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What is Contamination?

Contamination refers to the presence of anything in machine fluid systems, which does not belong there. Examples of contaminates include: paint flakes, rag fibres, metals, grease, weld splatter, sealing materials, dust and water.

Oil and Water

When systems are contaminated, efficiency drops, cycle times increase and component and fluid life are shortened. If contaminated fluids are left untreated, this can eventually lead to catastrophic system failure, unplanned downtime and costly repairs.

Demand for increased productivity has produced industry trends toward electro-hydraulics, higher system pressure and tighter internal clearances. As a result of these trends, today's fluid systems will not tolerate dirt and contamination. This threatens reliability throughout the life of all types of hydraulic operated machinery.

Contamination of Bulk Oil

When bulk oil is supplied to sites it no longer comes under the strict guidelines that the oil producing companies adhere to within their operations. It may change storage depots a number of times before it reaches the end user. The oil is moved from the oil producers storage tanks by sea, rail and road transport, and at each transfer point contaminants, particularly dust particles and water may enter the pipe work and tanks. New oil is not clean oil. The cost to filter the bulk oil at each of these points would be enormous and the industry feels that it would be unrealistic to undertake such a task.

How many end users of the oil products actually have the bulk oil sampled and tested before putting it into their machines, very few, therefore by installing a filter system on bulk tanks, oil drums etc. to meet the machine ISO oil cleanliness guidelines would ensure that clean oil is being added every time.

Why is water in fluid bad?

When water is present it:

  • Depletes some additives and reacts with others to form corrosive by-products which attack some metals

  • Reduces lubricant film-strength, which leaves critical surfaces vulnerable to wear and corrosion

  • Reduces filterability and clogs filters

  • Increases air entrainment ability and cause bacterial growth

  • Increases the likelihood of cavitation's occurring

Free water is free to separate and settle to the base of the reservoir. Free water is the most damaging, because it can displace lube oil and allow metal to metal contact of rotating equipment. The presence of free water needs to be monitored online effectively. Free water in oil can cause quick and costly breakdowns. It can happen so fast that in many cases, water in oil can be treated as a more serious contamination problem than metal particle contamination! Since water contamination can occur at any time. It is possible that serious damage can be caused on bearings and other lubricated component without the user knowing it is happening at the time.

Dealing with water in hydraulic fluid

Oil becomes cloudy when it is contaminated with water above its saturation level. The saturation level is the amount of water that can dissolve in the oil's molecular chemistry and is typically 200 - 300 ppm for every 1ml of oil at 68°F (20°C) for mineral oils. If hydraulic oil is cloudy it indicates that water is present. A guide to water contamination is 10,000 ppm is equivalent to 1% water in a hydraulic system so a 300 litre tank with a 1% reading would contain 3 litres of water. All oils have saturation points as they are designed to hold in suspension a small amount of water. Once saturation point is reached it becomes free water which can settle to storage tank bottoms and provide an ideal environment for bacteria to grow.

Fluid Application for Kleenoil Filtration Units

The cleanliness of your fluid is critical to the trouble free and cost effective operation of your system. Components can be very expensive and need special consideration when selecting and filtering. ISO 4406 code is a standard that is recognised in the industry. Certain recommended fluid cleanliness quantities are necessary to realise the best performances and cost saving operation of your hydraulic system.

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