Hydraulic filter performance evaluation has traditionally relied on steady-state multi-pass flow testing as defined in ISO 16889:2022, which enables reproducible assessment of particulate removal efficiency and contaminant capacity under controlled static flow conditions. However, many hydraulic systems operate under dynamic duty cycles characterized by fluctuating flow rates and transient loading conditions, which can significantly influence pressure drop development, particle capture mechanisms, and dust holding capacity (DHC). The ISO 23369:2022 standard introduces a cyclic flow multi-pass test methodology to better reflect these operational realities.

At Alkegen, our research and development team has completed a systematic blind comparison study of static and cyclic flow testing on finished hydraulic filter cartridges sourced from both the open market as well as manufactured by Alkegen using internally developed filter materials. All cartridges were evaluated within a blind study framework to ensure objective comparison.

All cartridges shared standardized form factors, and testing followed ISO 16889 for static evaluation and ISO 23369 for cyclic flow assessment. Key performance metrics evaluated, included: differential pressure evolution, contaminant concentration profiles, particle removal efficiency, micron rating stability over filter life, and Dirt Holding Capacity (DHC).

Results demonstrate that ...