Tag Archives: oil filtration

Oil Filtration: What Should You Know?

Almost every hydraulic and lubricating system contains some contaminants even at the beginning of its service life.  It may be metal particles originated during production or impurities that penetrated during initial assembly.  Then the number of particles only increases since they may get through vent holes, joinings or during corrective maintenance.

There have been cases when one liter of a working fluid contained 100 million particles with a size of more than 1 micron.  It has been established that about 80% of breakdowns of hydraulic and lubricating systems are caused by different contaminants that are formed as a result of jamming, bearing vibration, increased/extreme oil temperature or the absence of adequate hydraulic pressure.

It is therefore, necessary to ensure constant oil filtering by a coarse mesh filter and a superfine mesh filter.  The coarse mesh filters are able to retain particles  that are bigger than the size of the existing gaps.  Fine mesh filters remove contaminants with a size up to 5 microns reducing to zero the wear of the working surfaces. The number of unfiltered particles has also a great impact on the wear rate of the equipment.

The modern hydraulic equipment and fluid industry has established international standard ISO4406.  It is the internationally accepted standard used to rate the purity of oils and hydraulic fluids.  According to ISO4406, the amount of particles with a size of more than 5 microns and the amount of the particles with a size of more than 15 microns is determined by measuring 100 millilitres of the working fluid.

Coarse mesh filters usually retain contaminants with a size of more than 25 microns that reduces the service life of friction knots, working in a mode, determined by elastohydrodynamic lubrication.

Service life may be substantially extended by using filters with a filtration fineness of 10 microns.

In addition to removing particiulate matter through filtration, water and moisture must also be removed.  Water penetration should be also prevented since it is a dangerous impurity that can cause corrosion, favors cavitation and accelerates oil’s aging and degradation.  Additionally, water favors the sedimentation of additives, the reduction of lubricating film thickness, and the accelerated wear of the gear pump.

Intermediate Container as an Innovation of the CFU Units

In December 2014, GlobeCore started  to equip the existing mobile oil stations with an intermediate container.

GlоbeCоre has developed and implemented a new model of the CFU unit line to meet the needs of companies that have a lot of tanks with contaminated oil in their production shops.  Due to an additional intermediate container, all contaminated oil may be collected in one place to be filtered.

GlobeCore mobile oil stations, designated as CFU, are designed to remove mechanical impurities from insulating and lubricating oils.  To meet an individual customer’s order, CFU units may be fitted with filters of as much as four square meters per hour capacity (4m3) to remove  moisture.

How to Check Oil While Diagnosing Machine Equipment

The service life of modern manufacturing equipment is 60% determined by oil quality.  A wide range of negative factors that influence machine oil includes:

  1. temperature;
  2. environment;
  3. chemical interaction with other materials; and
  4. electrical fields (for dielectric oils).

If oil has lost its protective properties, it will affect the engine (namely the wear rate will increase).  You should filter oil to prevent such negative consequences.

The GlоbeCоre mobile oil stations are used for oil filtration.  They have the following performance characteristics: (1) energy efficiency; (2) cost-effectiveness and (3) a high-quality filtration process.

But, how will we know that oil needs filtration?  An incomplete oil filtration process may result in great finance expenditures.  It is therefore, a systematic monitoring of oil that is needed to detect changes of the oil’s performance characteristics.

There are two different ways of oil monitoring that depend on the kind of oil the operators want to examine.  It is therefore, desirable to follow recogized international standards concerning each specific oil type when the quality of initial oil product is to be tested and analyzed.

Regonized international standards specify the necessary performance characteristics of oil such as: (1) viscosity; (2) ignition temperature; (2) flash temperature, and (3) total base number.

The second way of testing oil is applied when you want to check the quality of oil that has been already used for some period of time.  In this case, you may also rely on parameters outlined in the international standards.  There are also other possible ways of checking the used oil.  The “tribodiagnostic” process  allows the operator to check the condition of machinery without overhaul or disassembly through the use of oil analysis.  This method however, has not gained widespread acceptance and is mostly used when examining and servicing gas-turbine engines.  The tribodiagnostic consists of the assessment of the composition and the concentration of wear products in oil using special devices (e.g. spectrometer).

