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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.

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.

Flushing of Hydraulic Systems Found in Industrial Equipment and Mobile Machinery

Hydraulic System Contamination

In accordance with widely accepted industrial standards, preventive maintenance processes that remove contaminates from hydraulic systems can produce the following benefits and results:

  1. The effective Service Life of hydraulic motors, pumps, valves and distribution devices can be doubled.
  2. Hydraulic system warranties can be extended by as much as two years due to the reduction in the risk of hydraulic system component failure during the warranty period.  Fluid purity however, must still be monitored and controlled and the hydraulic system must be cleaned annually.
  3. Equipment downtime is reduced.
  4. The cost of transportation of equipment to repair facilities is reduced or eliminated.

Even if oil and hydraulic filters are changed completely, it still does not guarantee that the hydraulic system will be completely free of contaminants.  Solid particulate matter, can and will, remain in valves, pumps, motors and on the internal surfaces of high pressure hoses.  By introducing certain changes that greatly improve filtration system efficiency, equipment downtime can be significantly reduced because the fluid is purified and contaminates can be removed much more effectively than by a simple oil and filter change.

Studies and practical experience indicate that over 70% of hydraulic system failures occur within the hydraulic drive.  In turn, 50% of the hydraulic drive failures occur due to the presence of solid particles in the hydraulic fluid circulating in the system and the drive.  The high percentage of drive failures is due to the fact that hydraulic drive components rapidly wear down when operating with contaminated liquid.  This leads to a reduction of operating efficiency and an increase of internal energy loss.  Operational costs also rise all due to a lack of timely preventive maintenance.

If Serial Filters are used in the hydraulic system, the concentration of solids in the fluid will be approximately 0.022% by weight.  This is 4.4 times above the acceptable standard.  Particles from 10 to 40 micron in size can constitute up to 50% of the contaminants in the fluid.  These sizes mostly coincide with the clearances between friction surfaces and are therefore, the most dangerous and cause the most wear.

As with serial filters, Main Line Filters also cannot provide the required level of hydraulic fluid purification needed to prevent systems failures by themselves.   The hydraulic drive therefore, must be rinsed by special means or processes.

The importance of a thorough cleaning of the hydraulic drives is because of the high level of precision components found in hydraulic systems that are very sensitive to even small amounts of contamination.  As the system becomes larger, the rate of contamination also becomes larger increasing the need for timely preventive maintenance.

If the equipment is operated in dusty environments, particles of dust will settle on cylinder shafts and will enter the hydraulic drive.  A large portion of contaminates and wear products enter the hydraulic tank through the drain lines and cylinder shafts thereby avoiding the filter system.

A excellent way to improve and maintain the purity of hydraulic fluid is through periodic rinsing and removal of harmful particles.  GlobeCore’s UVR Purification Units are specially designed systems aimed at purification of turbine oil, industrial oil, and transformer oil and have a reputation for versatility and reliability.  They have the ability to purify oils and fluids back to their original new like condition and can even exceed well established quality standards.  The UVR plants, due to their compact design and high level of mobility, can be used at your maintenance facility or offsite at remote locations.  There are no restrictions that limit the use of the UVR systems anywhere there is a need for oil purification services.  The compact design allows GlobeCore to ship the UVR units to anywhere in the world.

While cleaning the system, it should be noted that special detergents can only be used in the beginning stages of the process since any detergent remaining is considered an unwanted contaminant.

Prevention of Contamination

Prevention of hydraulic system failures is only possible if enough attention is paid to the most likely cause of the failures.  It is generally accepted that contaminants are the leading cause of system failures. It is therefore, important to use effective methods of controlling and preventing contamination.  Controlling contamination can help to ensure efficient operation of the system, extend the service life of components, and eliminate malfunctions before costly repairs or unplanned down time is required.


A daily testing of the hydraulic system allows the operator to quickly localize leaks and other malfunctions before they impact operation.  Periodic checks include checking the pressure in the system, visual inspections, and checking fluid level before, during and after the completion of the work cycle.

Inside the Hydraulic System

Prevention of contamination is very important, but it is equally as important to understand the processes occurring inside the hydraulic system. Regular checking of hydraulic fluid is the best way of localizing part wear and contamination.

Regular sampling

In order to precisely estimate the condition of the hydraulic system, regular sampling of the fluid is required and recommended as part of a comprehensive preventive maintenance program.  It is recommended to take an oil sample for analysis every 500 hours of operation or sooner if the equipment is operated in extreme conditions.  If samples are taken regularly, a certain base line may be established and will allow the operator and maintenance manager to immediately see any deviations allowing for timely corrective action.

Tests and Trials: Sport, Art or Industry? Analysis of Transformer Oil Purification

The correct use of oil guarantees the reliability of industrial equipment and the prevention of equipment failures.  Transformer oil is a dielectric insulator and a coolant.  It also serves as an arc extinguisher preventing shorts and internal fires.

Transformer oil parameters degrade over time as the oil ages.  Oil oxidation is mostly caused by external elements such as water, air, acids and heat.  Aging of oil is best indicated by its acidity level, water content, and sediment and sludge formation.

Sludge accumulates in the solid insulation, the core, in cooling channels and other places inside the transformer.  Sludge is a dangerous enemy that degrades the oil’s cooling and heat transfer capabilities and damages the solid insulation causing it to disintegrate.  A short-circuit in the transformer windings becomes a much higher possibility due to oil degradation and sludge build up.

The acid level of the oil, as measured by the “Acid Number is the main indication of oil degradation and oil aging.  Acidity is measured by special litmus paper that changes color when subjected to contaminants.  Acids can damage cellulose insulation and metal parts of the transformer.  Acid levels can also measured through an oil analysis program.

The Acid number, as the main indication of transformer oil quality, is the amount of grams of KOH required to neutralize all free acids in one gram of oil.  The Acid number indicates how much the oil has aged and whether it should be regenerated using the GlobeCore Process.  Once the Acid number reaches 0.08 and higher, the transformer oil becomes aggressive and begins to destroy the solid insulation of the transformer.  The Acid number therefore, is the best indicator of when to service your transformer before irreversible damage is done to the insulating paper.

Besides chemical parameters, transformer oil must comply with certain physical and electric parameters.  Degradation of these important oil qualities may indicate problems inside your power equipment.

For instance, the oil’s flashpoint must be high enough to ensure fire safety in overload conditions and high temperature increases inside the transformer.

Dielectric strength of transformer oil is important for the prevention of breakthroughs in the transformer insulation.  This parameter is measured regularly by high voltage breakthrough indicators.  Transformer oil is tested six times with 10 minute intervals between each test.  The average of six tests is used to determine the dielectric strength.  If the results are unsatisfactory, another sample is tested and a decision on the course of action is made.

Fresh or used transformer oil must be tested before being placed into the transformer.  Some parameters tested are particulate matter content, general oxidation stability, transparency, dissipation factor, flash and setting points, viscosity, acidity and water content.

These measures are designed to identify and resolve problems before the they can cause a transformer failure shutting down the transformer.

Transformer oil is purified of contaminants, acids and gases in purification and regeneration equipment specifically designed for transformer maintenance.  Complete preventive maintenance systems, such as the GlobeCore CMM-R line of equipment will reduce costs and downtime while increasing operating profits.