Pneumatic Damper Actuator 8-13, Universal Mount
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D-4073 Pneumatic Actuator
The D-4073 Pneumatic Actuator is a multipurpose positioning device used to accurately position small dampers primarily on unit ventilator, Variable Air Volume (VAV), terminal units, and small ventilating dampers in response to output signals of a pneumatic controller or electro-pneumatic transducer. The actuator is also recommended for use on other air flow control dampers, in interior locations, up to a maximum area of 6.75 square feet for proportional volume control and 11.7 square feet for two position actuation provided that the torque requirements are compatible with the specific application. The D-4073 is a direct replacement for existing D-3073 actuators and a functional replacement for former D-251 actuators.
Features and Benefits
When an 8 to 13 psig spring range is used with proportional control, the damper size is limited to 6.75 square feet maximum. As a two position control, damper size is limited to 11.7 square feet. Three nominal spring ranges are available: 3 to 7 psi, 5 to 10 psi, and 8 to 13 psi. The control air pressure for normal HVAC operation is 0-20 psig.
The D-4073 incorporates several internal and external features that add functional flexibility. A 2-way swivel connection on the actuator cylinder head provides non-binding movement. All actuators have a telescoping piston rod for easy linkage of the damper for attachment points up to 8-3/4 inches (222 mm) away from the face of the actuator. A swivel ball joint and slotted crank arm connector are furnished on all actuators for optional methods of linkage to the damper.
Air pressure from a pneumatic controller is applied to the diaphragm of the actuator, which moves the piston against the forces of the internal spring and the load. The external load force shifts the operating range from the nominal spring range. The piston will move to a position where the applied force and the spring plus external forces are in equilibrium. However, with a pilot positioner added, the piston will move to a position proportional to the control signal regardless of the load.
The D-4073 can be mounted in a variety of positions to operate unit ventilators, VAV boxes as well as normally open or normally closed dampers. The D-4073 with universal mounting bracket contains all parts required for the actuator to be mounted inside or outside the duct with D-1300 series dampers. The auxiliary mounting bracket assembly facilitates applying the D-4073 actuator to allied equipment manufacturer’s products, and non-Johnson Controls installations for actuator conversions. These assemblies are furnished with a crank arm linkage and pedestal style bracket. Refer to the installation instructions packaged with the actuator for complete recommended procedures.
Other mountings are available to suit special applications. The linkage face of the actuator contains four mounting holes to facilitate other brackets or competitive conversions. A 1/8 inch NPT straight barbed fitting for 5/32 or 1/4 inch O.D. polytubing is furnished for standard HVAC installation. A stop screw kit is available for special applications to limit the power stroke of the actuator when required. A 4 foot (122 cm) linkage rod is also available for special applications to reach extended linkage when required. Where precision sequential operation is desired, or additional positioning power is necessary, use a D-9502 positioner. Up to four more D-4073 actuators
may be slaved from one pilot for coupled dampers.
Field repairs can not be made. This part must be replaced.
Replaces Part Numbers: D-4073-2