The ferrography is used to determine the wear type and friction rate of the machinery.  This process consists of analysing the particle size distribution, their surface condition and the materials they are composed of.

The advantage of this method is that it can be used when working with magnetic as well as non-magnetic materials (graphite, bronze, aluminum, brass, etc.).  Infrared (IR) spectroscopy allows the operators to receive information about such important oil specifications as water content, base number, acid number, soot content, additives, and oxidation products.

The proper sampling is no less important than the analysis itself since the wrong sample may lead to an incorrect diagnosis of the equipment.

Industrial Oil: Wholesale or Retail?

The volume of oil required to be purchased is defined by the needs of the company or the facility.  Normally, a large amount of oil is purchased wholesale, while a smaller amount needed for the replacement of oil fir one or several machines, is usually purchased retail.

Based on price, it would seem that wholesale purchases are better for your company financially.  The price of a large batch of oil per liter purchased wholesale will be lower than purchasing smaller retail volumes pre liter.

There are however, problems with large amounts of oil.  Wholesale volumes of oil must be stored somewhere. Industrial oil is obviously sensitive to various contaminants such as water, particulate matter and other unwanted contaminants.  Apart from allotting storage facilities, the oil also requires constant monitoring of purity and and water content.

Purity of industrial oil purchased wholesale or in smaller retail batches can be ensured by two methods:

  • Prevention of contamination in storage; and
  • Purification of contaminated oil.

Both include a whole range of measures.  As stated above, purity of industrial oil can be ensured by prevention or purification, but the best results are achieved by combining the two.  This also allows savings of money since preventive measures require quite less investment than actual purification and regeneration.

Prevention alone however, cannot maintain industrial oil’s purity in the long run.  It requires a complex approach to transportation and storage using the following equipment:

  • air-tight tanks;
  • equipment made from non-corroding materials;
  • correct temperature in storage and transportation;
  • and the use of inert gases to fill gas space.

This increases the cost of prevention.  The goal therefore, is to reduce the amount of contaminants as much as possible in the oil going to purification devices, which finalize the required purity of the product.

The following systems from GlobeCore GmbH are recommended for the purification and regeneration of industrial oil:

●      Mobile oil unit CММ-1.7 CM;
●      Mobile oil unit CММ-3.5 CM;
●      Mobile oil unit CММ-5 CM;
●      Filter cart CFU-0.8М;
●      Filter cart CFU-1.7М, (CFU-4).

Industrial Oil Sales: Preserving the Oil’s Performance Characteristics

So, you have decided to sell industrial oil?  Let’s assume that you already have found a storage facility for the product.  One thing remains however, knowing what the consumer needs and how to provide that need.

Besides better terms of supply, lower price, and various discounts, the client is mostly interested in the quality of the product.  Industrial oil quality in our case.  The quality is a combination of many parameters and characteristics that must not fall below regulated specifications during storage, transportation and operation.

Let us look into the characteristics, which define the quality of industrial oil and are important for the client’s choice:

  • Viscosity.  This is the first thing to consider about oil.  It is very important for the use of the majority of industrial oils.  When friction parts are designed and calculated, the parameter taken into consideration is the dynamic viscosity of the oil.  This is a regulated parameter of all oil made from crude base stock.  Dynamic viscosity used be defined at between 50ºС/122ºF and 100ºС/212ºF. That has changed and now all measurements are made according to ISO 3448-75 (instead of measuring viscosity at 50ºС/122ºF, the reference temperature is now 40ºС/104ºF).  When choosing industrial oil, the buyer usually considers three critical viscosity values: optimal at working temperature, minimal at maximum working temperature and maximum at the lowest working temperature;
  • Pour Point. This parameter is defined by testing a sample of the oil.  The Pour Point is the lowest temperature that the oil will continue to flow.  This temperature does not entirely indicate the dynamics of the oil in operating conditions at low temperatures.  That is shown better by actual viscosity at a given temperature. To reduce the pour point of industrial oil, it is mixed with special additives. This parameter is meaningful to the buyer planning his storage operations, dispatch, and draining and for using the oil in low temperature environments;
  • Flashpoint. This is the temperature at which the vapor of the oil can form a flammable mixture with the air. It defines the relative fire hazard of the oil and shows the presence of volatile fractions within it.  It is measured in special open or closed type devices;
  • Ash content. This parameter indicates the amount of non-organic contaminants left after burning a sample of the industrial oil. It is expressed in percentage of weight.  If ash content of oil without additives is too high, it indicates insufficient purification.  In most cases, ash content of industrial oil is from 0.002% to 0.4%;
  • Content of particulate matter, solvents, water, water-soluble acids and bases. This indication is extremely important in controlling the oil quality after production as well as determination of its further usability.  Mobile oil purification units for treatment and regeneration of oil can significantly increase the service life of the oil and improve reliability of machinery;

