Actuator Sizing and Selection.12-22-08 (EN)

Sizing & Selecting Actuators Selecting a pneumatic actuator is a three step process done by evaluating the total area of a louver assembly, the total length of actuator rod in that assembly and considering the final orientation of the louver when attached to the cooler. Step #1: Calculate the total louver area in square feet (length x width) Step #2: Calculate the total linear (running) feet of actuator rod Step #3: Apply the appropriate orientation factor to actuator capacities shown below and make the selection that satisfies both are and actuator rod calculations. IMPORTANT NOTES: 1. Orientation Adjustments (except for 740 Series louvers) a. Horizontal louvers:

1.0 multiplier on actuator area and actuator rod capacities b. Vertical louvers: .75 multiplier on actuator area and actuator rod capacities 2. For 740 Series louvers a. Maximum allowable total torque tube length is 20 feet b. Maximum allowable distance from actuator to end of louver is 12 feet c. Maximum allowable blade length is 36 inches Excluding 740 Series louvers, maximum allowable blade length is 66”. Using that as a guide, simple actuator rod estimations are shown: Total Louver Width Number of Actuator Rods 0” to 5’-6” 1 5’-7” to 11’-0” 2 11’-1” to 16’-6” 3 16’-7” to 22’-0” 4 Number of actuator rods x louver length (or height) = Total linear feet of actuator rod Max. Capacity Max.

Capacity Louver Area Actuator Rod Johnson: Ft^2 Lin. Ft. D-4073 (-4 w/positioner, -5 w/o positioner) 8-13 psi spring 88 Ft 2 16’ D-3153 (-4 w/positioner, -5 w/o positioner) 8-13 psi spring 187 Ft 2 34’ D3244 (-3 w/positioner, -4 w/o positioner) 8-13 psi spring 291 Ft 2 53’ Fisher: Model 656-30 440 Ft 2 80’ Model 656-40 660 Ft 2 120’ Durastroke: Model 60, 6-30 psi spring 75 Ft 2 25’ Model 65, 3-15 psi spring 37 Ft 2 12’ Model 120, 6-30 spring 150 Ft 2 50’ Model 125, 3-15 spring 75 Ft 2 25’ Model 1000 – 2000 660 Ft 2 120’ 1550 S. 81 st W. Avenue • Tulsa, OK 74127 Office: 918-241-0264 • Fax: 918-241-0270 • www.airtechproducts.com

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