Lubricants: Key to plant efficiency

Industrial lubricants and greases play a key part in keeping plant and machinery in good working order. Sandra Calic, global direct sector marketing manager for general manufacturing at Shell, looks at best practice in plant lubrication and explains the science behind the latest 'synthetic' lubricants

Plant engineers are under more pressure than ever to ensure capital equipment is kept in optimum working condition for a productive and cost-effective operation. Much of the time, lubricants are an afterthought - understood as a necessary part of day-to-day working, but not always seen as a vital component: Ensuring correct lubrication use can help generate cost savings by minimising downtime and enhancing machinery protection, particularly in environments where optimum productivity is critical for delivering against peaks in demand.

The role of a lubricating oil is to provide the optimum protection to the equipment and other moving parts. This involves reducing friction and protecting against acids, deposits, and wear throughout a range of operating conditions. By opting for lubricants that offer enhanced levels of protection and mitigate other operating factors such as fluctuations in temperature, plant engineers can help ensure that their machines are not only working to optimal service levels, but that they are safeguarded against premature wear and tear, and unnecessary maintenance downtime.

Synthetic technology Today, in many situations, synthetic lubricants can be the highest performing lubricants and are based on man-made technologies that offer a range of benefits - enhanced protection, and thus greater durability of equipment, and longer oil life through reduced deposits and oxidation, which help contribute to improvements in efficiency, downtime and maintenance costs.

Alongside this, they can be manipulated to maintain protection in harsh environments, such as where machinery experiences dramatic temperature fluctuations, or may be submerged in water.

Synthetic lubricants start with 'high grade' synthetic base oils. Traditionally, lubricants have been based on mineral oil, a component of whole crude oil. Thanks to modern refining technology, today's highquality mineral oils provide adequate protection. However mineral base oils are complex mixtures of naturally occurring hydrocarbons and may contain impurities.

On the other hand, synthetic base oils have been chemically altered to reduce impurities and are engineered - using specialist additives - for excellent low-temperature flow properties, high resistance to thermal degradation and low oil consumption.

Depending on the product, additives can account for 1 to 30% of the lubricant and achieving the right blend is what sets a quality lubricant apart from its competitors.

Synthetic lubricants have been proven to deliver extended life cycles without impacting upon quality or performance; in some cases lasting up to two or three times longer than they did a decade ago. This means that engineers do not have to contend with replenishing oil levels as frequently, reducing costs and time spent on upkeep.

Lubricant selection Recognising the importance of correct lubrication choice and application is one thing but many companies lack the time needed to keep up with the latest products and technologies. There is help available, and engineers or those who purchase, should take advantage of the expertise available from their supplier. For example, Shell LubeMatch is an online service which helps to identify appropriate lubricants for each individual operation. Services such as Shell LubeAdvisor work alongside online tools providing help through highly-trained staff.

Application In operational environments the use of synthetic lubricants, compared to nonsynthetics, has demonstrated cost and time savings for many plant and manufacturing operations. Reported savings, from extensive field trials, as well as directly from customers, reinforce the benefits to be had from using synthetic lubricants. For example, a plastics plant in Turkey, Wavin Pilsa, which was dissatisfied with the poor performance of its compressor lubricant, used Shell support services to help identify a suitable oil for its operation. Oil sample analysis indicated the oil it was using had poor thermal and oxidation stability, which resulted in the need for an oil drain every 5000h. As a consequence, operating and maintenance costs were higher than they needed to be.

The Shell Lubricants technical team recommended a change to Shell Corena S4 R 68, an advanced synthetic air compressor oil incorporating a high performance additive system. The product is designed to deliver high performance lubrication of rotary sliding vane and screw air compressors. It uses an advanced additive system to provide enhanced protection and performance for compressors running at pressures over 25 bar and in excess of 100°C discharge temperature with oil maintenance intervals to 12,000h.

The switch reduced costs by 50% and increased the oil-drain intervals from 5000 to 10,000h. The company reports saving US$12,185 a year, resulting from lower oil consumption and labour costs, less oil waste for disposal and improved maintenance.

Ongoing care Lubricants are a relatively small part of total operating expenditures, yet they can add incredible value to the working life of a plant, so ensuring they are monitored regularly and stored adequately can lead to further cost savings and efficiencies.

Lubricant servicing should be considered a standard procedure in the ongoing care of an oil and the machine components it is protecting. Such checks can mean avoiding unnecessary oil changes; the technology is designed to identify potential oil or component failures before they become critical, but allows engineers to rest assured that until that time, the oil will work to optimal levels.

For example, Shell LubeAnalyst is an oil and equipment condition monitoring service that involves taking samples direct from working equipment. These are analysed and tested in an accredited laboratory.

Test results are provided along with a diagnosis and, if necessary, recommendations for adapting oil use to resolve any problem areas.