Barber-Coleman Company MK-3101-0-2 Damper Actuator

The Barber Colman MK-3101-0-2 Damper Actuator is a compact pneumatic damper actuator designed for HVAC applications such as dampers, mixing boxes, and air valves, delivering reliable two-position ON/OFF control with proportional characteristics and a spring-return action. It operates at 3 to 8 psig and, for the MK-3101-0-2 variant, specifies a 3.5-inch stroke with a 1/8 in NPT air inlet and an approximate 8 in² (about 52 cm²) effective actuation area. The unit weighs about 2.72 kg and carries a NEMA 1 protection rating, making it suitable for indoor, non-hazardous environments where robust damper positioning is required. This model is identified as part of the MK-3101 family, known for 2-position (ON/OFF) operation with proportional control and spring return, providing fail-safe damper positioning in heating, ventilating, and air conditioning systems. The MK-3101-0-2 variant is documented to have a 3–8 psi spring range, 3.5-inch stroke, and approximately 21 lb-in of torque, reflecting its capability to move moderate-variable dampers with precise travel. Typical applications include regulating airflow in commercial buildings, balancing rooms, and zoning systems where dependable, non-electrical override positioning is desired and where a compact pneumatic solution is preferred. Note that, according to manufacturer records, the MK-3101-0-2 variant has been discontinued, which can affect availability and substitution considerations for new projects.