What categories can HYDAC filter elements be divided into by installation position?

Suction filter elements are installed at the oil suction port of hydraulic pumps as primary coarse filters. Most are made of stainless steel mesh with low rated working pressure and minimal allowable differential pressure. They mainly trap large particles and iron scraps in the oil tank to prevent hard debris from entering and wearing the pump, thus protecting key pump components. Featuring large flow area and low resistance, they are generally not equipped with bypass valves. Clogging will easily lead to insufficient oil suction and pump cavitation, so regular inspection and cleaning are required.

Pressure line filter elements are fitted on high-pressure oil circuits such as the pump outlet and the front of valve manifolds. Mostly high-pressure glass fiber elements, their rated working pressure can reach 210 bar, and reinforced versions are available for higher pressure conditions. Serving as fine filters with a beta value of no less than 200, they remove fine particles to protect precision components including servo valves and proportional valves. A built-in bypass valve comes as standard to keep the oil circuit running when differential pressure exceeds the limit.

Return line filter elements are mounted on pipelines that convey return oil back to the tank, acting as terminal filters of the hydraulic system. They operate under low pressure and are commonly glass fiber elements. They collect wear debris and sludge generated throughout the circuit to avoid secondary contamination of hydraulic oil. Being the most widely used type, their replacement cycle can be adjusted according to on-site contamination levels.

Off-line bypass filter elements work independently of the main circuit in an offline circulation mode, primarily for systems with stringent oil cleanliness requirements. They continuously purify oil in the tank to reduce overall contamination and ease the load on main line filters. Usually equipped with high-precision media, they are ideal for large hydraulic equipment operating 24/7. In practical use, select the appropriate filter type based on installation position, pressure rating and filtration accuracy.