Oil Filter Function
So what is an automotive oil filter?
An automotive oil filter is a replaceable component of an automotive that removes contaminants from engine oil.
Now, an automotive engine needs motor oil for cooling, lubrication, and to clean it.
As the engine runs, chemical and particulate contaminants are created, which can result in damage to the engine.
The contaminants get suspended in the oil as it runs through the engine.
When the contaminated oil is passed through the automotive oil filter, these contaminants are removed and clean oil comes out on the other side ready to recirculate in the engine. This way, the oil filter acts to protect the engine.
In simple term, the oil filter function is to protect the engine by filter the oil …
Oil Filter Working Principle
Ever wondered how an automotive oil filter works? Well, here is an explanation of how.
But before that, let me explain the parts that make the oil filter.
An automotive oil filter usually consists of a metal can (oil filter canister) and a gasket by which it’s held to the mating surface of the engine.
The gasket itself is held by a metal plate that’s perforated with a series of holes. A central hole with threads mates with the automotive engine block and the oil filter’s assembly.
A filter material, usually synthetic fiber, is found inside the filter canister. This is the material that removes contaminants from the engine’s oil.
How does filtration occur?
Oil containing contaminants is pumped from the engine through the perforated metal plate into the filter. As it goes through the filtering media, impurities are trapped.
Clean oil comes out of the media or membrane and into the central hole. From here, it goes back to the engine.
Filtering material can be primary or secondary. Primary filter media can remove particles of size between 25 and 30 microns while secondary materials are capable of filtering particles as small as 5 to 10 microns.
A filter will work for as long as oil can flow through it.
With time, contaminants build up to a point where oil cannot get through.
During such situations, the overflow valve that’s incorporated in an oil filter comes into operation. It allows oil to still reach the engine by bypassing the filter, but without being cleaned of impurities.
At this point, the oil filter would be needing to be changed to protect the engine of your car.
Types Of Oil Filter
Oil filters come in many types with differences ranging from the mode of action, kind of filter material, working principle, and durability to cost.
By the automotive filter industry classification, the oil filter can be centrifugal or full flow type, with the full flow oil filter being the most commonly used.
Centrifugal oil filter
The centrifugal oil filter has a rotor sleeved on a shaft and has two nozzles with opposite spray directions. When the oil enters the rotor and exits the nozzle, the rotor rotates rapidly, so that the oil in the rotor body is cleaned. The impurities in the oil are centrifuged onto the inner wall of the rotor, and the oil from the nozzle flows back to the oil sump.
Centrifugal oil filters are characterized by stable performance and no need to replace the filter element. As long as the rotor is removed regularly, the dirt deposited on the rotor wall can be cleaned and reused. Its life can be equal to the engine. Its shortcomings are the complex structure, high price, heavyweight, etc., which have high technical requirements for users.
Full flow oil filter
The full-flow oil filter is divided into replaceable, spin-on, bypass type.
In order to allow all the oil entering the main oil pipe of the engine to be filtered, the oil filter is connected in series with the main oil tube of the engine.
Bypass Oil Filter
The Oil filter parallel to the engine main oil tube. It is a refine oil filter in the engine, which is generally used in conjunction with full flow.
The bypass oil filter only filters oil from 5% to 10% of the oil supply of the oil pump.
Spin on oil filter
The spin on oil filter consisting of a filter element and a can housing and cover, it is the most common oil filter types on the market.
It can be directly screwed onto the oil tube of the engine by the thread on the cover to filter the oil, or it can form a spin-on oil filter assembly with the filter base.
Most of the low-power engines use full-flow filters, and the larger-capacity diesel engines use full-flow and bypass flow filtration devices.
Canister oil filters are usually made of steel and are screwed directly to the engine.
They consist of metal can, filtering media and base plate for attachment to the engine. Cartridge oil filters are a type of filter that’s inserted into a filter housing. They are formed of filtering media and other components that allow them to be fitted into a filter housing.
Automotive oil filters can be categorized according to the filter media, or according to the methods used to carry out filtration.
The Other Types of Automotive Oil Filters According to the Filtering Method
Primary Automotive Oil Filters
Primary oil filters are also called full filters. They filter 100% of the oil coming from your engine and are the type that most manufacturers will install on their automotive. They offer less restriction to oil flow by allowing extremely small particles to pass through. They will also incorporate a valve that allows oil to bypass the filtering media should it become clogged.
Secondary Automotive Oil Filters
Secondary oil filters clean from 1 to 10% of the motor oil. They work alongside the primary oil filters to ensure the oil returning to the engine is further filtered of contaminants and, therefore, cleaner. A car may or may not come installed with a secondary oil filter. You can always fit one in the case your car doesn’t come with a secondary oil filter installed.
Centrifugal Automotive Oil Filters
They separate impurities from oil by use of rotation. A rotor rotates at high speeds with the rotation causing impurities to be thrown towards the inner walls of the rotor. This separates contaminants from oil passing through the filter and clean oil passes on leaving behind particles and other impurities.
Magnetic Automotive Oil Filters
Magnetic oil filtering involves the use of a permanent magnet to attract ferrous metal particles out of oil. This method can remove very small metal contaminants. The only problem with it is that it doesn’t detect non-ferrous particles, such as dust, which pass onto the engine and cause damage. These filters do not need to be replaced; you only clean them.
Thermal Chamber Automotive Oil Filters
These filters remove contaminants from motor oil by filtering and also by heating the oil to destroy some types of impurities. To heat up the oil, these type of oil filters use electricity.
With the many kinds of oil filters available, you may be asking,
“What oil filter do I need in my car?”
Well, the type of oil filter your car needs will depend on the size and type of engine the car comes equipped with.
