The 80% rule

When you make hydraulic setups, you should always examine the setup before using it. You want to look for ways to protect yourself and others, and ways to protect your equipment and other property.

Try to create the ideal setup. Since few things in life are ideal, following the 80% rule will result in more stable setups and prolong the life of your equipment. The 80% rule applies to cylinder stroke and cylinder capacity.

Cylinder Stroke – The first is that leaving distance between the stop ring and the bearing reduces side loading force resulting in a more stable cylinder.
The second is that you avoid damaging the stop ring by running the plunger all the way up and hitting the stop ring with the bearing.

Cylinder Capacity – The reason for applying the 80% rule to cylinder capacity (tonnage) is that most loads are not lifted on their true center. This results in side loading of the cylinder. Allowing for a safety factor is the simplest way to compensate for the off-center characteristics of a one-point lift.