Hydraulic oil filter, classified by its material, can be made from filtering paper, chemical fiber (glass fiber, sintered metal fiber felt, polypropylene fiber and polyester fiber), screen-type filter (stainless steel screen mesh), wire-gap filter (normally copper or aluminum line).
Hydraulic oil filter is suitable for strong acid, strong base and organic solvent filtration, the structure is pleated with bigger filtering area, low working pressure, large dirty hold and longer service life, there are many models and specifications for selection.
In selection of hydraulic oil filters, here are some points you need to note:
Filter Rating
Hydraulic oil purity is necessarily to be considered for each hydraulic system, and it is also the original purpose we use hydraulic oil filter, so filter rating is the first point we need to consider.
Since that, somebody would assume that we just choose hydraulic oil filters with highest rating to solve the problem. It is good to used high rating filter, but here we have a misunderstanding. Hydraulic oil filter required by hydraulic system is not necessarily High but Proper. Normally hydraulic oil filter with high rating has low flow rate, moreover, in different installation joints, filter rating required are different, and it is also easy to be blocked. If high rating filter necessarily need to be used, that would mean low flow rate, short service life and frequent change-outs.

Hydraulic Oil Filter Strength
The strength of hydraulic oil filter has to meet its operating demand. Pipeline hydraulic oil filter has to bear downstream high pressure after pump, oil suction filter should bear pressure without deforming, without transforming filter rating, meanwhile keep its oil flow rate.
Oil used in some hydraulic systems is some certain corrosive, whether to use common hydraulic oil filter or anticorrosive one should be considered as per site conditions.

Installation
The function and rating of hydraulic oil filter installed in different joints, without idea about its position, it would be hard to select a hydraulic oil filter, this point is very important.

With all these information above, it would be helpful for you to select and use hydraulic oil filter.