of building automation applications.

Key Features

• 20 square inch actuator diaphragm for strong, responsive force output
• 8 to 13 PSI spring range for reliable spring-return positioning
• Integrated positive positioner with an adjustable 2 to 13 PSI control span for precise modulating control
• Maximum operating air pressure of 30 PSIG for compatibility with standard pneumatic control systems
• Spring-return design retracts the actuator crank arm on loss of air pressure, providing a fail-safe default position
• Crank arm output for direct linkage to damper blades

Specifications

• Brand: Schneider Electric (Barber Colman)
• Model / SKU: MK4-7121
• Actuator Type: Pneumatic Damper Actuator
• Actuator Size: 20 Square Inch
• Spring Range: 8 to 13 PSI
• Positioner Type: Positive Positioner (Adjustable)
• Control Span: Adjustable 2 to 13 PSI
• Maximum Air Pressure: 30 PSIG
• Fail-Safe Action: Spring retracts crank arm on loss of air pressure

Application

The MK4-7121 is ideal for use in pneumatic building automation and HVAC zoning systems where dependable modulating damper control is required. The adjustable positive positioner allows field technicians to fine-tune the control span to match system requirements, while the spring-return fail-safe action ensures dampers return to a safe default position during air pressure loss — a critical feature for ventilation safety and code compliance.