March 2019

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Maintenance: Mind the small stuff—Tips to manage particle contamination

Particle contamination in lubricants is the primary cause of lubricant-related equipment failure and hydraulic system failure, according to industry studies.

Goldman, T., Sun Coast Resources, Inc.

Particle contamination in lubricants is the primary cause of lubricant-related equipment failure and hydraulic system failure, according to industry studies. A 300-gal hydraulic reservoir can contain up to 8 g of particle contamination. Most particles are too miniscule for the naked eye to see, yet are the perfect size to cause abrasive wear and disrupt operations.

However, a faulty, long-held, industry-wide belief remains that using clean fluids leads to clean machinery. While partly true, this practice alone will take decades to realize benefits if equipment is not first cleaned. To reduce particle contamination, improve fluid cleanliness and maximize equipment life expectancy, the better approach is to remove the debris in the equipment before new clean lubricants are introduced.

There is no better time to remove debris and manage contamination than when equipment is shut down during scheduled maintenance or a turnaround. Simple steps to reduce contamination and increase the life expectancy of equipment by as much as seven times are discussed here.

Find your bearings

A thorough analysis of fluids should be conducted to establish a baseline and identify areas of contamination. Fluid samples of critical equipment are taken in advance of a scheduled turnaround or maintenance event to measure water contamination, microscopic particulate contamination and even insoluble varnish-forming precursors. Technicians typically work closely with third-party analytical laboratories to independently verify the results.

FIG. 1. Since normal operations can create significant amounts of dirt, it is critical to remove storage tank contaminants. Turnarounds and scheduled maintenance are the best times to conduct these operations.
FIG. 1. Since normal operations can create significant amounts of dirt, it is critical to remove storage tank contaminants. Turnarounds and scheduled maintenance are the best times to conduct these operations.

The tests provide plants with a results-based schedule, rather than a time-based schedule that identifies the equipment with the most contamination. This schedule saves time and money, which is crucial during a turnaround.

Results rarely come back without finding areas of contamination (i.e., dirt, water, metal, silicate, paint and water) because contamination inevitably happens along the lubricant’s journey from the manufacturing plant to the equipment system or storage tank.

Particle size and composition are measured to determine a fluid’s contamination levels. As particles move through the equipment’s system, smaller pieces result and work into the machines to cause abrasion, adhesion, fatigue, erosion and wear. The most common detriment is abrasive wear caused by clearance-sized particles interacting with two sliding surfaces.

Clean tanks

Turnarounds and scheduled maintenance are the best times to clean tanks and flush lines because the equipment is down.

It is critical to remove storage tank contaminants because normal operations can create significant amounts of dirt (FIG. 1). If possible, personnel should physically enter the tank to clean it. If this is infeasible because the tank is too small or too difficult to reach, then it should be steam cleaned with a tool snaked into the container. The overall goal is to restore the inside of the tank to the same clean state as before the fluid entered.

An appropriate analogy is that equipment and fluids are like mud and ice cream. If ice cream is dropped in the mud, nothing happens to the mud, yet the ice cream is ruined. If the equipment is not clean, then the fluid is quickly spoiled.

Filters 101

It is easy to ignore filters, but they play a critical role. Unchanged filters wreak havoc on equipment because particles will eventually bypass the filtration system and damage equipment. This is a costly oversight, especially if production is halted for days to repair the equipment. Filtration maintenance must be preserved with a monthly or quarterly program to reduce the level of contaminants over time.

The plant’s control room typically monitors both lube oil and breather filters on storage tanks, so plants can act fast once a filtration issue arises.

Certified clean fluids

When tanks are clean and filters are ready, it is time to use a certified clean fluid to maintain the system’s cleanliness, maximize the life of the equipment, meet stringent quality control standards set by original equipment manufacturers (OEMs), decrease unscheduled downtime at the plant and save money. It costs 90% less to remove particle contamination before fluids are introduced into the system than to remove particle contamination after the fluid enters the machinery.

Certified lubricants also reduce the expense and time required by end users to prefilter non-certified lubricants to meet stringent OEM-specified International Organization for Standardization (ISO) cleanliness recommendations. Certified fluid is rigorously tested and verified before each customer delivery.

Schedule ongoing analysis

After a turnaround or scheduled maintenance, monitor fluid cleanliness with regular fluid analysis to assess the particle count of fluids present, and identify any contamination that requires action.

Personnel at plants located on the Texas Gulf Coast should remember that water is the primary contaminate and does the most damage to equipment. Just a 0.05% increase in water contamination reduces the expected life of a bearing by 60%. Unfortunately, 0.05% is too little to detect visually, so unique instruments are needed to identify water in parts per million (ppm). It is important to work with a supplier with the ability to perform such testing and consulting.

Takeaway

Most plant equipment is mission-critical; few non-critical or redundant pieces of equipment exist. To protect these assets, operators must conduct a thorough fluid analysis to establish a baseline, clean tanks regularly, keep up with filtration maintenance, use certified clean fluids and do regular check-ins to pull samples and track progress.

A contamination management program not only improves fluid cleanliness, but can also maximize the life of the equipment and contribute to cost-containment goals. For a plant, an effective program translates to better maintenance, less downtime, higher productivity and more responsible stewardship of capital expense. HP

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