Reducing the Effects of Contamination in Hydraulic Systems
Contamination can be introduced into hydraulic systems from a variety of sources. It is impossible to remove all potential contaminants from a hydraulic system. Rather, the focus of operators, maintenance technicians, and others responsible for the daily use, maintenance, and repair of such systems is to develop solutions to reduce the number of contaminants as best as possible.
Effects of Contamination
Failing to implement the right preventative measures will almost certainly result in system failure due to contaminated hydraulic fluid. The results of contamination are:
- Reduced System Performance
- Pump & Motor failure
- Greater Strain on Valves, Parts, and Components
- Reduced Control over Flow and Pressure
- Higher Levels of Heat Generated
- Sticking of Parts
- Seizing of Parts
Most contaminants are found in the hydraulic fluid and slowly affect other parts of the system. Solid particles can start to form an abrasive sludge that damages all system components. Particles suspended in the fluid affect the velocity of the fluid and result in reduced lubrication, causing further contaminant.
Water can also cause corrosion. In more extreme cases, larger solid particles can block openings in different areas of the system, restricting the flow of fluid and causing overheating and system failure.
Sources of Contaminants
There are all sorts of different contaminants that can be introduced into hydraulic fluid and systems, and these include both exterior and interior sources, as follows:
- Airborne Particles – Dust, dirt, and water vapor can be drawn into the system and contaminate the fluid.
- Changes in Temperatures – Moisture can be a major cause of contamination, especially in environments prone to significant changes in temperatures that could allow moisture to form on the exterior or interior of system parts and components.
- Manufacturing Processes – New hydraulic gear pumps, replacement parts, and other components replaced on existing systems could introduce contaminants into the fluid.
- Metal Particulates – The gears and moving parts and components inside the system could introduce small metal shavings into the fluid.
- Operating Conditions – The type of environment where the system is being used could result in contaminants getting into the system.
- Open Fluid Reservoirs – When fluid reservoirs are not covered, water, dirt, dust, and other debris can get mixed into the fluid and be transferred back into the hydraulic system.
They are different types of components and equipment you can use to help identify various types of contamination in hydraulic fluid and systems. Some of these can be connected in-line directly to the system for ongoing monitoring. Others are portable and are designed to be temporarily connected or capable of testing a fluid sample.
It is essential to understand what sort of contaminants pose risks for your hydraulic systems in order to develop effective solutions to reduce and lower the effects of contamination. To illustrate, if you believe the source of contamination is water, and you implement processes to remove water, yet this is not the only source, your systems can still fail unexpectedly.
Solutions for Addressing Contaminants
One of the most frequently used solutions is the use of hydraulic fluid filters in the system’s reservoir or in other key locations in-line within the system to stop particles from damaging sensitive components. Filters can help remove solid particulates and prevent them from being re-introduced into the system.
However, it is essential to ensure you are using the right filters for your systems. If they are not the right ones, if they are the wrong sizes or not designed to work with your systems, they can cause a reduction in overall system efficiencies.
Filters restrict the flow of fluid as it passes through, this reduction in flow could cause a decrease in pressure and result in the system having to work harder and operate at higher temperatures. If you are using the wrong filters, you could inadvertently cause other types of damages to your hydraulic systems.
Another solution to address water contamination is the use of special additives or absorption elements. Some additives do help remove water from the fluid. Although, as water is removed, the effectiveness of the additives is reduced. In addition, certain additives could alter the dynamics of the fluid itself. Therefore, it is vital to guarantee you are selecting the right ones that are best suited for your particular type of fluid.
Absorption elements are somewhat similar to filters, except they remove water from the fluid. As the fluid is passed through the absorption elements, water is absorbed. However, if the water has fully dissolved into the fluid, then absorption elements are not very effective and other solutions have to be used.
Some organizations also use advanced technologies to remove contaminants from hydraulic fluids. These involve specialized equipment, like a vacuum dehydration machine, to remove dissolved water from fluids. This type of equipment can be used to treat new fluid before it is added into a system, as well as used fluid, so it can be recycled and reused.
Aside from these solutions, there are some other essential aspects to consider that play a direct role in reducing contamination:
- Proper Fluid Storage – Fluid should be stored in sealed containers in a climate-controlled environment. When sealed containers are exposed to extreme changes in temperatures, they can expand and contract drawing in moisture, contaminating the fluid. All containers should also be clearly marked with the type of fluid and what system(s) it is used in.
- Proper Fluid Handling – Steps should be taken to limit contamination when handling fluids. This could include wiping off reservoirs covers before opening them to add fluid, not adding fluid in dusty conditions, and so on. Furthermore, you should never mix different types of fluids together.
- Proper Fluid Selection – There are several different types of hydraulic fluids, with and without additives, for all sorts of hydraulics systems being used in a wide range of environments. There are even water-based fluids that are used in systems being operated in hazardous areas where explosions and fires are a major risk. You need to make sure the fluid you select is designed for your system(s) and environment.
- Regular Maintenance – Predictive and preventive maintenance can help identify potential system problems and fluid contamination. When problems are discovered the sooner they are corrected, the less costly they will be. Otherwise, if maintenance is not performed, something like a gear pump failure could potentially cause major and severe damages to the entire system and drastically increase repair costs.
- Regular Fluid Testing – You should take samples and test hydraulic fluid for contamination on a regular basis or use an in-line monitoring solution. Knowing the state of your fluid and level of contaminants will help you determine when you need to replace the fluid, filters and perform other types of maintenance.
As hydraulic systems will continue to be in high demand in numerous industries, developing proper solutions for monitoring and maintenance are ever-important in order to control the amount of fluid contamination. Doing so will allow you to get the most use out of hydraulic pumps and motors, as well as related parts and components.
For assistance in fluid selection, equipment and tools to reduce contamination, fluid filters, hydraulic system pumps, motors, parts, and components, please feel free to contact White House Products Ltd. at +44 (0) 1475 742500 today!
We stock one of the most diverse selections of hydraulic components and supplies, including over 6,000 different specifications of oil hydraulic gear pumps. We supply the entire United Kingdom with mostly next-day service, and we provide fast shipment to over one hundred countries worldwide.
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