Cylinder Selection

1.  Compile Application Requirements
To determine the appropriate Cable Cylinder model for an application, compile the following information:

• Available pressure (PSI)
• Weight of load (lbs. or kgs.)
• Orientation of load (lbs. or kgs.)
• Velocity of load (in./sec. or mm/sec.)
• Stroke length (in. or mm)

• Consult the Theoretical Force vs. Pressure charts
• Cross reference the load force (or load weight if force is not known) and the available operating pressure. If the inersection falls below the diagonal line, the actuator will accommodate the application. If the intersection is above the diagonal line, a larger cylinder bore size should be considered.

NOTE: Additional force may be required to obtain the necessary acceleration for vertical or horizontal loads.

For Double Purchase cable cylinders, select a bore size that will accommodate twice the load force.

• Consult the Cushion Data chart for the model selected. The velocities listed on the cushion charts are final or cushion impact velocities. On applications where the internal cushions are to be used, be sure the actual, final or impact velocity is known. If the velocity is not known, use of limit switches with valve deceleration circuits or shock absorbers should be considered. Cross-reference the final velocity and weight of the load. If the intersection is below the diagonal lines, the internal cushions on the cable cylinder may be used. If the point falls above the dashed diagonal line or if the velocity is not known, use deceleration circuits, external shock absorbers or select a larger cylinder with greater cushion capacity. On high-cyclic applications, use of external stops is strongly recommended.
  

4.  Determine the Maximum Stroke Lengths for Full Manual Cable Adjustment
Once you have selected the proper bore size for your application and determine the cylinder's cushion capacity, you need to determine the physical stroke length limitation of the cylinder. Refer to the Maximum Stroke Lengths table in the selection example at the bottom of this page to find the bore size selected and its maximum stroke length.

NOTE: Maximum recommended stroke length for full manual cable adjustment is the maximum stroke length at which the cables can be properly proof-loaded, pretensioned and maintained at the required tension by manually adjusting the clevis terminal lock nuts. Maximum stroke length is based on the cylinder's maximum pressure rating.

If the stroke length for your application falls within the maximum stroke length at full manual cable adjustment, your model selection is complete.

IMPORTANT NOTE: Once a cylinder is installed in an application, but before putting it into service, the cables must be proof-loaded and pretensioned for proper operation. Refer to Application Guidelines for proof-loading and pretensioning methods.

If your stroke length is beyond the maximum stroke lengths shown, you have two options available. 

1. Increase the maximum stroke length of the selected cylinder size by the percentage of the pressure differential between the cylinder's actual operating pressure and the cylinder's maximum rated operating pressure.
   
                                         Example: If the cylinder selected is a
                                                       DP15 (1-1/2-inch bore):
                                                       Actual PSI:          80
                                                       Max. PSI:           100
                                                       Differential:        20%
                                         20% x 126 in. (maximum stroke)= 25.2 in.
                                              25.2 + 126 = 151.2 in. (12.6 feet)   
                              
2. If your required stroke length is still more than the increased stroke length determined from option "1.", an automatic tensioner (AT) or multiple tensioners may be required. For maximum stroke lengths when using auto tensioners, refer to the chart on the "Automatic Tensioners" page.