Hydraulic Filter

Hydraulic oil in a reservoir may look clean to the naked eye, but silt contamination particles too small to see can still wreck pumps, cause valves to stick, and erode cylinder bores. In many facilities, components may take the blame for problems in error, when contaminated fluid is the culprit. Research shows that 75% of mechanical failures are caused by system pollution, which is the reason of demanding for high efficiency hydraulic filters is increasing. The best fluid power systems are strategically engineered by hydraulic filter manufacturers to ensure that hydraulic oil is filtered properly at each stage of its journey through the circuit. Almost every hydraulic system contains more than one hydraulic filter.

According to a study by Damen Technical Agencies, Industrial hydraulic Filters replacement are fluid filter in hydraulic system. Irrespective of operating conditions like high pressure, low pressure, highly viscous oil, or highly contaminated oil, It is used in heavy truck, off-highway, agricultural and construction vehicles and equipment depend on hydraulic fluids to power many of their critical functions. The more functions are:

1. Improve the cleanliness of the hydraulic system. There are suspended particles in the liquid of each hydraulic system.It can’t work without each processing of filtering of the hydraulic filters.

2. Extend the service life of the accessories(such as valves and hydraulic motors). There are about one million particles who are bigger than 1 μm (0.001 mm or 1μm) entering into the hydraulic system every minute. As the hydraulic oil is easy to be polluted, these particles may damage the accessories of the hydraulic system. Hydraulic filters protect the using oil , other hydraulic oil and lubricant from being polluted by the particles continuously.

3. Reduce the shutdown time for the hydraulic system. Pollutants grind and wear on the surfaces of moving parts, bringing more particles into the system. These pollutants cause more than 70% of the system downtime.

4. Improve the performance of the system and keep the system running smoothly especially mixing borosilicate and glassfiber media to produce solid, durable and efficient filter elements. The filter medium combines high flow rate and high dirt retention without affecting the service life of the filter element.

5. Protect the components of the hydraulic system and reduce the maintenance cost of the components. The wear is the contamination of metal components in hydraulic oil, for example, the presence of iron and copper will speed up its degeneration, or the possibility that plastic and rubber particles from abraded machinery become detached,Rust or other oxidation may occur and damaging chemical compounds may form in the medium.

6. Maintain a good environment of the hydraulic filtration system to ensure the accurate operation of the system.

7. Keep hydraulic oil clean, dry and cool. Water, especially “free” water that is insoluble in oil, will cause corrosion, change viscosity, reduce lubrication and increase oxidation

Hydraulic Filter Type

Hydraulic oil filters have numerous advantages in the hydraulic industry. They are can classified in different types based on the applications, filtering method, size of pores, location of the filter and the amount of oil filtered. There are three kinds of filters in the hydraulic system: hydraulic filter, oil filter and air filter. The oil can be used by the filter to remove the impurities in the oil, maintain the oil cleaning and ensure the normal operation of the hydraulic system; Air filter is mainly used to filter the air entering the open oil tank to make the air clean.

According to the different filtering precision, there are four kinds of hydraulic oil filter: coarse filter, common filter, clean filter and ultra fine filter. They can filter out the impurity particles with nominal size of over 100 μm, 10-100 μm, 5-10 μm and 5 μm respectively. The filtering precision of oil is related to the type of hydraulic system and its working pressure. Generally speaking, the hydraulic control system is better than the hydraulic transmission system The requirement of filter cleanliness is higher in high-pressure system than in low-pressure system.

According to the different types of filter elements, the commonly used oil filters in hydraulic system are mesh type, linear gap type, paper core type, sintering type and magnetic type. Many hydraulic filter manufacturers classify based on pressure, fluid type, flow rate, resistance, percentage of contaminants, and ideal cleanliness. Mostly we classified by the performance of each hydraulic filter, which is measured by its pollutant removal efficiency (i.e. high dirt retention capacity).The hydraulic oil filter specification:

Suction strainers, hydraulic strainer, or sump-type filters, are typically found in the hydraulic fluid reservoir before the hydraulic pump.  Their only real use is to keep cigarette butts, moths, nuts and bolts, and the like out of the pump.The hydraulic strainer’s large size contaminants easily can be eliminated instead by keeping the reservoir sealed and by using a filler-breather and return-line filter.  

Hydraulic Air Breather Filter is located on top of the tank-reservoir. It is composed of air filter and oil filling filter, which can not only prevent the particle pollutants from entering the system through the breathing port of the oil tank, but also prevent the particle pollutants from mixing in the oil filling process.

