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, while the oil passes through. As … 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 … continue reading »
Specific heat is a numeric value which refers to the amount of heat required to raise a set quantity of a substance by a fixed temperature. For example, pure water has a specific heat of 1. This means one calorie will raise the temperature of one gram of water by one degree C. Or, in U.S. units, one BTU will raise the temperature of one pound of water by one degree F.
Note that regardless of the system of units used, the numeric value of a substance’s specific heat is the same. And all other substances are referenced to the … continue reading »