Slippery slope
15 Jul 2014
It may please the bean counters, but a one-grease-fits-all approach may cost companies dearly in the long term.
You wouldn’t run a car without oil, but when it comes to critical equipment, some plant managers are suffering from costly downtime that might be solved by a dose of the correct lubricant.
Using the wrong product – or even too little of the right product - are common mistakes say industry specialists.
But they are even more concerned about plants that spread the use of a single cheap lubricant across multiple functions.
The successful plants are dedicated to preventative and predictive maintenance
Ahmet Guven
It may please the bean counters, but this one-grease-fits-all approach may cost them dearly in the long term, warns Ahmet Guven, application specialist for hydraulics & circulating oils at Shell Global Solutions.
“There are a lot of mistakes being made in industry because in many cases the choice of lubrication falls to purchasing departments which mainly go with lowest price products,” he says.
Guven says one of his customers endured regular and expensive bearing failures until he finally woke up to the true cost of using cheap lubricant.
Although the cost of purchasing the right lubricant is a fraction of the cost of the maintenance budget, “more often than not, plant manufacturers blame their equipment breakdowns on mechanical and maintenance failures,” says Guven.
“I think it is a matter of vision,” he adds. “The successful plants are dedicated to preventative and predictive maintenance and realise that using appropriate lubrication is part of that.”
Guven says many unnecessary mechanical failures would be solved if maintenance people were trained on the consequences of using the wrong or poor quality lubrication, and the correct methods of storing and using it.
For example, some plant operators may think they are doing the right thing by following equipment manufacturers’ specifications, but Guven says if they fail to take into account the special high temperatures and high load conditions of their specific operations, they are still risking potential failure.
He says developing a lubrication manual can help operators to use the correct products to a specific schedule, along with software to systematise their use.
Schaeffler supplies greases and automatic lubricants for rolling bearing and plain bearing solutions.
“Anywhere that has a bearing needs lubrication,” says Ian Pledger, its field services engineer.
Key causes of bearing failure are either contamination, or using inadequate lubricants, including those that are past their useful life, he says.
“There is a calculation for bearing life and there is also a calculation for the grease life. That will give you an indication of what the lubrication period needs to be, and it essential that this period is preserved. Industry statistics show that a significant proportion of premature failures in rolling bearings are related directly or indirectly to the lubricant used,” he says.
The key causes of these problems are use of unsuitable lubricants (20%), aged lubricants (20%) and lubricant starvation (15%).
“One of the big problems we have is that some people have this attitude of supplier reduction and will try to use the same lubricant for a number of applications,” he says.
“But lubricants must be carefully matched to equipment because the grease service life is carefully calculated on load and speed.”
But with fewer maintenance staff manning many process sites, some forward-thinking plant operators are looking for alternative methods to ensure lubrication schedules are adhered to.
“If they can set up an automatic lubricator with correct grease and discharge period then there is one less thing to worry about,” says Pledger.
One company that is fighting friction on a completely new front is Finnish company, Nanol Technologies.
By creating a stable, nano-thin protective layer of copper ions, the company says its new additive can extend the lifetime of both the lubricants and the components they protect, says Aubrey Burrows, Nanol’s senior advisor.
“Engineering designs are getting smaller and lighter but must generate more power, so the lubrication is exposed to much tougher conditions,” says Burrows.
It has been known for a long time that copper would be a useful lubricant additive for demanding applications such as these, he says, but the particles have a tendency to dissolve and separate under certain conditions.
“What Nanol has done is put the copper into a very stable form so the active particles can do the job”.
Although it is based on many years of research, the technology is just beginning to roll out commercially, says Burrows, after several years of testing in the shipping industry, where it has demonstrated its potential for reducing both consumption and wear on machinery.
“There is a fair amount of scepticism in the lubricant world, and additives are often described as ‘snake oil’ with huge promises and little substance.”
However the unique thing about Nanol, says Burrows, is that it only moves to the area where friction actually occurs.
He adds that the company has addressed the safety concerns often associated with nanotechnology by stabilising the nanoparticles in a colloid, which prevents them from being isolated.
For food processors, the problems of choosing industrial lubricants extend far beyond the simple forces of friction.
Supermarket chains are increasingly demanding their suppliers use food-grade lubricants throughout their process to protect against potential contamination.
To err on the side of safety, food manufacturers are deploying lubricants that are completely non-toxic, flavourless and colourless, says Chris Dyson, product development engineer at industrial lubricant specialist, Rocol.
“We produce our Foodlube ranges for incidental food contact and the Purol products for direct food contact,” he says.
With full audit compliance for major supermarkets, the range is ISO 21469 certified and NSF H1 registered for incidental food contact.
Important considerations for food-grade products are whether or not they contain mineral hydrocarbons, genetically modified ingredients or oils or synthetics derived from nut oils.
An industry database of lubricants lists those that are approved and certified to have no contaminants for use in food processing, says Dyson.
“The general trend in all sectors is for products with lower toxicity, health hazard, and environmental impact. That informs our development,” he says.
“However, one of our big challenges is to remove chemicals with a poor toxicity profile and replace them with something that will perform even better without the environmental or health impact.
“A lot of food manufacturers are audited by their customers to make sure they are keeping on top of standards. This is not just about ensuring low toxic lubricants are used, but that the processes are right,” he says.
“For this reason, we ensure all of our aerosol packaging is metal detectable, so if anything drops in it should get picked up in the process.”
Tech talk
Lubrication is evolving fast as the industry moves away from simple mineral oils and soaps to synthetic products designed for highly specialised uses. Technology that can help to automate or schedule lubrication is also being increasingly deployed, along with systems that use condition monitoring techniques to ascertain lubricant and machine health.
Oil monitoring
When it comes to preventative maintenance, oil analysis can be effectively combined with vibration monitoring to provide early warnings to plant operators, says Steve Lacey, engineering manager at Schaeffler. It is “critical that any systems set up to monitor the condition of a machine are also capable of monitoring the condition of the lubricant,” he adds. Schaeffler’s FAG Wear Debris Check oil monitoring system works alongside other condition monitoring systems to indicate damage or wear to bearings, cages and gears within a gearbox or other industrial gear unit. The oil monitor works by utilising an inductive particle counter which is able to distinguish between ferrous and non-ferrous metal particles present in the lubricating oil. The sensor operates on the principle that any wear to a component will result in small metal particles being rubbed off into the oil, often several months prior to an actual failure. Shell also supplies an industrial early warning monitoring system called LubeAnalyst for monitoring the condition of their machinery and lubricants to identify potential oil or equipment failures before they become critical.
Synthetics
As the drive to reduce environment impact intersects with the need for increasing efficiency in plant equipment, synthetics and other additives are being developed to replace contaminants such as metal, sulphur, zinc and phosphorous. Ahmet Guven, a hydraulics & circulating oils specialist at Shell Global Solutions, says: “We need to meet the requirements of high speeds, high loads, anti-oxidant properties, and smaller spaces. “Moving from mineral oils to synthetics is an important way of increasing reliability.” An example is Shell’s Tellus range, which includes long-life synthetic technologies for demanding applications.
Automation
Automatic lubrication devices ensure a constant supply of lubrication without the need for manual intervention, especially in mission critical or difficult-to-access areas. Schaeffler recently announced a multi-point lubricator called Fag Concept8 for rolling bearings that can be adjusted to provide four different lubrication volumes to cater for bearings with varying lubrication requirements. The system can dispense lubricant to rolling bearings in a wide range of industrial applications, including pumps, fans, compressors, gearboxes, electric motors, and production lines in food and drink processing plants.