Schneider Electric (Barber Colman) MK-4601 Actuator

The Schneider Electric MK-4601 (formerly Barber Colman) is a heavy-duty pneumatic valve actuator designed for proportional control of valves requiring linear movement. Featuring an 11 square inch effective area diaphragm, this spring return unit operates on a 3-6 psi nominal spring range, providing reliable mechanical positioning in HVAC pneumatic control systems. This model is technically identical to MK-4601-0-0-2 and includes a NEMA 1 enclosure to protect internal components from environmental debris. With a 1/2" nominal stroke and a 1/8" NPT air connection, it integrates seamlessly into existing air lines. For contractors managing steam or water flow applications, the MK-4601 ensures precise throttling and fail-safe operation upon loss of control air. High-grade die-cast aluminum construction resists corrosion, maintaining performance in demanding mechanical rooms. Whether replacing a legacy Barber Colman actuator or installing a new Schneider setup, the MK-4601 remains an industry standard for durable linear pneumatic actuators.

• Precision Throttling: The 11 sq. in. diaphragm provides consistent force for accurate proportional valve control across the 3-6 psi range.
• Standardized Fit: 1/2-inch stroke and 1/8" NPT port allow for drop-in replacement of older MK-4601 pneumatic actuators.
• Fail-Safe Logic: Integral spring return mechanism ensures the valve moves to its default position during a power or pressure failure.
• Rugged Construction: NEMA 1 rated housing protects against dust and contact, extending the service life in commercial HVAC environments.

Is the MK-4601 interchangeable with the MK-4601-0-0-2?
Yes, those part numbers refer to the same technical specifications and are physically identical units.

What is the effective diaphragm area for this actuator?
The MK-4601 features an 11 square inch diaphragm, which is standard for mid-sized linear valve applications.

Can this actuator be used with non-Schneider valves?
While optimized for Schneider Electric and Barber Colman valve bodies, it can be mounted to other valves provided the linkage and stroke requirements match.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.