Nov 14 2019
An interview with Matthew Harle, Senior Manager, Field Marketing Particle and Automation, Beckman Coulter
Please give an overview of contamination in industrial fluids and how contamination in fluids causes catastrophic failures for example hydraulic failures.
The industry standard is that 70 to 80% of hydraulic failures are directly attributed to contamination and there are various different types of contamination. Those failures can happen in different ways, for example a complete system failure, a component failure or a component blockage, or you could simply lose efficiency because of contamination. That's why contamination control is so important in hydraulic systems.
There's a very good video by Caterpillar that shows that loss of efficiency is not recognized until you see 20% loss in productivity, the equivalent of losing a day a week. The loss of efficiency and actual usability of the equipment is caused by contamination directly.
Fluid Contamination | "The Silent Thief"
Contaminants that we look for can be categorized as hard and soft particles which are invisible to the naked eye. The naked eye can typically see about 40 microns across and these contaminants are around 4 microns, meaning that workers simply can't look at a sample of oil and say whether it’s contaminated or not.
Hard particles are contaminants such as metallic particles, dirt or sand. For example if you're working out in the desert, sand is a big issue.
Soft particles are contaminants such as water and air, which all cause loss of efficiency and damage the hydraulic system.
There are other sources of contamination in hydraulic systems including bacterial growth, which can occur if you have free water in your system. However, what we're looking for with a particle counter are hard and soft particles.
Wherever there are hydraulics there will be contamination of one type of another, at one level or another. How much depends on how the hydraulic system is cared for.
A service technician repairs a damaged hydraulic pump. Professional power hydraulics workshop. Hydraulic motor folding. Image Credits: slaved | Shutterstock
Even by adding new fluid to a hydraulic system, if that fluid has not been appropriately filtered then just because it's new doesn't mean it's clean. The reality is that it's not clean because when it's made is not filtered to the levels that are required for a hydraulic system.
Another major factor is that customers often don’t know that they have contamination in their hydraulic fluid simply because they haven't analyzed their fluid.
In some cases, the criteria for contamination from our customers is whether the machine is still working. For example, I’ve seen a cement mixer with a hydraulic tank and a sight tube on the side displaying the level of the hydraulic fluid. In this particular sight tube, you could see that half of the content was water, but as far as they were concerned, they didn't have a problem because it hadn't broken down.
However, the reality was they did have a problem because their machine was operating at a far lower efficiency than it should have done, and they were going to have big issues at some point in the not-too-distant future.
How are industrial fluids kept clean in industry, especially where there are numerous types of potential contaminant?
Filtration is the primary method of contamination removal and there are many different types of filter. For example for water contamination, there are water absorbing filters, or a vacuum dehydration system can be used to remove water from hydraulics.
Every filter has a gauge built into it that shows how contaminated that filter is, which is measured by differential pressure. When the differential pressure has exceeded a certain limit, the filter is changed.
This is fine unless the filter gets a hole in it, which will stop the differential pressure exceeding the predetermined limit. This may suggest to the user that their fluid is nice and clean, and therefore their system is also nice and clean. This is why it’s also important to perform analyses of the fluid to make sure that they don't have contamination.
How are industrial machines monitored and industrial liquids tested to ensure that they are clean?
Let's take a gas turbine as an example. The most common method of monitoring the condition of the turbine is using vibration sensors. Once the system is setup, changes in vibration are monitored. When an increase in vibration is noticed, it is then assumed that something's going wrong, something is out of alignment and this will be investigated.
However, particle counting on lubrication systems will give an indication long before vibration monitoring, as a rapid increase in particle count will be seen before any damage occurs.
Another method of monitoring industrial liquids is to perform oil analysis by sending oil samples to a laboratory on site or to a third party. This includes a range of parameters including the total acid number, the water content and variance in viscosity.
The third method is to carry out your own particle count, either through sending samples to a lab, doing it yourself with a portable device, or with online monitoring.
The argument for oil analysis is quite strong, oil analysis definitely needs to be carried out one way or the other. However there are three issues with this, first they are relatively expensive for the work that is done, second it takes time to get the results, which can vary depending upon where you are, for example in Europe the wait isn’t not too bad, however if you're in Africa, for example, it can be two weeks or longer before the results return.
The third issue is that very often, there's nothing wrong, which means that a full laboratory fluid analysis is conducted when in fact, a particle count with a particle counter on site would have demonstrated the same result, and were there any issues with the fluid, these would have been detected by an increase in the particle count levels.
As soon as there is an increase in particle count, that's the time when you should be sending samples for an in-depth analysis, however, because customers aren’t completing particle counts before requesting full analyses of their industrial fluids there is quite a lot of money being wasted.
On the other hand, customers may not want to buy a particle counter because that's often counted as an investment that will need to be justified. However, using a particle counter will significantly reduce the number of, and therefore the overall cost of, full oil analyses.
What does Beckman Coulter offer to monitor contamination in industrial fluids?
The HIAC, or HIgh ACcuracy, range offered by Beckman Coulter Life Sciences, was originally produced by the inventor of liquid particle counters in the late 1960s by Dr. Leon Carver. He invented the light extinction method that is built into all our instruments. It’s evolved through time from light bulbs and photomultiplier tubes to using laser beams and photodiodes. The essential principle is still the same and this is the ISO standard method particle detection for this industry.
Beckman Coulter Life Sciences offer various different types of particle counters. Laboratory particle counters, that are placed in the central laboratory and allow customers to bring bottled samples to that analyzer to perform particle counts. Portable particle counters, that will allow customers to sample both bottle samples and online on site, and also online monitors that connect directly into the hydraulic system.
