Remember to keep things fluid

Bosch Rexroth remind industry of the importance of best practice in hydraulic fluid selection

DRIVE and control specialists Bosch Rexroth have restated the importance of choosing correctly rated hydraulic fluids to optimize performance and safety in mobile applications.

The advice comes as the company issues its own Fluid Rating List recommending the most appropriate high-performance fluids for use with its hydraulic pumps and motors. This complements the requirements of international standards ISO6473-4 and ISO4006.

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

Kevin Follows, technical support manager for mobile applications at Bosch Rexroth, explained: ‘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, optimizing 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.’

According to Mr Follows, viscosity, operating temperature, environmental factors, manufacturers’ recommendations and materials compatibility are the key criteria on which the fluid selection decision should be based.

He continued: ‘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.’