Hydraulic and Transmission high pressure filters, also called Transmission Filter, are designed to maximize system cleanliness, and provide the best machine performance and component protection. These filters are high pressure hydraulic oil filter element. There is no bypass valve in the filter.

When a hydraulic component fails or when the hydraulic system is opened, there’s a high risk of contamination being introduced which can be detrimental to the performance of the machine and its service life. It’s essential to pre-filter the fluid to re-establish its proper cleanliness. Return line filters are available in spin on filter and filter elements’ styles.

Pilot filter is used in excavator. The filter element is mostly near the hydraulic pump, putting in the hydraulic filter housing. It will be called filter assembly. It is used to filter the impurities in the pilot oil. The pilot oil controls the operation of each valve element and hydraulic system.

Know More Tamfiney Hydraulic Filters? Cross Reference, Dimentions, Weight and so on…

Working Principle

The hydraulic fluid enters the inlet at the bottom of the pipe from the inside through the filter element to the outside and exits at the side outlet. When a new and recently cleaned filter element is installed in the housing, the indicator light will indicate that it is “clean”.

When the dirt is deposited on the surface of the filter cartridge, the differential pressure between the inlet and outlet of the hydraulic filter element increases. The bypass piston senses a pressure difference. The piston is held by a spring. When the element needs to be cleaned, the differential pressure is high enough to compress the spring and force the piston away from the seat. The movement of the piston points the telltale indicator to the “need to clean” position.

When this signal occurs and the element is not cleaned, the differential pressure continues to rise, causing the piston to expose the bypass passage in the cap. This action limits the differential pressure rise to a value equal to the spring tension and the fluid bypasses the filter element.

Our Features

As one of the most professional hydraulic filter suppliers in China, Our classic features are:

Filter medias fineness:1,3,6,12,25μ ……As one of the Most professional hydraulic filters suppliers

High quality filtration efficiency reach up to 98%

Working life 800-2000h

Adopt multilayer structure filter paper, with high filtration fineness

Its glass fiber layers are carefully set and processed, filtration effect is better.

Specification and variety is completed,can meet all kinds of filters need

Special dust-free paper folding workshop to ensure maximum filtration efficiency for each filter.

Tamfiney hydraulic filter elements from our aftermarket catalogue can guarantee installing and an extremely high degree of filtering of corpuscular pollutants.

The filter media is pleated by machine regularly. This unique pleated design maximises the surface area whilst ensuring consistent flow, and delivering exceptional particle retention efficiency. As the hydraulic oil passes through the pleat pack, larger unwanted particles such as dirt and impurities are removed.

A new type of Stat-Free filter element is used to combine the excellent static characteristics with the filtering performance, which is a new type of filter mesh pack and element design enables the filter element and the fluid in the system operation to generate an unparalleled low charge.

Our hydraulic filtration performance under any pressure. Protect expensive hydraulic components with Tamfiney complete line of spin-on, cartridge-style and in-tank hydraulic filters.


Synthetic glass fiber media for greater filtration efficiency and higher dust-holding capacity

Natural fiber cellulose

Stainless steel wire-mesh

Water absorbing media

Requirements for filtering accuracy of various hydraulic systems

Filter precision is an important performance index of filter, which is usually measured by the nominal size of the impurity particles, that can be filtered out.

Have more questions about how our filters can benefit your business? Click to contract

Why Choose Us

1.Be your OEM suppliers for hydraulic oil filter elements. Whether for standard, custom or special filter design, Tamfiney hydraulic oil filter offers a perfect filtration solution.

2.As a hydraulic filter manufacturer, no cutting corners, more wrinkles and surface area to achieve higher dirt retention ability.

3.High collapse resistance, even under high pressure difference, the filtration efficiency remains consistent to remove particles and water

4.There are many hydraulic filter element suppliers in china. We strictly implement reliable tolerances in the design and manufacturing of hydraulic components such as hydraulic oil filters, in order to improve their pollution sensitivity.

5.It can be proven without any worry that Tamfiney hydraulic oil filters can meet such system requirements.

6.You can safely place your hydraulic system under the protection of the Tamfiney hydraulic oil filter. Because they are specifically used for various hydraulic filters in hydraulic systems.

7.Complete hydraulic oil filter cross reference catalog, complete record of filter models used interchangeably. Combining with first-class hydraulic oil filter brands. We can quickly search for images and product information in our online catalog. Save time for distributors and customers, assist technical teams in making accurate procurement decisions. For example, If you are finding tractor filters. You can put the tractor hydraulic fluid cross reference number in our Cross Reference Searching line directly. It will come out if we have.

