Oil filters
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Our comprehensive commercial offer for oil filtration
Types of oil filters
Combustion engines
In internal combustion engines, oil is used for lubrication. The particles resulting from combustion are filtered out in the oil filter. To prevent damage to the machine or engine, the oil filter must be changed in good time. By adding bypass filters or centrifuges, system components can be filtered even more finely.Hydraulic systems
For hydraulic systems, a distinction is made between two types:- Function protection filtration: Coarse filters for simple systems used only for function protection.
- Wear protection filtration: Very fine filtration is required for complex agricultural machinery, construction machinery, excavators, etc.. This reduces abrasion and thus wear.
Overview of oil filter types
- Main stream oil filter
- Offline oil filter
- Lifetime oil filter
- Suction filter
- Pressure filter
- Return flow filter
- Return suction filter
- Inline filter
- Police filter
- Centrifuge
- Free jet centrifuge
- High pressure filter
- Medium pressure filter
- Low pressure filter
- Spin On
- Sieve
Applications of oil filters
Oil filters are used when oils are required in engines, machines, plants and systems. The oils are used for lubrication, cooling, power transmission, sealing and flushing as well as corrosion protection. In the process, they are usually kept in constant flow and circulated. These oil-hydraulic systems, which are equipped with an oil filter, include the following systems:
Industrial machinery
Injection molding machines
Machine tools
Tunnel boring machines
Eroding machines
Compressors
Presses
Commercial vehicles
Marine engines
Tractors / Agriculltural machinery
Forestry machinery
Trucks
Car engines
Construction machinery
What is the function of the oil filter?
MANN oil filters
MANN oil filters stand for:
Hengst oil filters
Hengst filters stand for high performance and low wear. Thanks to their robustness, durability and high serviceability, you can rely on Hengst oil filters! In our large Hengst oil filter assortment, you can quickly and efficiently find the right filter for your machines.
So that you can rely on your machines and engines, you need oil filters that work reliably even under high loads. Hengst oil filters can ensure this thanks to their optimum filtration, long service lives and high flow rates.
Hengst oil filters stand for:
More oil filter manufacturer
In addition to our German brand partners, you will also find many other high-quality oil filters in our range. These include Donaldson, Fil Filter, Sotras, UFI, Fleetguard and other oil filter manufacturers. Here, too, our experts will be happy to advise you on the various advantages and disadvantages as well as intended uses of the different oil filter manufacturers and product variants.What are the designs (types of construction)?
Spin-on cartridge / Spinn-off filter / Spin On
The most widespread design is the spin-on oil filter. The spin-on filter is screwed directly onto the engine, transmission, system or filter flange by means of a double nipple. The connection is extremely simple. Spin-on oil filters are produced by the millions every day, so production costs are relatively low due to the high production volume.
Numerous filter finenesses can be represented in the spin-on oil filter by means of different filter media. Filter media are mostly cellulose and synthetic media. Spin-on oil filters are often equipped with a bypass valve. This opens at a defined pressure and allows the oil flow to pass unfiltered past the filter bellows. This prevents the Spin On Filter from preventing the flow of oil, resulting in no or too little oil flowing through the filter - better dirty oil than none at all. This circumstance can occur if the oil is too cold and thick. But it can also occur if the filter medium becomes clogged with too much dirt.
Filter cartridge / Filter element
A filter insert or filter element usually has a cylindrical design. The end plates are at the top and bottom, and the filter bellows is glued between them. The flow through the bellows is from the inside to the outside or from the outside to the inside. In order to obtain as much filter surface as possible in the filter, the bellows is usually folded (pleated).
Subtleties in oil filtration
Main-flow oil filtration
Motor vehicles, industrial engines, and compressors have a main-flow oil filter that can reliably remove harmful particles. If properly designed, its performance is sufficient to protect the equipment and consumers from excessive contamination between service intervals. An oil pump sucks or pumps the oil from a collecting tank or the oil pan to the consumers or the lubrication and cooling points. An oil cooler may also be used to cool the heated oil. The top priority is to ensure that the system is supplied with sufficient oil. A bypass valve ensures that oil will continue to flow to its destination even if it cannot be pumped through the filter medium. Since an open bypass valve – and thus a flow of unfiltered oil – cannot usually be monitored, it is important to replace the oil filter at the specified maintenance intervals.Partial-flow oil filtration
The majority of the tiniest dirt particles are not caught by the main-flow oil filter. However, in the long run, they can cause the same kind of wear as the larger particles that are retained in the main-flow filter. A dreaded consequence of this is “bore polishing”, whereby the smallest particles act like a polishing paste and make the cylinder bore surfaces and bearing points so smooth that an oil film can no longer adhere to them. To prevent this, these ultra-fine particles can be removed from the oil circuit by an additional partial-flow oil filter. This involves permanently diverting a small amount of oil from the main flow and pumping it through a second, finer filter. This partial-flow oil filter also requires regular maintenance and must be replaced after a specified number of miles or operating hours. Another very effective way to filter oil in the partial flow is to use a centrifuge, in which a rotor is accelerated to speeds as high as 10,000 revolutions per minute. Due to the resulting centrifugal forces, the finest particles are forced out of the oil and collected in the so-called “filter cake” on the rotor wall. The filter cake can then be removed from the centrifuge. These centrifuges are usually driven by the oil pressure alone and do not require a separate drive.Hydraulic systems
Within hydraulic systems you will typically find suction filters, pressure line filters, return filters, and breather filters as well as strainers. Pressure line filters are generally subjected to high pressures and are therefore installed inside pressure-resistant housings. The oil filter element in the housing is replaceable and is usually designed to withstand high differential pressures, depending on the application.Oil filter maintenance
Maintenance instructions for oil filters can usually be found in the operating and maintenance manuals provided by the respective machine or plant manufacturers. When the specified maintenance time is reached, usually after a certain number of miles or operating hours (as specified by the manufacturer), the filter should be serviced. The recommended maintenance intervals are typically based on an assumed dirt load and the available filter surface.
However, maintenance intervals calculated in this way are only recommended values. In the case of more challenging operating conditions, shorter maintenance intervals may be necessary. At least one filter change per year is usually recommended. One reason for this is that the adhesive joints in the filter may perish over time. In the vast majority of cases, the filter element or spin-on is simply replaced with a new filter. In some cases, strainers can also be washed out or cleaned and then reused. The filter should be in a depressurized state for this purpose. Engines or plants that cannot be shut down usually have a parallel filter through which the oil can flow during maintenance of the dirty filter. Regular maintenance of the filter is not a necessary evil, but rather essential to ensure long-term operational reliability of the machines and systems.
As already mentioned, it is usually not possible to determine the precise technical properties of a particular filter from the outside. Therefore, you are strongly advised to only use approved filters when performing maintenance work. In most cases, any problems with the filter will not be detected immediately – and often only after many miles or hours of operation. By this time, the resulting damage and subsequent costs usually far exceed the price of a suitable filter. Many manufacturers also offer maintenance or service packages. These contain all the filters – in the right quality – needed to complete the filter change.