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HYDRAULIC SYSTEMS POLLUTION MANAGEMENT

The importance of oil in hydraulic systems, this means a lot to pronounce, but very little is known and what it contains. Pollution is one of them, at least 75% of the cause of hydraulic system failures is because the oil is dirty, but the literature “oil breakdown” is not something he always accused the victim of pollution equipment.

Identification of the pollution caused by hydraulic systems and good analysis of the factors, it is extremely important in terms of the success of the struggle.

What is pollution and why is it important?

This identification of pollutants and the pollution of the system elements will be useful to begin by discussing what might be sensitive to.

What are the pollutants? BASICA pollutants include the following aspects.

1 –     Water and other undesirable liquids (wrong oil, etc.)

2 –     Solid particles (dust entering from outside, wear metals from)

3 –     Bacteria and mushroom formations (formations in the system is accelerated by the presence of water)

Fall outside the above mentioned pollutants and oil in the hydraulic system, even though the physical-chemical properties of the oil normally lead to the need for early replacement.

Then change the oil of the factors that led to the need to be mentioned:

1 – Viscosity

2 – TAN (Acidification): (Diesel engine oil TBN-Total Base Number).

3 – Water

4 – Particle pollution

‘Acidification’ physical properties of the base oil (oxidation, corrosion, deterjanlaşmayı, etc. in order to prevent air retention) was added in order to improve the status of the chemical additive package. New fat ’0 ‘starts and oil oksitlendikçe degree rises. Designated by the manufacturer of the oil additive package is no longer at end of life means that when it reaches a certain extent, and need to change the oil.

Viscosity and acidification are the qualities of the oil properties. Each producer of oil into base oil according to the terms of use that additional contributions to its customers by improving the properties of commercial options.

For example, oil-indexed instead of the normal viscosity ‘high viscosity indexed’ (HVI) In the case of oil temperature change of less affected by oil viscosity. Likewise, various chemical additives to be added to oil oxidation and oil to be used as long-term opportunity to give asitlenmesini slowing down the oil. To immediately evacuate the air in the oil, preventing erosion, providing the best features, such as deterjanlaşmaması these additives.

The effect of temperature

These features are features that can be controlled by the oil manufacturer. However, these characteristics of the oil will be exposed to abnormal working environment, especially the oil temperature will be affected.

The Arrhenius equation has to be mentioned here. Dutch chemist JH van ‘t Hoff In 1884, an equation describing the relationship between temperature and the chemical reaction is proposed.   In 1889 the Swedish chemist Svante Arrhenius commented on this equation to explain the chemical trials. According to the Arrhenius equation based on chemical reactions occurring at room temperature 10 ⁰ C increase in temperature of the chemical reaction rate doubles. Accordingly, the hydraulic oil temperature of 10 ⁰ C over the studied period of time than normal oil life is all we can say will fall by half.

On the other hand in the air in oil (usually the shaft side of the cylinders with air intake negative pressure is felt in the case where – seals are designed to keep pressure on the other hand can not prevent entry of air effectively) dizellenme under the influence of exposure to high pressure and temperature combustion occurs and the oil seals contamination increases.

Therefore, extreme temperature as a factor in the pollutant would be appropriate to count.

Contamination of equipment and components used in the hydraulic system according to the structure will show a different effect. Then you can say that pollution is a relative concept. Elements that determine how much of the power used by a relativistic system can tolerate pollution. With a microchip production workshop will be different due to a hydraulic assembly workshop will need cleaning. Therefore, their product is a manufacturer of machinery or equipment needed to establish a realistic level of oil cleanliness.

Determination of hydraulic systems for the cleaning target

British Fluid Power Association (The British Fluid Power Association (BFPA)   a realistic “TARGET CLEANING” following a series of factors to determine the level of identified need to be considered:

-           Operating pressure and density of service

-           Pollution sensitivity of the component

-           The cost of replacement parts

-           The cost of downtime due to failure

-           Responsibilities of security engendered by

-           Environmental conditions

1-The operating pressure and intensity of services depending on the density and pressure ranges in the following table for the weights determined by the designated service.

