The importance of best practice in hydraulic fluid selection

A vital component in hydraulic systems, hydraulic fluids perform multiple tasks, including power transmission, lubrication, and friction and wear reduction, as well as minimising the effects of heat and contaminants.

Kevin Follows, Technical Support Manager, Mobile Applications at Bosch Rexroth explains: "There is an enormous range of hydraulic fluids on the market but not all of them are suitable for every application. Many are mineral oil-based but specifiers can also select from monograde, multigrade, anti-wear and fire-resistant oils. The varying components of fluids perform a multitude of tasks in protecting the system, optimising safety, performance and longevity. However, each product is designed to function optimally under certain conditions and in tandem with particular components - so specifiers would be well advised to ensure the correct product is chosen, or risk potentially costly and disruptive production issues down the line."

Follows lists viscosity, operating temperature, environmental factors, manufacturers' recommendations and materials compatibility as the key criteria on which the fluid selection decision should be based.

He continues: "Flow resistance and thermal conductivity are vital, while the effects of leakage or spillage must always be considered in these times of heightened environmental concern. Meanwhile, taking the time to understand the applications for which the fluid has been designed will go a long way towards ensuring optimal product selection.

"Combined with a clean system, a proper start-up procedure, appropriate filtration, regular condition monitoring and oil change when it contains excess water or contamination, the chosen fluid will then invariably deliver to the expectations of the user."

Follow the link for further information and to download Rexroth's Fluid Rating List.