In practice, GlobeCore products are used for the purification and regeneration of industrial oil.

  • Color.  The color is a visual indication of the purity of industrial oil.  It also allows the buyer to make a judgment on the oil’s origins.  Keep in mind that some additives can make the oil darker.  If the color of the oil changes during use however, this is an indirect indication of its oxidation and/or contamination;
  • Acid number. Knowing this important neutralization number allows the buyer to determine the oil’s purity as well as the stability in use and in storage.  Additives can increase the acidity of the oil, but can also increase the stability of oil for long term use and storage;
  • Sulfur content.  The amount of sulfur initially depends on the amount of sulfur in the crude base stock the oil was blended from and the degree of purification and refinement.  After purification of industrial oils made from sour crude, sulfur remains in the oil in organic compounds and under normal conditions does not cause corrosion of metals.  Sulfur may become aggressive in elevated temperatures.  The content of sulfuric compounds is higher in oil with additives. This is due to the fact that additives containing sulfur are mixed with industrial oil to increase their lubrication qualities.

Buying and Storing Transformer Oil

Purchasing transformer oil is an important financial decision for your company.  It should be done very responsibly.

First, the buyer must a choose a brand of oil.  This requires careful consideration based on the type of equipment being used and the operating conditions the oil and the oil’s abilty to meet those conditions.

Second, the cost of the oil must be considered.  A small price difference in the cost of just one liter small can turn into a significant amount of money when purchasing a large volume of oil.

There are no universal recommendations for buying transformer oil. There are however, online services allowing buyers to compare transformer oil prices from various suppliers.  It is up to the buyer to research and choose a reliable wholesale distributor or retailer.

If you have already purchased transformer oil that meets the correct specifications and quality standards, then it is time to think about oil storage.

The practical way to store the oil is to use clean and dry, steel air tight vessels.  The tanks are usually coated with an oil resistant material inside.  The outside of the tanks should have anticorrosion and light reflecting coating.  The acceptable range of temperatures for storage of transformer oil is -40ºС to +60ºС/-40ºF to +140ºF.

The vessels should be equipped with valves for filling and draining as well as a manhole for cleaning, inspection and repairs.  Breathing systems must be equipped with silica gel or zeolite cartridges that can be monitored by special monitoring devices.

Three days after putting the oil into a storage tank, samples are normally taken for laboratory analysis.  Transformer oil in storage should be tested at least once a year for the following parameters:

  •  flashpoint;
  • dielectric strength at 90ºC/194ºF;
  • water extract reaction;
  • acid neutralization number;
  • particulate matter content in mircons; and
  • free water and moisture content.

It is also recommended to test the dissipation factor at 90ºС/194ºF at least once a year.

Each time the oil is tested for quality and purity, the results must comply with the parameters of fresh transformer oil regardless of the length of storage. Otherwise, the oil must be purified and regenerated to restore the oil to its new and clean condition.

GlobeCore offers a line of oil purification units under the CMM classification. These units improve color, remove acids, bases, and other aging products from any turbine, dielectric insulating oil, and industrial oils.

One of the advantages of the GlobeCore CMM line of units is their ability to regenerate oil on an energized transformer.  Another important advantage is the ability to reactive the fuller’s earth sorbent inside the unit many times over, reducing downtime for sorbent replacement and replenishment.

After the processing of transformer oil with GlobeCore equipment, transformer insulating oil is restored to an as good as new condition.

Purchasing a GlobeCore CMM unit gives you a modern efficient machine that is easy to operate and service.  The use of GlobeCore equipment and GlobeCore Process will extend the service life of the oil and the transformer significantly.

