Hydraulic systems are essential for many industrial and commercial operations, and the selection of the right lubricant is paramount to ensure their proper functioning. Three common varieties of hydraulic fluids found on the market today are those derived from petroleum, those derived from water and those that are synthetic. These fluids have multiple purposes, such as providing energy transmission, lubrication, heat transfer and pollution control. When selecting a lubricant, it is important to consider viscosity, sealing compatibility, base material and additive package. Most hydraulic systems can work with many different fluids, including multigrade engine oil, automatic transmission fluid, and more conventional anti-wear (AW) hydraulic oil.
Buna-n (nitrile) is the most common type of material used in fast-acting couplings and provides an excellent seal for use with crude oil, gasoline, propane, petroleum oils and water. It works best in temperatures that range from 40 to 250 degrees Fahrenheit. The hose is an important part of a hydraulic system as its flexibility allows components to be placed in the most efficient or convenient places. Most of the metal tubes on the high-pressure side of the hydraulic system will be made of stainless steel or steel. The component manufacturer will provide and install the high-pressure side tube and the tube fings used on the high-pressure side of the system will generally be 37-degree fings.
The return lines are usually plastic tubes with compression connections. When selecting a hydraulic fluid, it is important to consider the size and use of the equipment as well as how it will be used. DIN 51524; HLP-D fluids are a class of hydraulic anti-wear fluids that contain detergents and dispersants; these fluids are approved by most major manufacturers of hydraulic components. Successful hydraulic operations require the careful selection of hydraulic fluids that meet the demands of the system. Allow for possible shortening of the hose during operation by making the hose lengths slightly longer than the actual distance between the two connections. Changes in hose length when pressurized range from 2% to 4% while hydraulic mechanisms are in operation.
No hydraulic system can function properly without seals that keep hydraulic fluid in the system when the system is under pressure.