A question I’m asked regularly is “What is the best way to test the integrity of the piston seal in a double-acting hydraulic cylinder?”

There is a simple bench-test for doing this but it involves the intensification of pressure in the cylinder. While the test procedure is safe if you understand the concept of intensification in a hydraulic cylinder – it is inherently dangerous if you don’t. In this post I will explain the dangers of intensification in a double-acting cylinder and in my next post I will explain the test procedure.

Force produced by a hydraulic cylinder is a product of pressure and area (F = p x A).… continue reading »

In a previous blog post I discussed the true cost of hydraulic oil leaks. In the case of oil leaks, the cost areas that need to be considered include:

Make-up fluid;
Clean-up;
Disposal;
Contaminant ingress; and
Safety.

But what about hydraulics’ fluid power cousin – pneumatics? One of the advantages that pneumatics has over hydraulics is its clean-ness. Air leaks are much easier to ignore than oil leaks because they don’t draw attention to themselves in the same way. You don’t need to worry yourself with clean-up and disposal costs. Contaminant ingression is possible, but is generally not a major concern.… continue reading »

Hydraulic hose has a finite service life, which can be reduced by a number of factors. From a maintenance perspective, little or no attention is usually paid to the hoses on a hydraulic machine until a failure occurs. And hydraulic hose failures cost more than the replacement hose. Additional costs can include:

–Clean up, disposal and replacement of lost hydraulic oil.
–Collateral damage to other components, e.g. a hose failure on a hydrostatic transmission can result in loss of charge pressure and cavitation damage to the transmission pump and/or motor.
–Possible damage caused by the ingression of contaminants.
–Machine downtime.

Focus on the following issue to extend hydraulic hose life and minimize the costs associated with hydraulic hose failures:

External damage

Hydraulic hose manufacturers estimate that 80% of hose failures are attributable to external physical damage through pulling, kinking, crushing or abrasion of the hose.… continue reading »