Service	Examples	Working Pressure (bar) Weighted Score based on
		0-60	61-160	161-250	251-400	401 +
Light	Continuous operation at or below the nominal pressure	1	1	2	3	4
Middle	Slight pressure outputs up to a maximum value of pressure	2	3	4	5	6
Heavy	Frequently change between zero and a maximum pressure	3	4	5	6	7
Severe	Sudden changes between zero and maximum pressure, high-frequency pressure to reach the peak value, ie, power presses and punching machines	4	5	6	7	8

However, contamination of equipment used in the hydraulic system    is given a score depending on how much is sensitive.

The sensitivity of 2-pollution equipment.

Sensitivity	Examples	Weight
Below Average	Low-pressure gear pumps, hand-operated valves and poppet valves	2
Average	Vane pumps, solenoid, gate valves, high pressure gear pumps	3
Above Average	Piston pumps, proportional valves	4
High	Industrial servo valves, proportional valves of high-performance	6
Extreme High	High-performance servo-valves	8

Similarly, the expected service life of equipment, resulting in replacement of equipment   cost of the machine and the cost of being out of service responsibilities, taking into account the security risks brought by scores of weight for each condition are given and as a result of all this on ratings TARGET LEVEL OF CLEANING determined.

Determining pollution sensitivity of the equipment used in the hydraulic system and is an important issue that should be taken into account. Original equipment manufacturers (OEM) oil pollution limits stipulated by the product’s technical specifications of their products (specifications) show. This limit value is the key that can eliminate the warranty for the equipment. For example Tier3 engines compliant electronic fuel injectors causing pollution problems frequently encountered when these failures are not considered under warranty.   The following table is used as a general recommendation for the equipment owned pollution limit values ​​are given:

HYDRAULIC EQUIPMENT REQUIRED FOR VARIOUS CLEANING OIL LEVEL
	Standard		100ml’deki the number of particles
Equipment	NAS	ISO	5-15μ particle numbers in the range	> 15μ particle counts on
Servo Control Valleri	5-6	14/11	8000-16000	1000-2000
Vane and piston pumps / motors	7-8	16/13	32000-64000	4000-8000
Directional and Pressure Control Valves	7-8	16/13	32000-64000	4000-8000
Gear Pumps / Motors	9	17/14	4000-130000	8000-16000
Flow Control Valves, Cylinders	10	18/15	130000-250000	16000-32000

In this case, a hydraulic gear pump, running on the system used in the cleaning needs of the oil pump and the servo valve with a piston in a hydraulic system that uses the cleaning needs will be different. In other words, gear pump, piston pump, compared to a system that uses a stage show more tolerance for dirty oil.

In short, ISO and NAS Standards

The level of pollution caused by oil in the particles is determined mainly by the standards of ISO4406 and NAS1638. Specific particle size of the requested standard required by the particle counting devices ararlıklarında determine the degree of pollution by counting the particles per 100 ml of oil. Havacılı U.S. National Standard (National Aerospace Standard), the NAS system with 5-15μ, 15-25μ, 25-50μ, 50-100μ, and> 100μ size intervals, which makes the count of particles. NAS standard practice officially lifted in 2001, but (instead of the standard was APC4059) is still used to determine the level of pollution kompone.

ISO4406: Previously> 5 μ ‘s and> 15 μ from the larger particles, while taking into account the latest revisions of pollution level counts as a 3-stage re-arranged to count. ISO4406 standard 100 ml of sample 17/14 encoding, the number of 17 large oil 5 microns, 14 count which corresponds to a large number of particles is 15 microns show code. ISO4406 standard, as it is now a new particle counts> 4 μ,> 6 μ, and> 14 μ to be carried out in 3 stages. For example, 19/16/13 code 4 microns large number of particles 19, 6 and 14 microns to 16 microns large number of particles corresponding to the large number of particles up to code, show that the number 13.

THIS levels of pollution as an example of how a difference in our NAS4 and two oil samples under a microscope view of the level of pollution NAS12 are shown below. These particles can be seen under a microscope, but over time, wear and tıkanmalarla affects performance in hydraulic systems, and increasingly sensitive and expensive parts, and even change takes place on the revision.

