How to determine whether a HYDAC filter element needs to be replaced?

Differential pressure serves as the primary and most accurate judgment criterion. The differential pressure gauge or switch equipped on the equipment is the key monitoring device. An abnormally high initial differential pressure of a new filter indicates problems with model selection, installation or hydraulic oil, which must be inspected and rectified. During operation, replace the filter immediately once the differential pressure hits 2.0~3.5 bar for return line elements and 5.0 bar for high-pressure elements and triggers the alarm. If the pressure further rises to the bypass valve cracking pressure (3~4 bar for return line filters and 6 bar for high-pressure filters), the filter media is severely clogged and the filtration function fails. Shut down the equipment for urgent replacement, and prolonged operation relying on the bypass valve is strictly prohibited.

The rated service life is taken as a supplementary reference. Under standard working conditions, high-pressure glass fiber elements shall be replaced after 2,000~3,000 hours of service, and return line glass fiber elements after 2,500~3,500 hours. Timely replacement is recommended even without differential pressure alarms to avoid natural degradation of filtration performance. Sintered stainless steel elements are reusable after cleaning, yet they need complete replacement after a total service time of 8,000~10,000 hours regardless of their condition. The replacement cycle shall be halved under harsh conditions such as new equipment commissioning, water-contaminated oil and high-dust environments.

Visual and component inspection is also necessary. Directly replace the filter if cracks or debonding are found on end caps, or if seals suffer aging, deformation and leakage, as well as distortion of filter frames, media damage and fiber shedding, regardless of service hours and differential pressure.

Additionally, monitor the operating status of the hydraulic system. Sluggish equipment movement, increased noise, frequent component wear and aggravated internal leakage are mostly caused by damaged filter media that allows contaminants to bypass. In such cases, disassemble, inspect and replace the filter without delay.