When designing and constructing a hydraulic tank there are a lot of things to consider. One of them is to ensure an air-sucking vortex, like that you see when water goes down a drain, can not develop at the pump intake line penetration. Doing the following will ensure that it doesn’t:

–Locate the intake penetration at least five times its inside diameter from the nearest reservoir wall, and no less than half its inside diameter, (but at least 100 mm or 4″), off the bottom.

–Ensure the intake penetration always remains submerged by at least twice its inside diameter.

–Size the intake line so that fluid velocity is no more than 1.2 m/sec (4 ft/sec), and preferably slower.… continue reading »

Water removal filters are one way of removing water from hydraulic oil. Generally speaking, these filters are best suited to removing small amounts of water. If the oil is contaminated with a large amount of water, centrifuging or evaporation techniques such as vacuum dehydration and head-space flush should be considered.

There are two types of water removal filters: coalescing and polymeric. Coalescing filters work by passing the oil through a dense, inorganic fiber mat. The fibers break the oil film, which allows non-emulsified (free) water to adhere to and be retained by the fibers. As water droplets accumulate in the filter mat, they coalesce into larger droplets which drain down through the fibers into a collector, which is periodically drained.… continue reading »

Off-line filtration, whether permanently installed on a hydraulic system, or effected by the temporary installation of a portable filter cart, is a powerful bazooka in the contamination control effort.

Without interfering with the operation of the equipment, the oil can be kept clean, in the former case, with full-time, offline filtration. Or, the oil can be flushed periodically with a portable rig, in the latter.

When using a filter cart, the oil is normally taken from the hydraulic tank, filtered and returned to the hydraulic tank. Which means the cleanliness of the newly filtered oil is diluted by the bulk volume of unfiltered oil remaining in the tank.… continue reading »