How can I combat corrosion in hydraulic oil reservoirs?

Aluminized Steel Hydraulic Oil Reservoir

This 109-gallon capacity hydraulic oil reservoir is fabricated from aluminized steel and is used in an aerial work platform bucket truck. It includes a sight gage, filler-breather, and filter.

By Ryan McCarty, The IFH Group

Hydraulic reservoirs in mobile equipment can be prone to corrosion when humid air is drawn in when the oil level drops. Once moist air gets into the reservoir, water can condense on the interior walls when the ambient temperature drops. Desiccant breathers can be specified to filter and dry ambient air drawn into the reservoir. However, the desiccant has a finite service life, so if the breather is not changed at recommended intervals, moisture will be drawn in unimpeded. The condensate, ultimately, will enter the hydraulic system and pose several problems.

The condensate will also adhere to the interior surfaces of the reservoir, which could lead to rust deposits that can also enter the hydraulic system. These deposits can cause problems of their own, including premature wear to components, clogging of filters and orifices, and valve malfunctions.

Reservoirs made of aluminized steel can help prevent corrosion if moisture does get into the reservoir. Aluminized steel is sheet carbon steel that is hot-dip-coated on both sides with an aluminum-silicon alloy to avoid the contamination problems inherent to uncoated steels. Essentially, aluminized steel combines the corrosion resistance of aluminum with the higher mechanical strength — and lower cost — of steel. Aluminized steel reservoirs are compatible with virtually all petroleum-based and synthetic fluids while also providing protection from atmospheric corrosion.

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