The invisible enemy

Creating a risk for small particles of micron particles due to the machine by entering the moving parts of the dynamic gaps to give rise to wear around here.

The following examples are all crucial to the operation of hydraulic equipment, hydraulic system and maintenance-repair-switching costs are very high. For example, piston pumps (medium-sized excavators) repair prices ranged from £ 25.000 to £ 4,000. In the event of change of the control valve body wear channels are required. Control valves gate valves (with notch geometry) is not changed between the start-off custom designed and each other. Proportional valves under dynamic operating spaces 6 microns. Machining tolerances were so tight that some of the hydraulic equipment, must be removed, then cooled again to takılabilmeleri. Micronic circuits can easily block the pollution control orifices and cause service interruptions. Not seen as a major fault in the detention of the machine from service, disassembled and cleaned to install and requires adjustment of the intervention of none service element and a service in itself creates a loss and cost.

Microns on the ease of detection in our daily lives that they account for what is worth örneklemekte:

The following examples of equipment used in the hydraulic systems for the micron (μ) mertebesindeki pollution, given the gaps in the dynamic between moving parts, clearly shows how much may create serious problems.

Relationship with the machine-pollution equipment and oil life

Keeping pollution under control for the owner of the machine, as well as many other benefits, the utility of 2 important mention appear:

1 –     Machinery and equipment life extension

2 –     Oil life extension

1-contaminated oil shortens the life of the machine

In fact, diesel engines, this relationship has been considered an issue very clearly understood. Rapid wear of engine bearings and engine waste oil into the causes of early revision. Segments of the suction motor and the cylinder more quickly erodes the presence of dust in the mood.

However, the real power in the system to easily kabullenilmez parts working. The simplest measure even the replacement of contaminated oil in many applications are made ​​in accordance with manufacturer’s recommendations. Working conditions is not different from the diesel engine, hydraulic systems, we can say that even more severe conditions. The heart of the machine, and if all that had worked the pump, engine returns to the same periods as the tight tolerances to ensure sealing and hydraulic parts working. Directional control valves, proportional valves, pilot controls the circuit consists of moving parts that cuts off all oil ways, so moving between the two metal sealing surface should be provided. But the precision of 10 microns are invisible to the enemy, and the OEM filter capable of filtering elements tutamadığı 2-10 micron particles enter into this dynamic space and over time lead to wear. This service also shorten the life span of these parts.

Linked with the life of the oil cleaning machine

117 British Hydromechanics Research Association in 8 different categories of power on the machine by following the cleaning of oil as a result of his 3-year-long experimental research with the machine / equipment service life is determined between the following relationship. Accordingly, the engine / hydraulic machinery and equipment, the cleaning of oil, depending on level of improvement in cleaning machinery / equipment life, which shows that a considerable strain. As an example, the order of 21/18 employees exposed to an oil pollution, oil cleaning machine 18/15 to improve the rank of a 2-fold prolongation of the life of the machine indicates.

Hydraulic systems for at least 75% of the studies of the faults that lays out the oil pollution. Kirliliğindendir 80% of the oil pump failure.

According to Caterpillar company, “the number one cause of dust and pollution hydraulic system failures.” When the filtered oil in a thin hydraulic system life can be extended up to 50x.

According to research firm AC Delco Division of General Motors, “40-micron filter, engine wear by 50% reduced compared to the use of 30 micron filter. In the same way the use of 15 micron filter reduced the wear rate of 75%. “Sürtünmedeki Research as well as the resulting reduction in fuel economy is providing a 5% showed up. (1,2)

Nippon Steel, Kawasaki Steel, the U.S. Navy, Oklahoma State University, MIT, similar research conducted by the improvement of the oil cleaning machine / kompone growth rates resulted in a very serious life revealed.

Commissioned by the U.S. Department of Energy’s Idaho National Laboratories under the supervision of more than 3 years of experimental research, the vehicle fleet diesel engine oil, engine oil as a result of the implementation of the by-pass filter on the prolongation of life was 90% (3).