Oil filter compatibility will also depend on the manufacturer; different manufacturers make cars that only use specific oil filters. I would advise that you use an oil filter made for your type of car and engine to achieve the best results.
Oil Filter Specification
If you are going to buy oil filter in bulk from oil filter wholesales or oil filter distributors, you may only need to concern the dealer’s reputation. But if you are planning to purchase oil filters from the oil filter manufacturers, then you got to be professional.
There are thousands and thousands of oil filter manufacturers in global, you got to keep an eye on their products quality.
To help you be a professional oil filter buyer, we offer you this professional oil filter manufacturing specification to understand what are the requirements for a qualified oil filter.
1. Filter seals should be high oil temperature resistant elastic materials.
2. The metal parts(the inner and outer surface of the Oil filter can, crepe cover, seal fixing plate, spring) of the oil filter should be treated with anti-rust treatment, and the surface is plated and the coating is free from rust and peeling.
3. Oil filter resistance to hydraulic pulse fatigue：On the test bench, tighten the tightening torque specified by the manufacturer. The peak pressure of the oil pressure is 0.8 MPa. After the pulse cycle is 15,000 times, the outer casing of the filter should be free from deformation. The joint is not allowed to seep and the parts should be free from damage.
4. The original resistance of the oil filter shall not exceed 0.025 MPa at rated flow. The original resistance of the oil filter can also be changed according to the buyer’s request.
Qe—-Rated volume flow, the unit is L/min
k—-modulus, k=0.006L/(min ? cm2);
F—- effective filter area of the oil filter media, the unit is cm2
5. The filtration efficiency of the oil filter is tested by the standard test of the oil filter, and the original filtration efficiency should be no less than 60%.
6. The clogging life of the oil filter shall not be less than 3 h when the pressure drop reaches 0.07 MPa or 70% of the bypass valve opening pressure.
7. The opening pressure of the bypass valve in the oil filter shall comply with the provisions of the production drawings.
8. The bypass valve in the oil filter should be tested for tightness. When the pressure difference between the valve and the valve is 0.03 MPa lower than the specified opening pressure, the oil leakage should not exceed 0.2 L/min.
9. If there is a one-way check valve in the oil filter, the sealing performance is 600mm ± 10mm oil column pressure head, and the oil leakage of 6h should not exceed 0.1L.
10. Under the action of 0.35 MPa pressure drop, the central part of the filter element should be free of deformation, and the filter element should have no defects such as cracking, perforation and degumming.
11. The oil filter should be tested for high oil temperature resistance. After soaking for 192 hours in 135 °C oil, the filter element should be free of degumming and be cracking. Other parts should not be permanently deformed or partially damaged.
12. The static pressure burst test of the oil filter shall be kept at a pressure of 5 MPa under the action of 1.5 MPa oil pressure, and the outer casing shall be free from damage and oil leakage.
13. The inside of the oil filter should be cleaned. The cleanliness limit is: the rated volume flow should be less than 10L/min and should not exceed 3mg/ (L/min); the rated volume flow should be more than or equal to 10L/min should not exceed 2.8mg/ (L/min).
14. The connection screw hole of the oil filter and the main unit should meet the requirements of the product drawings.
15. The outer surface of the oil filter should not have the scars and burrs, and the surface of the paint should not be exposed to defects such as bottoming and hanging.
Although it’s an official industry standard for oil filter manufacturing, not every oil filter manufacturer will in compliance with this standard, even for big oil filter companies. Because in the real oil filter manufacturing process, some requirement of this standard is unpractical. But it does not affect it’s a good oil filter study materials.
Again, we wish you can be more professional and bargain a better price for purchasing oil filters in bulk after learning the oil filter specification.
Oil Filter Test
Air pressure tightness test
The purpose of this test is to check if the filter leaks.
Step#1. The oil filter will be installed in the position shown in the figure, and the inlet will be connected to the air supply. Generally, the detection device can connect 4 filters at the same time.
Step#2. Raise the water level and sink the tested oil filter into the water.
Step#3. Open the regulating valve, and when the pressure reaches the specified value, the holding time is not less than 10s, and visually check whether the tested filter has bubble escape.
Step#4. The inspector observes whether the filter is immersed in water. If there is leakage, it is a non-conforming product, and the leaking part should be recorded; otherwise, it is a qualified product.
The airtightness test is the simplest and most important test of the filter manufacturer. If the oil filter does not pass this test, it is a non-conforming product and needs to be reworked.
Cut open oil filter
The debris contained in the car’s oil filter can serve to indicate the health of the engine.
Some DIYers may be interested to inspect the particles that were filtered to determine the condition of your car’s engine and what steps to take.
Also, most oil filter buyers do not have their own oil filter test equipment, the most direct way to check the oil filter is cut open oil filter.
One way or another, if you want to figure out the inside of the oil filter, you need to cut open the oil filter.
You will need a special kind of tool known as an” oil filter cutter.”
Before opening the removed oil filter, you should have the oil in it drain for some hours. After it’s drained, take can that makes the oil filter and position the cutter around it, but in a way that the cutter will cut into the oil filter canister near the mounting gasket.
Next, adjust the cutter’s knob so that the two bearings of the cutter hold the canister tightly. Now rotate the canister a few times, then tighten the cutter once more.
Repeat this several times until the cutter cuts through the canister fully to allow you to retract the filter element or contents.
Remove the mounting flange to expose the inside of the filter. Get the filtering element out using the fingers. Spread the filter material to expose the filtered particles. Trapped debris can be seen on the pleats.
When cutting open an oil filter, use gloves to avoid soiling your hands. Also, allow the oil to drain before opening so it doesn’t accidentally splash on you.
In case you do not have the oil filter cutter, use the tools you have with you such as a hacksaw and a pair of tin snips.
Discard the used oil filter in a safe way once you’re done.