The Transformer Insulating Oil Filtration Process

The dielectric properties of transformer oil (e.g., breakdown voltage or dielectric loss factor) can be significantly improved by degassing and the removal of water and moisture from the oil.  Only clean and uncontaminated oil with the correct specifications is suitable as the liquid insulation for electric power transformers.

Often though, even new and unused transformer oil can be considered unclean and unsafe for use in electric power transformers as the oil can become contaminated during transport from the oil producer to the transformer operator.  During the time the oil is being used in the transformer, it will absorb moisture, dirt particles, fibers, soot and other products of oil and transformer aging.

The transformer oil therefore, needs to undergo a comprehensive filtering process.  The filtering process must be able to remove contaminants that includes solids, free and dissolved water and dissolved gases.

The filtering process of transformer oil is a complex procedure of removing the above described contaminants down to acceptable levels.  In recent studies, experts have revealed that serious problems can occur when insulting oil makes contact with moisture, flammable gases, and other transformer decay products.  In order to make the necessary correction, the operator should regularly monitor the condition of the insulating oils.

Companies that produce equipment for processing transformer insulating oils, cover a wide range of services and products.  They include such things as machinery for filtering transformer oil, insulation oil cleaners, cleaning systems for lubricants, machines to filter hydraulic oil, regeneration equipment for turbine oils and other industrial oil filtering equipment.  In recent decades, there has become a comprehensive network of high-tech enterprises that operate around the world.  They provide integrated systems and parts for the implementation of the transformer oil filtering and regeneration processes.

The transformer oil filtering process is a continuous circulation of oil through purification units in a closed loop system.  The oil passes through several filters of both coarse and fine filter mediums before the system further cleans the oil through a  vacuum drying, degassing and adsorption process.  The process is designed to remove dirt, sludge, foreign particles, dissolved gas and other contaminants found in the oil.  Moreover, the filtering unit can continuously analyze and control the oil at all stages of the purification process.

All systems for filtering transformer oils should have certain safety features built in such as liquid level detectors and pressure sensors.  These safety features should be incorporated into the design of the cleaning equipment.  They are needed in order to maintain the necessary level of oil inside the transformer and to prevent oil spills

The design of filters and pumps should provide for a filtering process, vacuum and degassing process that is powerful enough to quickly and efficiently process oil, without affecting the continued operation of electric power equipment.  Assessment of the effectiveness of the process is provided with tools for monitoring flow rate.

GlobeCore does all of this and more!  GlobeCore has a line of oil processing equipment that has become the most popular and cost effective equipment in the industry.  Take a look at GlobeCore and see if your company can benefit from the GlobeCore Process!

Lightening of used oil by the UVR unit

Several types of transformer oil are produced today. They are distiinguished by raw material used in production as well as the production process. Before filling the electric equipment with oil, it must be treated by heat and vacuum. The existing regulations limit the content of water, air and particulate matter in the oil.

After filling of oil, some reduction of dielectric strenth and purity is allowed.

During operation, transformer oil accumulates contaminants, oxidation products and other undesirable components, which significantly reduce performance of the dielectric. The breakdown voltage and purity do not comply even to the reduced requirements. There is a risk of transformer failure, so used oil must be replaced with new.

What can be done with old oil? Until very recently such oil was disposed of. In practice, this method is not very profitable from the economic viewpoint. The cost of disposal is added to the cost of buying new oil. If the oil is lightened to comply with regulations, its service life can be extended. There is no need to spend money to buy new oil, and the only expense is regeneration, which is much cheaper.

GlobeCore’s UVR units are a good choice. These plants are designed for lightening, regeneration and purification not only of transformer oil, but just about any mineral oil (excluding motor oil). Besides, the units can process diesel fuel and HFO, gas condensate, gasoline, kerosene etc.

The UVR does not require any special adjustment when switching from one type of processed material to another. The unit’s processing capacity may change due to the varying viscosity and density of oil products.

Processing capacity is higher for fuels and lower for various oils.

The UVR does not require special placement, operates without noise and is energy efficient.

The unit can be operated in manual or semi-automatic mode. Operator presence is only required duroing start, stop and sorbent replacement.

