Schneider Electric MK-6821 Pneumatic Valve Actuator 8-13 PSI Spring Return

The Schneider Electric (Barber Colman) MK-6821 is a proportional control pneumatic valve actuator designed for precise control of hot water and chilled water valves in HVAC and building automation systems. This spring return actuator features a large 50 square inch effective diaphragm area, delivering reliable performance in demanding commercial and industrial applications.

Key Features:

• Operating pressure range: 8-13 PSI for proportional control
• 50 square inch (323 cm²) effective diaphragm area for powerful actuation
• Spring return mechanism for fail-safe operation
• Linear movement with 1-inch nominal stroke
• 1/8-inch NPT air connection for pneumatic control
• NEMA 1 rated enclosure for indoor commercial use
• Compatible with 2-1/2 to 4-inch valve sizes

This actuator is part of the proven MK-6XXX Series and is ideal for proportional pneumatic control applications requiring large actuator force. The spring return design ensures the valve returns to a safe position during power or air supply failure, making it suitable for critical HVAC control systems.