Actuator Sizing and Selection

Sizing & Selecting ActuatorsSelecting 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: Step #2: Step #3: Calculate the total louver area in square feet (length x width) Calculate the total linear (running) feet of actuator rod 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 0” to 5’-6” 5’-7” to 11’-0” 11’-1” to 16’-6” 16’-7” to 22’-0” Number of Actuator Rods 1 2 3 4Number of actuator rods x louver length (or height) = Total linear feet of actuator rod Max. Capacity Louver Area Ft^2 88 Ft2 187 Ft2 291 Ft2 440 Ft2 660 Ft2 75 Ft2 37 Ft2 150 Ft2 75 Ft2 660 Ft2 Max. Capacity Actuator Rod Lin. Ft. 16’ 34’ 53’Johnson:D-4073 (-4 w/positioner, -5 w/o positioner) 8-13 psi spring D-3153 (-4 w/positioner, -5 w/o positioner) 8-13 psi spring D3244 (-3 w/positioner, -4 w/o positioner) 8-13 psi springFisher:Model 656-30 Model 656-40 80’ 120’Durastroke:Model 60, 6-30 psi spring Model 65, 3-15 psi spring Model 120, 6-30 spring Model 125, 3-15 spring Model 1000 – 2000