The most important part, however, is that the parameters of processed oil fully comply with the existing standards and can be reused in transformers.

Oil filtration

During operation, transformer oil accumulate contaminants, which can form various chemicals. These substances reduce the oil’s performance and are, of course, undesirable.

Operation of the transformer becomes unstable. To prevent this, transformer oil is filtered and purified. Some of the methods are discussed in more detail below.

The first stage of transformer oil purification is mechanical. This is a superficial treatment to remove particulate matter and water. The next step is deeper purification performed in vacuum with heating.

The first two stages are, in fact, preliminary. The main process involves various chemicals.

One of the methods is purification of oil with a 98% sulfuric acid solution.

In comparison to other chemical purification methods, the use of sulfuric acid has a significant drawback. Beside reacting with the contaminants, the acid also adversely influecnes the structure of the oil, making it somewhat unstable. Additional processes are required to resolve that problem.

The nature of selective purification is evident from the title. Speical solvents are introduced into the oil to remove specific impurities.

De-waxing is another widely accepted process. In this process, oil is treated with special solvents: acetone, toluene, bensol etc, to remove solid contaminants.

It should be noted that chemical methods influence oil’s stability, but extend the oil’s service life at the same time.

It should also be remembered that any purification process should end with finishing purification, closing the cycle of oil processing and filtration. This is usually done by contact method.

This means that the oil is mixed with special materials, usually clay or bleaching earth. The materials are then mixed and heated. Heating facilitates acviation of all sorbents in the clay.

These absorbents capture contaminants. Deep filtration separates oil from the clay. When selecting adsorbent, it is necessary to pay attention to the content of moisture. It should be suffucient to make production efficient and to make processed oil compliant with specifications.

The most interesting technology today involves the use of bleaching clays (Fuller’s earth). Globecore manufactures a range of CMM type units for filtration of various oils with the use of Fuller’s earth. The advantages of the design are the ability of multiple reactivation of the sorbent, mobility, simplicity of operation and high quality of the output product.

Downtime is significantly reduced by the ability to reactivate the sorbent without the need for frequent replacement, thus increasing process efficiency.

Oil Purification (Filtration)

The main factor in determining the length of time to complete the purification process, is the degree or level of oil contamination.  The higher the “Acid Number” of the oil. the longer the process will take to complete.  In any case, the process should be controlled by special instruments.

Any new components installed into a hydraulic system must be just as clean or more clean as the ones already installed.  Component manufacturers are obligated to provide information on the purity of each component.  In case of hydraulic tank contamination, it must be cleaned during oil processing.  At the end of the process, the purity of oil will only be as clean as the cleanliness of the tank’s internal surfaces.  If hydraulic liquid is replaced by another, insoluble and not mixed with the original liquid, the time of purification increases drastically.

The Purification Process requires checking all filters and possibly replacing them as required.  The common misconception is that filters are a universal solution to maintain the cleanliness of oils and fluids.  Filters are not intended for the purification of heavily contaminated oil or fluids that may contain particles of metal, sand, small stones and other foreign objects.  Oil, water or air contaminated with such particles will remain contaminated after passing through the filters.  To ensure full system purification, it must be completely rinsed.  Oil and other fluids must be filtered thoroughly through an external filter.  This method however, has certain drawbacks, of which the most important one is the significant time required for external purification.  A good example of a long purification process is a large lifting machine which may take up to 15 hours to complete.

The only way to ensure the reliability and durability of hydraulic motors, pumps and other hydraulic components is efficient filtration (removal ) of solid particles and moisture from hydraulic fluid.  The existing national and international standards define the norms which the fluid must comply with. (16/14 class, ISO 4406)  Absolute filtration fineness is set at 3 microns.

Depending on the specific type of equipment, the purity requirements of the fluid may vary.  The versatility of purification and filtration systems therefore, becomes very important.  Versatile systems allow for operation with different types of fluids and ensure the required purity class regardless of original contamination.

This is just what GlobeCore offers. The GlobeCore UVR vacuum purification plants lighten and purify fluids, remove aromatics from turbine oil, industrial oil, and transformer oil as well as other petrochemical products, e.g. dark diesel fuel, HFO, gas condensate etc.