LIFE OF HYDRAULIC CYLINDERS


The life of hydraulic cylinders depends on a large number of variables. As a general rule hydraulic cylinders are very robust and durable actuators, that can also be repaired quickly and easily.

With proper design, dimensioning and operation, hydraulic cylinders last a long time. However, the following should always be taken into account in operation:

  • Avoid pressure spikes (caused by the pump or the application of external forces).
  • Avoid transverse forces, or absorb them using suitable guides
  • Do not overheat seals
  • Protect piston rod from mechanical damage/scoring (assembly, maintenance, environmental conditions)
  • No contamination (from inside via abrasion and corrosion or from outside via worn seals, ambient dirt, metal chips or adding new unfiltered oil)
  • No water in the oil
  • No air in the hydraulic system
  • Spark-over on piston rod

As soon as scoring appears or is visible on a piston rod, that is a sign that the operating conditions or the design are not-optimal. Furthermore the seals will also have sustained damage.

Contaminants in the hydraulic fluid will permanently accentuate the effects of scoring and damage to seals. Therefore hydraulic systems should have appropriate filter equipment that keeps solid contaminants to a minimum, and which also filters out any water in the oil. The corresponding reference values and system solutions can be obtained directly from the filter manufacturers.

The following basic rule applies: the higher the system pressures, the higher the oil purity should be . Therefore high-pressure systems should always satisfy purity level 14/10 according to ISO 4406.

 
Non-observance of these points may cause considerable damage to hydraulic cylinders already after a few working strokes, or even result in complete functional failure.
 As a standard at AHP Merkle all piston rods are hardened for maximum life of the hydraulic cylinders.

Hardened piston rod (AHP Merkle standard)


Non-hardened piston rod