Statistics show that around 70 percent of damage caused to diesel generators is the result of pollution of the hydraulic system or debris in the computer system. Any professional engineer knows that the purity of the hydraulic oil is the key to lasting performance of hydraulic machines. But cleanliness – it is not all.
It’s equally important to choose the correct hydraulic fluid and to replace it properly (and regularly). This is what we will discuss today.
So, when selecting the hydraulic fluid two options should be considered. First of all – ambient temperature during operation. Secondly – the viscosity of the fluid in the operating temperature range. The second parameter is specified in the documentation of every individual machine. Some sources state that the viscosity of the hydraulic fluid depends on the type of pump that is used in the computer system. This is not entirely correct. The viscosity at operating temperature is calculated based on the bandwidth of the narrowest station in the hydraulic system, since the hydraulic fluid must have a certain rate of flow through these channels, otherwise hydraulics won’t operate properly.
Consequently, for many construction machines, using the very same versions of hydraulic pumps different types and manufacturers of hydraulic fluid are frequently utilized.
By way of instance, in contemporary hydraulic excavators, so-called “proportional” valves with very little cross section of the channel are used. The system is quite complex, with electronic control components. If you pick the wrong viscosity of hydraulic oil to your machine, the machine will not operate at full capability.
The recommended oil type is usually indicated in the cockpit on the particular information labels or directly to the tank of this hydraulic system near the filler neck. Now the modern machines frequently recommends utilizing high viscosity grade oil HVLP. This is hydraulic oil with a more contemporary package of additives compared to in oils class HLP. Oils of this class have more stable viscosity-temperature performance, and in severe cold conditions they work better. Manufacturers of these oils suggest the temperature range from – 30 to + 60 degrees Celsius.
In addition to stable temperature characteristics …