Honeywell MP918B1105 High Force Pneumatic Damper Actuator 8-13 PSI Spring Range

The Honeywell MP918B1105 is a high-force pneumatic damper actuator designed for proportional control of medium to large-size dampers in HVAC systems. This rolling diaphragm, piston-type actuator delivers reliable performance with a 3.5-inch stroke for precise damper blade positioning and airflow control.

Key Specifications:

• Spring range: 8-13 PSI for consistent operation
• Stroke length: 3.5 inches
• Diaphragm area: 23.8 square inches (neoprene rolling type)
• Torque output: 333 lb-in at midstroke, 208 lb-in extended (at 18 PSI)
• Operating temperature: -20°F to 158°F
• Maximum pressure rating: 25 PSI
• Air connection: Barbed 1/4-inch fitting

Features:

• Rolling diaphragm operation for extended service life
• Low friction shaft bearing for smooth operation
• Close tolerance on operating range and stroke
• Internal normally open mounting bracket and pushrod assembly included
• Non-overlapping spring ranges ideal for sequencing applications
• Versatile mounting and connecting hardware options

This actuator is suitable for variable air volume (VAV) systems, mixing boxes, and other applications requiring high-force damper control. The MP918B series offers replacement capability for Johnson, Powers, Robertshaw, Barber-Colman, and older Honeywell actuator models.