Hydraulic filters serve an essential purpose in keeping hydraulic fluid free of contaminants. It is estimated that approximately 75% of all power failures in fluid power systems are attributable to some form of contamination, which occurs when there are too many pollutants in the medium itself for normal operation to take place.
There are a number of reasons why fluid can become contaminated, including poor overall plumbing, long periods of usage and wear on all of the components, and even direct contamination, which is introduced to the system by new fluid or new components. There are many other ways in which contaminants can be introduced into a fluid system, and if they aren’t filtered out by a good hydraulic filter, they will eventually degrade the performance of the system and possibly shut it down altogether.
What is a hydraulic filter?
A hydraulic filter is a simple device that is designed to screen out pollutants and contaminants from fluids so that the system being operated remains capable of carrying out normal functionality. There are several kinds of filters, the most popular being bag filters, screen filters, and magnetic filters.
A bag filter is constructed of a cloth bag through which hydraulic fluid is pumped, with the clean fluid emerging on the other side and the solid contaminants being trapped inside the bag. This is a very useful type of filter when you’re trying to eliminate rust, dirt, and particles that have been introduced into a system by an agent like a cylinder rod.
Screen filters are comprised of a number of tiny wires that have been woven together in order to create a kind of metallic fabric. This type of filter can be constructed so that it has a very specific pore size, and so it can be used in a variety of very specific applications.
Finally, magnetic filters are those that have charged plates that attract all kinds of metallic pollutants.
When you’re buying a hydraulic filter, it’s very important to know whether a housing is required or not with the filter. It’s also good to know what your alignment options are when choosing a filter. If you have the filter, outlet, and inlet all lined up together, this kind of arrangement is known as an in-line alignment. An off-line alignment is created when the filter is outside the main hydraulic systems loop. Still another type of alignment is called the duplex, in which there are two filters that have been combined.
All these filters can be very useful due to the fact that they can be changed with little or no disruption to an operating system. A configuration known as a return line configuration is designed for the purpose of catching all pollutants that have been introduced to a hydraulic system. Filters are rated according to their effectiveness, and those with the lowest ISO cleanliness rating will remove more contaminants and increase the life expectancy of any hydraulic systems components — often by a factor of two or three.
Another way of measuring the effectiveness of a filter is by its beta ratio, which is calculated by dividing the number of contaminant particles upstream by the number of contaminant particles downstream. When you subtract the number by one, divide by the beta ratio, and then multiply the result by 100, you can obtain any filter’s percentage of efficiency for any kind of contaminant. The greater the beta ratio is, the more effective the hydraulic filter will be.
Why is it important to change them?
There is a very simple reason why it is important to regularly change your hydraulic filter. It has been estimated that during every minute of operation, something like one million particles sized greater than one µm will be introduced into any given hydraulic system. These particles will eventually cause significant damage to the hydraulic system by contaminating the oil and by being circulated throughout the rest of the system.
By changing your hydraulic filter frequently, you are eliminating all those trapped contaminants so that they can’t be pushed through the system. Because such hydraulic filters serve to clean the oil regularly, they can minimize the damage inflicted by all these contaminants in the system. Hence why hydraulic filters are often rated according to their ability to trap these pollutants and remove them from circulation.
Most hydraulic systems these days are equipped with at least two hydraulic filters and very often more than that. Some hydraulic filters are set up between the actuators and the pump, and these are referred to as pressure filters. When hydraulic filters are set up between the actuators and the tanks or reservoirs, these are known as return line filters or low-pressure filters.
Where are hydraulic filters located on a John Deere tractor?
On a John Deere tractor, you will need to change the hydraulic oil and filter regularly so as to keep the tractor running efficiently and to prevent contaminants from degrading your tractor’s performance. The hydraulic filter itself will be housed in a cylindrical casing at the side of the engine, and this should be replaced at the same time that you replace the hydraulic oil. Make sure to use an oil viscosity based on what you expect the air temperature to range between before the next change. In order to do that, you’ll have to remove the drain plugs so that oil can drain into a pan and be disposed of. Then you can replace your hydraulic filter and refill your system with the appropriate transmission hydraulic oil.
Many owner/operators of machinery consider it something of a hassle to periodically change their hydraulic filters and their hydraulic oil. However, changing the oil and the hydraulic filter is essential to ensuring a longer life for your machinery, and if you don’t commit to regularly changing these two, it’s entirely possible that contaminants will be introduced throughout the system.
When this happens, you can expect the operational life of your machinery to be significantly reduced, and you will probably see a reduction of performance as a result. For the little trouble that you encounter while changing hydraulic filters and hydraulic oil, it is well worth it so as to prolong the life of your expensive machinery and save a lot of repair time and money. If you need help with hydraulic cylinder repair in the Houston, TX area, contact the experts at Sapphire Hydraulics for more information.