8. Tamfiney Filtration produce products that meet market requirements and the highest quality standards, backed by modern machinery and a large production capacity. Filtering technology is based on in-depth basic research, technical problem solving, specific customer requirements, and international standardization.


Mobile Hydraulics: 

Construction Machinery

Agricultural Machinery

Municipal Machines

Fork Lifts

Mining Machinery

Industrial Hydraulics:

Machine Tools

Injection Moulding Machines

Paper Industry

Power Plant Technology


Automotive Industry

Iron/Steel/Metal Production

Oil and Gas Industry

Wind Energy


In the machine tool industry, 85% of the machine tool transmission system adopts hydraulic transmission and control. Such as grinding machine, milling machine, planer, broaching machine, press, shearing machine, combination machine and other processing equipment.

In metallurgical industry, hydraulic technology is applied to electric furnace control system, rolling mill control system, open hearth charging, converter control, blast furnace control, strip deviation and constant tension device, etc.

In construction machinery, hydraulic drive is widely used in excavators, tire loaders, truck cranes, crawler bulldozers, tire cranes, self-propelled scrapers, graders, vibratory rollers, etc.

In agricultural machinery, hydraulic technology has also been widely used, such as combine harvester, tractor and plough.

In the automotive industry, hydraulic technology is applied to hydraulic off-road vehicles, hydraulic dump trucks, hydraulic aerial vehicles and fire trucks.

In the light textile industry, hydraulic technology is applied to plastic injection molding machine, rubber curing machine, paper machine, printing machine and textile machine.

Rolling mill, caster hydraulic system and various lubrication equipment.

petrochemical industries

Electronics and pharmaceuticals

Railway internal combustion engine and generator

Thermal and nuclear power

Automatic operation and control of various process combinations, high response and precise control


Straining is using a 200-mesh (74 µm) or courser screen to keep solid contaminants out of the pump. Anything finer than that—especially when the element is something other than a screen—we consider filtering. A strainer is sometimes used on the suction side of pump, A filter should to be installed in the pressure line, the return line, and the filler-breather port or tank breather.

The difference is:

1) The main difference is in resistance. Strainers normally present low resistance to liquid flow. The pressure drop across most strainers is relatively small compared with the pressure drop across thick media filters or membrane filters.

2)Another difference is the function. A strainer is used to protect other downstream equipment (e.g., pumps, instrumentation) from damage by rogue junk. A filter is employed to separate particles from the fluid. So the strainers are a type of filter.

3)And some filters operate under vacuum (behind the filter) rather than high pressure in front of the filter,  The adjacent pump suction provides that vacuum. Filters are employed where they are needed. All filters are not close to the pumps.

Filter media is the actual material used to capture the pollution in a filter element. Whatever media is used, it usually starts out in sheet form and is then folded or pleated to expose more surface area to oil flow. This is done to increase pollution carrying capacity and to reduce pressure differential across the filter.

Hydraulic oil filters come in a variety of materials: wire mesh, stainless steel, microglass(fibreglass composites ), paper, cellulose and other synthetic materials. They may have multiple layers and different backings to meet predetermined performance criteria. Depending on their materials and construction, they may be able to capture surface and/or depth contamination.

Filters are checked by the filter cross reference.For one hydraulic filter, the hydraulic filter cross is different by different engineer manufacturer.Tamfiney Filter has whole cross reference no. For each filter,4448402’s cross reference no. Is as follows:

WIX: WL10002, SL10002

DONALDSON: P502270, J8630773

HITACHI: 4656522, 4443773, 4448402, 71423013, 4683331  


Fleetguard: HF7691,  

Mann: 6781955100, HD16190X,




SUNWARD: 730401000068, 60980004262

Hydraulic oil must be filtered by many steps of hydraulic filters.For example, suction strainer, return filter, transmission filter and other pressure filters. Hydraulic strainers can prevent the filling of a pump’s chambers, reducing its effectiveness and efficiency. This can become a problem when the strainers get clogged, and a common culprit is grease. If grease finds its way into the hydraulic fluid, it will eventually disintegrate and cause minimal problems at most. However, if it encounters a strainer or the hydraulic filters on its path through the system, there will be nothing. If it clogs the strainer, starve the pump, and cause severe issues with cavitation. If enough pressure builds up, the filters can fail and introduce steel mesh particles into the hydraulic fluid. That type of damage can quickly reach catastrophic levels.