Hydraulic fluids change with the times

The right chemistry minimizes operating problems and saves money. Hydraulic and Industrial Gear Additives Using the wrong hydraulic fluid can have severe and costly consequences, such as catastrophic pump failure. Hydraulic fluids are the workhorses of hydraulic systems. They transmit power, lubricate and help cool equipment, and prevent rust and corrosion. But hydraulic fluids are not one-size-fits-all commodities. Fluid manufacturers choose from an array of base oils and additives to tailor characteristics to specific applications. For instance, some fluids resist oxidation and thermal degradation in high-temperature equipment, such as plastic injection-molding machines. Others need to resist fire, biodegrade, or operate in wet conditions, requiring different formulations. Not all additive packages or combinations provide equal performance, so it is important to understand how additives work in specific base oils. Reputable suppliers conduct laboratory bench testing and hydraulic-pump testing before introducing fluids into the marketplace. And make no mistake, there are financial consequences to using the wrong fluid. In addition to the cost of prematurely replacing the fluid, there are expenses associated with the labor to drain old fluid and add new, lost productivity while equipment is down, fluid disposal costs, and the negative effects of wear and corrosion on equipment. Here are three key parameters to know and discuss with fluid suppliers. This is the most important property to consider when selecting a fluid. Viscosity is the strength of the fluid's cohesive force. It determines fluid friction and the drag moving parts exert, which pulls fluid between metal surfaces. Viscosity at the equipment's operating temperature determines the rate at which fluid flows through a bearing — and with it bearing friction and load-carrying capacity. Fluid with the proper viscosity quickly distributes to moving surfaces — a key to long pump life. Fluid with lower-than-recommended viscosity can cause internal pump leakage and raise