Multipass Performance of Different Medias in Aircraft Hydraulic Filters

The aircraft filters have to be designed to cater for high reliability and stringent environmental conditions. The performance of filter is decided based on the filter media and its rating. Filter rating is evaluated using multi pass test under constant flow conditions. Generally there are two types of medias used in development of aircraft hydraulic filters (I)glass fibre media and (II)stainless steel mesh media. Glass fiber media is consided as absolute rated and possess high filtration efficiency compared to the stainless steel mesh media. Stainless steel mesh media filters are of non disposable in nature and possess nominal filter rating. The present paper describes the comparitive study of two filter medias and evaluation of filter rating using multi pass test.