Schneider Electric MK-6621 Pneumatic Valve Actuator 50 sq in 8-13 PSI Spring Return

The Schneider Electric (Barber Colman) MK-6621 is a linear spring return pneumatic valve actuator designed for globe valve applications. This actuator features a 50 square inch diaphragm effective area and operates within an 8-13 PSIG spring range, making it ideal for precise proportional control in HVAC and industrial valve automation systems.

Key Specifications:

• Diaphragm effective area: 50 square inches with neoprene construction
• Stroke length: 1/2 inch for precise valve positioning
• Nominal spring range: 8-13 PSIG (additional spring ranges available)
• Pressure rating: 30 PSIG maximum
• Air connection: 1/8 inch female threaded
• Ambient temperature range: -20°F to 220°F
• NEMA 1 protection rating for indoor applications

Construction Features:

• Rugged die-cast aluminum body for durability and corrosion resistance
• Rolling diaphragm design ensures consistent performance and extended service life
• Upright mounting configuration with actuator head above horizontal centerline
• Compact footprint: 10-1/2" W x 10-1/2" D x 7-3/4" H
• Proportional control signal capability for modulating applications

This actuator is compatible with VB-7000 series valves (1-1/2" to 2" sizes) and provides reliable pneumatic actuation for globe valves in commercial and light industrial environments. The spring return feature ensures fail-safe operation, returning the valve to its default position upon air pressure loss.