Hydraulic fluid contamination is a common problem during hydraulic system running. But how to prevent this situation and reduce the contamination? This article will introduce you to the 6 common contamination and tell you how to prevent it in your business.
1. 6 Types of Hydraulic Fluid Contamination
There are many reasons that may cause hydraulic fluid contamination, including internal and external factors.
1.1 Original Contamination
We all know the materials of hydraulic tanks or other parts are metal like carbon steel, cast iron etc. When these metals are cut into different sizes and shapes, it will generate lots of metal shavings. Also, when using the metal parts to welding the hydraulic parts, there will form a lot of welding slag.
Although the manufacturer will clean up the metal shavings, welding slag, or lubricant after
production. There is still some unnoticed contamination inside hydraulic parts.
On the other hand, the packing used tape, foam board and wooden box will also create contamination. These easily overlooked details always become the “prime culprit” of hydraulic fluid.
1.2 Contamination in Operation
When starting up the hydraulic system, all the hydraulic system parts start to move. Hydraulic fittings rub against each other and release metal chips. These metal chips may follow hydraulic fluid into the hydraulic tank and pollute all the fluid.
This situation always happens when you receive the new hydraulic system equipment. During the running-in phase, when you constantly adjust the new hydraulic system or replace parts, the constant wear will aggravate the contamination of the hydraulic fluid.
Along with the long operation of the hydraulic system, the seals will wear out. Aging polymer parts will decompose to produce chemicals that react with hydraulic fluid, thus making it polluted.
1.3 Air Contamination
Air is also an important factor that causes hydraulic fluid contamination. If you find there are many bubbles in the hydraulic fluid, which means the hydraulic fluid has been polluted by air already. Air can affect the compressibility of hydraulic fluid. The longer the hydraulic fluid is exposed to the air, the more unstable the operation of the hydraulic equipment will be.
Why are there a lot of bubbles in your hydraulic fluid but it is not exposed to air? Maybe it is because you didn’t bleed the air out of the hydraulic tank in advance and inject too little fluid. This will also cause too much air in the hydraulic hydraulic tank to pollute the hydraulic fluid.
1.4 Water Contamination
Water contamination always happens too. Especially when you run the hydraulic system under a high humidity environment and make it more serious. The sign of contamination by water is the hydraulic fluid starting to look like “mike”. If this situation happens, replace the hydraulic fluid immediately.
If you keep the hydraulic system working under the high humidity it will also reduce the hydraulic fluid lubricity, thus forming sludge to clog the filter. Water can also cause a more serious issue: oxidation. The water can make the metal surface oxidation or even corrosion. This damage is irreversible and needs time to maintain and fix.
1.5 Chemical Contamination
Actually, hydraulic fluid is a type of chemical material, which means it can do natural decomposition. As time goes by, hydraulic fluid will decompose into different substances to damage the hydraulic system.
If you keep using the hydraulic fluid under a high temperature or pressure environment, then the situation above will appear faster. In addition, the high temperature can also separate the air from hydraulic fluid to increase the saturated vapor pressure, which will cause cavitation and damage the hydraulic tank.
Apart from the chemical pollution caused by the hydraulic fluid itself, chemical reactions will also occur between different types of hydraulic fluid. For example, if you inject a different type of hydraulic fluid into the hydraulic tank with little original hydraulic fluid. If the additives in the two fluids are incompatible, then a chemical reaction will occur and cause contamination.
1.6 Particle Contamination
We all know the hydraulic system is widely used in construction machinery. The workplaces of construction machineries are always dusty and sandy. So it is easy for dirty particle drift in the hydraulic fluid.
There are two situations that can lead to particle contamination particularly. One is that the hydraulic system is not sealed tightly and leaves a lot of gaps for particles to get in. Another situation is not cleaning the hydraulic tank before injecting the fluid, then dust and sand attached with hydraulic fluid into the hydraulic tank.
There will be no problems in the short term. But if you do not clean regularly the particle will block the fluid filter thus burnt the hydraulic pump.
2. How to Prevent Hydraulic Fluid Contamination?
Here are some measures to help you prevent contamination before you meet the same questions like the above.
2.1 Totally Cleaning before Use
The totally clean we suggest is about two dimensions, including the cleaning of hydraulic fluid and hydraulic system.
First, the cleaning of hydraulic fluid means filter the hydraulic fluid before use. Usually, a “healthy” hydraulic fluid is a clear and transparent color, which can help the hydraulic system run stably and extend the service life.
If you find the new hydraulic fluid stored it becomes black and muddy. The reason for this situation may be that impurities or contaminants enter the fluid. Just using a fluid filter machine can easily get a clean hydraulic fluid. This method can also work with the original dirty fluid in the hydraulic tank.
Next, clean up the hydraulic system. When you receive the new hydraulic equipment or accessories, it’s necessary to clean up the remaining stains. Use sandpaper to remove welding slag from the inner surface of hydraulic equipment, then use specific cleaning agents to remove the fluid stains on the surface.
Cleaning the hydraulic system is not a complex job but needs a lot of patience. You can use different tools to help with the cleaning job such as brush, scrapers to keep the hydraulic system clean. What you should notice is do not use strong acid or alkaline cleaners because they will corrode the metal surface of equipment.
2.2 Change Fluid in Time
When you find the fluid color has become deeper, unclear or bubbles on the surface, it is time to replace the original fluid for new fluid. Don’t save the cost of hydraulic fluid without replacing it. Once the hydraulic system is damaged due to the contaminated fluid, the repair cost will be a few times higher.
Before injecting the new fluid, you need to clean up the hydraulic tank completely. Then pour the hydraulic fluid through a filter(over 120μm) into the hydraulic tank. Don’t pour too fast that will cause fluid spillage and corroded vehicle parts. After injection, remember to make sure the hydraulic tank is sealed properly.
2.3 Regular Maintenance
The regular maintenance jobs are very important to the healthy working of a hydraulic system. We suggest you do the maintenance from 4 aspects.
First, check the wear condition of seals regularly. The seals are very easy to wear and tear when the hydraulic system is working. You better replace the seals every 500 days. If the status of seals are bad, please replace them immediately.
Second, confirm whether the input and output fluid ports are sealed or not. You can check the sealing by observing if there is any fluid leakage from the port gaps.
Third, make sure there is no fluid leak from the hydraulic hose by observing or hand touch to inspect the sealing situation. Or you can use pressure testing to ensure the pressure of the hydraulic hose in a normal range.
Fourth, test the hydraulic fluid quality regularly. Through testing the moisture content, oxygen content and particle count to confirm the hydraulic fluid to keep the hydraulic fluid clean.
2.4 Proper Storage
The proper storage of hydraulic fluid should meet 3 conditions. The storage space must be sealed to avoid the dust, debris or other particulate matter entering the hydraulic tank. Then, avoid storing the hydraulic fluid under high temperature and lay the storage container on its side. Finally, to avoid a humid environment, high humidity is not a good thing for hydraulic fluid.
In addition, we recommend not storing too much hydraulic fluid. If you can not use it up in time then it will cause the hydraulic fluid to break down, thus leading to cost losses.
Conclusion
The cleanliness of hydraulic fluid can influence the health of the hydraulic system a lot. Although it is easy to cause hydraulic fluid contamination, you can still prevent the situation by many methods to extend the service life. Target is a professional hydraulic power pack manufacturer. If you have any other puzzles about hydraulic fluid contamination, please contact us.
