Combatting Contamination

According to Stephanie Schaffer, Director of Product Management at Des-Case Corp., the two primary types of contamination are dirt and water. Dust, dirt, debris and moisture are present in virtually every industrial environment, said Schaffer, who is based in Goodlettsville, Tennessee, United States, and who joined Bernard in his presentation. If the atmosphere is contaminated, the oil is probably dirty, and lubricant quality is compromised.

Particulate contamination, once inside an operating system, accelerates the generation of new contaminants, which damage critical components and act as a catalyst for oxidation, further degrading the oil. If the atmosphere is particularly humid or has frequent temperature fluctuations, the oil is probably moisture laden, and lubricant quality is compromised, said Bernard.

Often, plant wash-down activities are responsible for inducing conditions that cause moisture ingression into the lubricant system. The added moisture can lead to corrosion in critical components.

These factors can be effectively controlled with some preventative maintenance techniques, Bernard said. A multifaceted program that includes some simple proactive steps will conquer contamination. He noted that a variety of websites, publications and manufacturers offer training materials that can get you well on your way.

Todays options for restricting the ingression of contaminants are far superior to yesterdays open tube turndown pipes that did little more than keep the birds out, Schaffer said. Proper installation and maintenance of reservoir breathers can significantly reduce ingression of airborne contaminants.

Conventional vent ports or breather caps provide little or no protection, said Bernard. They are typically rated at 40 microns and offer no means of capturing moisture. Retrofitting these ports with breathers will provide continuous protection against both dirt and water.

Breathing starts the day a machine is put into operation or a tank is filled. The best approach to preventing dirt and moisture damage is to proactively control ingression points, said Schaffer. Since the most common point of entry is the conventional vent port, installation of desiccant breathers is imperative. She added that combining breathers with other contamination controls, such as mechanical seals, proper sampling techniques, downstream filters and appropriate lubricant storage and dispensing will increase the chances of meeting or even exceeding life expectancies.

Schaffer then explained that the effectiveness of breathers depends on a number of factors, including temperature variations, environmental conditions and operating parameters. Tests show that a desiccant breather can reduce relative humidity in the equipment headspace to as low as 10 percent and keep oil particulate levels near their original levels.

Ins and Outs of Filters

In-line and off-line filtration (sometimes called bypass, kidney-loop or auxiliary filtration) consist of a motor, pump, filters and proper hardware connections. Fluid is continuously pumped out of the reservoir, through the filter(s), and back to the reservoir. In-line is, of course, a permanent part of the overall system. An off-line filtration loop has the advantage of being relatively easy to retrofit on an existing system that has insufficient filtration. Also, off-line filtration devices can be serviced without turning off the main system.

Off-line filtrations systems can be mounted on portable hand carts that make it easier to shift the system from one machine to another. These can be the same type of carts used to transfer lubricants from storage areas to the machines where they are used. Filter carts should be used to remove particles and moisture, thereby preserving the working life of the oil, Bernard explained. To avoid cross-contamination of fluids, he said, make sure there is a dedicated filter cart for each type of lubricant in use. Filter carts should be fitted with quick disconnects and with particle-removal and water-absorbing filter elements.

Using filter carts can be part of a routine that includes new oil filtering, transferring, and dispensing oils. Many plant personnel feel new oil is clean enough to use right away, said Schaffer. New oil isnt necessarily clean. As storage containers and machinery expand and contract, dirt, moisture, dust and other contaminates ingress through the OEM vent cap. Research shows that keeping lubricants clean and dry extends equipment life by one and a half to three times. Fluids should always be filtered before being put into service.

Making Choices

Numerous filter units are available from different vendors, and the options on them vary greatly. Bernard and Schaffer said plant operators should consider some basic questions before selecting one.

The first question, they said, is where the filtration is needed. This will influence whether you want to look at a fixed unit, a traditional cart on wheels or some of the newer, more compact units, Bernard said.

The second question is, what machines and fluids are being filtered?

Bernard said the answer will affect a number of things. For example, it will impact the number of units needed to reduce cross contamination. In addition, it will help guide the choice of filter including media, micron rating, water removal properties, etc. The final factor to consider is the material of construction of the filtering apparatus.

Finally, how often is filtration needed? If you have an application that needs filtration for the first time, a general rule is to filter the oil through seven passes to ensure that nearly all of the oil in the reservoir has been adequately cleaned, said Schaffer. However, if the oil can be completely removed from the system, one or two passes should suffice.

After initial cleaning, consider the criticality of the application, its sensitivity to contaminants, and the ingression rate of contaminants (through seals, from the environment and internal abrasiveness) in setting the filtration schedule.

Savings Are Everywhere

Schaffer and Bernard listed a number of areas to consider to ensure that oil is kept clean. The first area was storage. Bernard pointed out that many improvements to storage procedures can be made with minimal cost. A little time spent simply reviewing current storage and handling procedures can be informative and useful. Some simple procedures to improve storage maintenance operations include keeping stored oil indoors and adding breathers to vented storage containers.

Temperature control also is important for proper drum storage. Drums breathe as internal pressure rises and falls with temperature variations. Moisture and other contaminants can be forced into the drum when the internal pressure drops. Therefore, said Bernard, Store drums or containers in enclosed, temperature-controlled facilities.

Shielding storage containers from dirt and moisture is another procedure that will keep clean and filtered oil in good condition. Be as careful with pumps and transfer containers as with storage containers, added Schaffer. This will minimize the chances of cross-contamination with other lubricants and introducing contaminants into machines when filling.

Handling is the second area to check, said Schaffer. First, transfer hoses should be equipped with quick connects to prevent contamination from entering, provide leak-free connections to tanks and reservoirs and allow a method for off-line filtration.

Second, oil-dispensing equipment – including tanks, drums, pails, hoses and reels – should be clearly labeled to avoid cross contamination. Color-coding is helpful in avoiding cross contamination. Finally, an industrial filter cart can be an economical way to protect a system from contamination.

The third area cited by Schaffer and Bernard was equipment. Nearly every industrial application is a candidate for a contamination control solution, Schaffer said. Gearboxes, pumps, turbines, transformers, hydraulic systems can all be looked at as opportunities to save money through reduced downtime, increased oil life, decreased oil replacement and disposal costs, and increased machinery life and reliability. Examining seals, ensuring the application has the correct size breather and regular filtration of oil can extend oil life significantly, saving tens if not hundreds of thousands of dollars, Bernard said.

The Payoff

Contamination control provides the single greatest opportunity for gains in the average lube program, said Bernard. A programs effectiveness can be measured through the following metrics:

maintaining targeted ISO cleanliness codes;

reduced moisture levels;

extended lubricant life and drain intervals;

longer periods between failures;

less unscheduled downtime;

and cost savings such as less component repairs, decreased oil disposal expense and decreased oil purchases per machine or part produced

There is an inverse relationship between lubrication quality and maintenance costs. Financial gains can be made by implementing procedures that maximize lubrication effectiveness. Bernard concluded by saying that implementing contamination control techniques to maintain clean, dry lubricants – and gaining the profitability that goes along with it – is easier than ever.