Hydraulic Matters

Palma de Mallorca

This time we will talk about hydraulics and the importance of having a good and correct filter system fitted in the system controlling your yacht!

It all started around 1950, when the military airplanes ‘all of a sudden started to fall down from the sky’. Nobody knew at that time what was really going on.

The engineers took the systems apart, had a good look with their eyes, could not find anything obviously wrong, put them back together... Back in the air, the planes fell down even more frequently... The more they took them apart, the worse it got!

After some thinking and using a magnifying glass, they all agreed. A simple filter, similar to a coffee filter, was put in on the return line, and finally the planes stayed up in the air for much longer. Since that moment, the filter producers have not stopped researching and developing.

There is nothing worse than opening up a hydraulic system in, for example, a dirty and filthy shipyard where sanding and painting is going on amongst sand blasting etc.

Some numbers

A good pair of fresh eyes can see down to 40 um. 1 um = 1 micron = 0.001 mm. A human hair is about 70 um.

Today's Load Sense systems (LS), most commonly using variable axial piston pumps, require a 10 um absolute filtration grade. (Servo valves about 3 um.) Not to be confused with nominal filtration grades!

Most problems in the systems occur just after refits and services.

99% of people use a ‘half filthy’ funnel to top up the system instead of a small portable filling unit, which quite easily cleans the oil before it destroys the components.

Especially new oil is NOT clean enough in most cases, even straight from a new bucket!

If the system needs opening, the correct end plug MUST be fitted immediately.

For a couple of reasons: one is to prevent dirt and particles, the other is safety and health.

Way too many accidents are caused by neglecting the power of hydraulics.

We at HSM have an understanding of the needs and have extensive experience in the field.

Cheers / HSM

Hydraulic Services Mallorca S.L.

hydraulicservicesmallorca.com