Here at Gerrard Hydraulics, when we show people our workshop, the usual first reaction is “I could eat my dinner off that floor!” As it happens, we don’t eat our dinners off our floors; or indeed any other meals. And there’s a lot else in our shop that we’d like to show you. But there’s no denying that we’ve got a thing about cleanliness. But an obsession with hygiene that would have ordinary people seeking clinical help is a perfectly sane response to the challenges of hydraulics.
Cleanliness is next to Godliness
Hydraulic systems, as we know, operate on the basis of Pascal’s Law, the principal effect of which is that pressure in an incompressible fluid is exerted equally throughout the body of the fluid. That means it’s always trying to escape, from anywhere it can. Impurities in tiny quantities can score the walls of cylinders or foul valve mechanisms. And because this is hydraulics, if something bad can happen, it will happen. Cleanliness is an obsession that all of us who use or work on hydraulics should share. Here are some tips for the conscientious operator.
Sources of Contamination
Mechanical wear in service – hydraulic pumps operate at quite high speeds and under considerable stress, and wear is inevitable, as is the fact that the abraded material will in the first instance enter the hydraulic fluid supply. Of course other moving components shed material through wear, but the pump is the major culprit. Modern systems often include components such as high response valves, which require cleaner fluid than items such as the pump. Keeping your filters in good shape is essential in trapping these contaminants before they get to parts of the system where they can do damage. And make sure that your filter media are of the grade specified by the machine’s manufacturer. Set up and adhere to a schedule of maintenance appropriate to the pattern of your operations. Between servicing, check fluid quality regularly.
Manufacture and Distribution of the fluid. Despite their best efforts, manufacturers never manage to produce an absolutely uncontaminated product. Hydraulic fluid is classed for purity using a system which counts the number of foreign particulate bodies of various diameters. Class numbers range from 1-12, with the lowest number representing the greatest purity. You should not assume that the oil you buy is uncontaminated, and should filter it before use.
Introduction during operation and servicing. This is where you come in, and why we keep our operation as clean as we do. When servicing in the field, your challenge is even greater. Whenever you are doing something that opens the system to the environment, make sure that environment is as clean as possible. Work in still air conditions, and thoroughly clean the region around the component you want to work on.
Keeping your fluid free of damaging impurities is a battle that never really ends; following these tips will help you keep on winning!