However, a generally accepted detection, hydraulic systems, the cost of removal of pollutants entering, 5 times more expensive than the cost to prevent dirt from entering. Clean dirt from entering the hydraulic system, but the system of partial circuits of the machine washing (flushing) and can be achieved. This is done by passing the expertise and labor-intensive, start off the process is difficult.

2 – extends the life of the oil to keep the oil clean

Of course, each oil has a limited service life. As mentioned in the article in the early life determinants of fat

1 – Viscosity

2 – TAN (Acidification): (Diesel engine oil TBN-Total Base Number).

3 – Water

4 – Particle pollution.

Any of these features is impaired when the decision will cause the oil change. The point to be underlined here, viscosity and TAN (or diesel engines, TBN) oil physical / chemical properties related to particle pollution, while an element into the system from the outside.

In other words, a manufacturer of oil viscosity, TAN value is out of bounds and saw a deterioration in “OIL CHANGE” gives instructions, but the increase in pollution will never be accepted as the cause of the lab, OIL CHANGE. This is because the physical and chemical properties of the oil is normal, and particle pollution is a defect can be corrected. So the oil lab “… oil in the normal case, but the filter needs to be better” to have a recommendation.

Therefore, to keep pollution under control of the oil to be used until it reaches the limit values ​​of physical and chemical properties enables.

REASON FOR CHANGE OIL particle pollution as the oil producer but which will require the manufacturer of the machine. This is because the equipment is allowed by the above-described hydraulic system BORDER POLLUTION. Many machinery manufacturers warranty period of the oil pollution in the client machine to analyze the moves by taking samples periodically and if necessary because of the warranty for the exchange of oil will go a earlier time. The contamination of the oil with the lack of care and attention (careless and incorrect replenishment of the oil, a heavy hammer to use, sealing of the tank ventilation is inadequate, corruption or maintenances, hydraulic seals, etc. to keep the connections open for reasons), maintenance and oil changes can not be carried in time earlier than the oil pollution and earlier may also make the necessary changes.

Here, oil life is more important factors, to talk about the need to provide a fundamental artırılabilmesini: namely, that the OEM filter elements used on the machine fails to filtration because the oil in the fine particles under 10 microns can not be held by the filter. After a while it accumulates in the low-micron particles to exceed the limit level. After all OEM filter particles over 10 microns in the laboratory analysis results as completely temizlese echelon of particle pollution based on the value of the dirtiest oil in this pollution, the value is determined as a grade of pollution. Micron particle size of the oil counts for the counting had said certain steps. Here’s the tiers at the bottom of the natural size of 10 microns in excess of the limit of the first ones, ie, 4 and 6 microns large, 10 micron and smaller ones) will be.

Here is the hydraulic oil, which will lengthen the life of the oil accumulation in these six additional filtration measures 10 microns (2-3 microns süzebilen filter systems) cleanup by filtration. Research and field trials in süzülebilmesi the normal order of 2-3 micron hydraulic oil of an oil vasıflardaki 5000 to 8000 hours has shown is available.

A similar type of work Hidromek firm HMK220LC ekskavatörünün hydraulic system with 2 micron by-pass filter implementation of the quality of the trials of the oil ISO VG46 is the order of 5000 hours to fill out, and laboratory analysis, despite the NAS8 cleaning as the oil viscosity and acidification has been found to be available. The above mentioned analysis, the system worked, and then returned to boom ahead of the filter were taken with an oil sample (only the last 400 hours worked as a hammer).

Pollution management requires a systems approach

Trend in the fight against pollution generally, has always been to focus only on the hydraulic system. However, the necessary measures to eliminate pollution and pollution and ways to login to the system and the attitudes of a management process in the fight against pollution appears to be taken into account. Pollution management, just as the built-in Quality Management System procedures and control mechanisms need and the process starts from the top: the fight against pollution that oil changes or maintenance and repair workers is the responsibility of many government, because it is usually due to creation of the management system and processes, as well as the size of the investment are also present.