Beckman Coulter HIAC 8011+ Laboratory Liquid Particle Counter. Image credit: Beckman Coulter
HIAC PODS+ Liquid Particle Counter. Image credit: Beckman Coulter
In my view online particle measurements are the best way of particle counting. This method removes any possibility of contamination that can occur when taking a bottle sample, which is important because the particle size that we're looking at is really small.
If you take a sample with a bottle you may get contamination from the environment, which will affect the results that you get. With online analysis, typically, customers see that their oil is a couple of ISO classes cleaner than it would be compared to a bottled sample.
Online monitors are fitted into the hydraulic system of an instrument and provide results 24 hours a day 7 days a week. They are trend monitors, when you see a change in the trend that's the point at which you start investigating sources of contamination.
We provide the equipment that allows the customer to carry out particle counts on their fluid and ensure that their fluid is clean. When an increase in the particle count is seen, that's the point at which customers should then complete an in-depth analysis to find out what those particles are and where they're coming from within the hydraulic system.
What are the advantages and limitations of online particle counting? What case studies are there showing the advantages and limitations?
As good example of this, a paper mill in Sweden a few years ago had an issue with a bearing that kept failing with no known cause. This bearing cost 60,000 Euros at the time, and there was a very long lead time, so the mill had to keep one in stock. This resulted in wasted inventory sitting in a warehouse just in case they needed one.
This paper mill put a particle monitor on the return line of the lubrication system for this particular bearing and discovered that they were getting an increase in particle count at certain times.
When they investigated further, they discovered that this was happening during the clean down of the paper mill, and that part of cleaning process was to spray the bearing down with a jet wash, which was introducing water into the lubrication system. This was causing the bearing to fail and was picked up immediately by the online particle counter making it easy to change their processes and save many thousands of Euros.
In an ideal world every customer would have an online particle counter on their hydraulic system and multiple sensors around a system to monitor it, in the same way as vibration sensors for vibration monitoring. However, the reason that this isn’t common is the cost. At Beckman Coulter Life Sciences, we tried to make a particle monitor that would compete pricewise with vibration analysis, and it simply couldn’t be done. However, it is the superior method of monitoring for contamination.
The main limitation with particle counting in general is that it doesn't tell you what the particles are. It just tells you you've got an increase in particle count, usually that's all that’s needed, a change in particle count level.
However, this isn’t useful for all systems. For example air bubbles are also counted as particles. In most cases you want to know about this, but in some cases air is an accepted part of the system, for example the splash gearboxes in wind turbines have highly aerated oil, which means that online particle counting isn’t an option. Instead oil samples need to be taken off site, degassed and analyzed by laboratory particle analyzers.
One particular limitation with our online monitor is that it has no memory. It will need a means of collecting that data, such as a computer or PLC.
How is reproducibility maintained between testing? How are the fluid testers cleaned and maintained to stop contamination?
To reduce and remove contamination between samples you simply flush with the fluid that you're about to sample, which removes any of the previous sample before the next analysis. The particle counter can also be set up to discard the first sample it takes in any analysis, which acts in the same way as a flush.
The instrument can also be manually cleaned with the built-in cleaning routines in both the portable and lab particle counters that use automated flushing routines.
I think we produce the only particle counter that has these automated routines built in. These work with a simple one button push and then the user can walk away to leave it to finish the routine.
What application areas does Beckman Coulter serve in the hydraulic fluid space? Which liquids can be tested with the Beckman Coulter range?
The applications are very wide ranging, including mobile machinery, paper mills, steel works, offshore industries, mining, military, aircraft, and really anyone who's using hydraulics or hydraulic equipment.
Offshore industries for example use significant amounts of hydraulics under the sea, that all need proper cleanliness because they can’t afford to have failures.
Beckman Coulter Life Science particle counters can analyze most fluids, including hydraulic fluids, phosphate esters and water based fluids, water glycols and diesel. The main consideration is around compatibility of the seals and sapphire cell the instrument. There are very few fluids that we cannot analyze.
What is the future of industrial fluid testing? What is the future for the Beckman Coulter range?
The future of industrial fluid testing is moving away from reactive maintenance regimes and towards proactive and predictive maintenance regimes. Being proactive about maintenance is a complete change in mindset for most people, but while there is an initial cost there are usually significant cost savings in the long run.
By being proactive you can get to the point that predicts any faults in the system, which allows action to be taken to prevent hydraulic systems breaking down.
There is no doubt particle counting will be a key tool in that predictive system.
In terms of the particle counters that Beckman Coulter produces, I would like to see more functionality added to them, instead of only counting particles, perhaps viscosity, moisture sensing and other parameters could be measured. One of our portable instruments already has the option for moisture sensor but I’d like to see it as standard.
The ideal solution would be to get to the point where we have a condition sensor that tells you what about the condition of the fluid being tested overall. At the moment we're still a while away from that, but it’s something that is being moved towards.
Where can readers find more information?
About Matthew Harle
Matt Harle is the Senior Field Marketing Manager for the Middle East, Turkey and Africa regions for Beckman Coulter Life Sciences, and also works with the teams in India and Russia. He is based in the UK, and has been at Beckman Coulter since 2010. He has worked in the fluid power industry since 2001, when he was the European fluid power manager for Hach Ultra Analytics. Matt introduced the HIAC PM4000 particle monitor, the first particle monitor on the market, to Europe and the UK. From 2008 – 2010 he worked for Argo-Hytos as a sales engineer in their condition monitoring division. In 2010 he rejoined Hach-Lange as the fluid power manager for Europe, and remains the regional subject matter expert for particle counting in hydraulic fluids. Matt has previously sat on the ISO/TC131 committee as part of the British Fluid Power Association.
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