What are the three common technical causes of excessive differential pressure for HYDAC filter elements?

There are three core technical causes for high differential pressure of HYDAC filter elements.First is improper filter selection. Without reserving over 1.2 times peak flow margin during selection, insufficient filter flow area leads to excessive oil velocity and high basic differential pressure. Blind selection of ultra-fine 3 μm or 5 μm filter media increases flow resistance due to dense pores. If viscosity rise at low temperatures is not taken into account for flow reduction, even brand-new filters exceed standard idle differential pressure, with pressure rising much faster once contaminants accumulate.

Second refers to abnormal physicochemical properties of hydraulic oil. Oil viscosity rises sharply upon cold startup and drastically increases flow resistance across filter media. Water intrusion causes oil emulsification and oxidation to form sticky sludge that tightly clogs pores far quicker than ordinary solid particles. Seal fragments and rust impurities mixed in oil continuously reduce effective flow area and drive rapid differential pressure growth.

Third lies in installation errors and system structural faults. Reversed filter installation reverses oil flow and traps contaminants inside the filter. Undersized inlet/outlet piping plus excessive elbows add pipeline pressure loss on top of element pressure drop. Stuck bypass valves fail to open for pressure relief; blocked filters cannot divert fluid, resulting in persistently high differential pressure and even pressure-induced filter medium rupture in severe cases.