Hydraulic system entry points and the dirt needs to be done around here are as follows.

The entry point	Status
Status of the oil purchased at the entrance:	Barrels of new oil that is not clean (NAS10, or 11), and the machine must be placed by at least 3 micron filter. Using an open container or tank must not be loaded directly.
Storage of the oil:	Oil drums / containers in the open air and should not be as steep. Due to the difference between night and day sızaklık nefeslenir containers and closures of this oil, dust and causes water to enter. Lids should not be open. Oil pumping unit should be filled with a closed filtration.
Storage and warehousing of parts:	Hydraulic components are stored in the barn (especially filters, o-rings, gaskets, couplings and fittings) should not be left exposed, container and stored in a clean environment.
Installation-Maintenance-Repair phase:	Hydraulic connection to the closure plugs and ports are open and held promptly, worked to keep the area clean, vacuum cleaning should be carried instead of compressed air, dirty parts or cleaning agent used.
Suitable environmental conditions of behavior:	Working in dusty environments or machines used to break the maintenance periods, oil changes and filter element if necessary, be kept shorter.
Manufacturers’ recommendations to be considered:	Used in the assembly and maintenance on the machine manufacturer’s recommendations should be followed aksamın

All of these points become the mandatory introduction of control processes requires a management system. The performance of the business of the oil sample analysis, and given the periodic monitoring of trends in environmental conditions, pollution, the problems it is important to predict the terms.

Some thoughts and misconceptions:

Some machines will eliminate the concerns of the users may think of pollution practices specified in the following examples. Disadvantages of these ideas are listed below.

“In my opinion …”	Have you thought about them as well?
Winterized I change periodically, this is sufficient:	The machine in a tank of hydraulic oil is changed, but up to 35% with 25% of the total oil in an oil installation (cylinders, hoses, pipes) remains, the oil is already enough new oil kirletmeye.
The new oil is not clean:	Varin is not clear from the oil. Measurements at the level where the new oil was NAS10 or 11. This is already a border oil pollution. New oil is never being subject to additional filtration and tin never be poured directly into the tank. This coupled with the remaining oil to the oil installations start with a dirty oil will start the service.
I use high-skilled oil, this oil will extend the life:	This does not eliminate the need to combat pollution. Even the most excellent oil contaminants from the environment if not kept under control as soon as possible NAS9-10 above the level of analysis is that the value provided by the manufacturers of machinery and equipment over the pollution.
I’m doing fine filter with care units off-line filtering, this is not enough:	This periodic maintenances oil cleans corrosive effects of pollution in the process of normal operation of machine components, but the protection will be more healthy. Mechanical service life and extended oil life, but always with a pollution control can be achieved.
Change the time of making timely maintenance of the machine and the OEM filter elements: a filter removes dirt	OEM filters perform filtering on the machine, but the order of 10 microns. Pollutants that pose a threat to the machine hydraulic equipment pollutants under 10 microns. OEM filters in the filter becomes clogged with unfiltered oil to by-pass system to switch leads.

Everyone’s a win-win game for the fight against pollution

The following contributions will provide a better management of the fight against pollution

-           That high costs will be reduced machine downtimes for Business

-           Eroded because of the cost of equipment to minimize pollution of change incecektir

-           Oil life will be prolonged

-           Warming will be reduced and unnecessary wear of hydraulic system will be prevented

-           Unnecessary power loss will be prevented

-           Customer satisfaction will

-           Warranty claims will reduce the

-           Manufacturer’s sales will increase the prestige and future

The fight against pollution must be taken seriously. This is a management responsibility and a good return on investment of all kinds are in the implementation. So POLLUTION MANAGEMENT SELF PAYING BACK THE EASY TO AN INVESTMENT.

Text Lightning

Mechanical engineer

References:

1 – ( http://www.maintenanceresources.com/referencelibrary/oilanalysis/oa-pm.htm )

2 – ( http://www.megatrol.com/main/email/MegatrolMessenger-v1i2.htm )

3 – http://avt.inl.gov/pdf/oilbypass/oilbypassfinalreport.pdf