Hydraulic systems can be pure oil, oil water emulsion or water based. In each case the basic applications for filtration are the same:
Suction Strainers protect pumps from large potentially damaging items.
Tank top filters prevent the ingress of solids during filling or during the fluctuating tank levels during use with the addition of a desiccant they can significantly reduce the ingress of water into a system Pressure line filters are placed between the pump and the point of use. They prevent contamination of downstream components and thus ensure efficient control and motive power, they normally have a high pressure rating and relatively low solids holding capacity.
Return line filters are placed between point of use and the pump, they prevent pump damage and tank contamination. They are normally low pressure units.
Off line units are also employed and are dealt with in a separate section.
Strainers are employed to prevent gross contaminants and Ultraviolet systems can be used to reduce microbial loads in emulsion systems.
Total Filtration can meet all of these requirements