What Does “Oil Filtration” Mean?

At first glance, the question “What is oil filtration” seems to be easy to answer.  There are however, no hard and fast answers to this question  because of the great amount of variety of oil found on the world oil market.  If for a moment you were to put aside the broad variety of oils on the market, we can answer the question in the following way: Oil filtration is a method of removing contaminants either in a suspended state either to protect the equipment, or to extend the service life of the oil.   Let’s discuss it in more detail.

What does filtration mean?

There are two types of oil filtration:
  • Primary purification; and
  • Secondary purification;
Primary purification is used to protect equipment.  The filtering devices are mounted by the equipment producers. From a technical point of view, this type of filtration is realized with a by-pass valve that lets the oil flow past and through the valve.  This device removes impurities of more than 25 microns. This kind of filtration is called “coarse” filtration due to the size of contaminants being filtered.  The primarily task of this kind of filtration is to prevent equipment damage by coarse particles.  The filtering devices are mounted in the lubrication circuit of the equipment or in the delivery line that leads to the lubrication point.  Sometimes they are be mounted in the return pipeline that goes from the lubrication point depending on the equipment manufacturer’s design and engineering concept. Filters are usually made of porous materials.  The internal bypass valve opens when filters become saturated with contaminants and/or when pressure exceeds preset limits.   Non-filtered oil then flows out of the filter and is circulated into the equipment. A secondary filtration is applied in order to extend the service life of oil through by purifying and restoring the oil’s performance characteristcs.  Often, a secondary filtration method is called “oil purification.”  The main benefit of this kind of filtration is that it extends the service life of the oil as well as the equipment.  Sometimes, producers provide equipment with a built-in secondary filtration system, but often secondary filtration is considered to be an optional pice of equipment. The following are the most widespread methods of secondary filtration:
  • Centrifuge filtration;
  • Magnetic and vacuum cleanings;
  • Dehydration; and
  • Application of filtering materials.
Secondary filtration is able to clean oil to the lowest ISO purity class standard.  Even if seconday filtration systems are in place, it is not recommended to change or remove the the primary filtration system mounted by the equipment manufacturer. GlobeCore has a wide spectrum of filtering systems designed and intended for the purification of lubricating oils and fluids.  These systems provide for the service life extension of oil as well as the oil-filled equipment. Taking into consideration the high prices for oil filled equipment and the cost of oil changes as well as possible downtimes, it is reasonable to mount GlobeCore’s secondary filtration units on your existing equipment.