Helpful Hints - Peninsular Configurator

Model MH and Model LM NFPA Pneumatic Cylinders

"Selecting the Correct Bore Size"

By knowing the answer to the below questions, you will be in a better position to make the correct decision in determining the cylinder bore size to select for your application. Note, when reviewing the Air Cylinder Force Chart below, you will see that a cylinder has less force on the retracted (pull) stroke than it does on the extended (push) stroke. That occurs because the piston rod reduces the surface area of the piston on the retracted stroke of the cylinder.

  1. Determine the load (amount of weight) that is to be moved.

  2. Is the movement of this load traveling in a horizontal or vertical direction?

  3. Is the stroke travel unsupported or is it guided or supported in any way?

  4. Is the load being moved in only one direction or is it being moved in both directions
    of the cylinder stroke? If in only one direction, is it on the push (extended stroke) or
    the pull (retracted stroke) of the cylinder.

  5. You must know the air line pressure that is working the cylinder.

The chart below shows the amount of force generated by an air cylinder in both the push (extended) and pull (retracted) directions at various air line pressures. For safety and performance reasons a cylinder should be rated at a percentage of the force as stated on the charts based upon your knowledge of the five issues noted above. For example:  if you need to move a load weighing 545 lbs. in both directions of the cylinder with a working air line pressure of 80 PSI you probably would not select a 3 ¼” bore cylinder for your application even though the chart indicates that this can be done in both directions (with a 1 3/8" diameter rod). Using your knowledge of the above five issues, a good decision might be to introduce a safety factor of 70% into your decision by selecting a 4” bore cylinder (with a 1 3/8" diameter rod) which can safely push and pull the 545 lb. required load. (887 X 70% = 621 lbs.) Remember, line pressures do not always stay constant and line pressure may drop in any application for a number of logical reasons. The selection of the correct diameter piston rod also enters into this decision process so please refer to our helpful hints when making your decision to select the correct piston rod diameter.

Confused? If you need any assistance please feel free to call us toll free at (800) 526-7968 in the USA or Canada or at (586) 775-7211. You may also e-mail us at sales@peninsularcylinders.com

 

Air Cylinder Force Chart for Selecting the Correct Cylinder

 Bore Size for Model MH and Model LM Cylinders

 


PUSH  (Extended Stroke)

PULL  (Retracted Stroke)

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