DF Sales&Marketing
Oil Tech Moderator
States of coexistence
water can exist in oil in three states or phases. The first state, known as dissolved water, is characterized by individual water molecules dispersed throughout the oil. Dissolved water in a lubricating oil is comparable to moisture in the air on a humid day - we know the water is there, but because it is dispersed molecule-by-molecule, it is too small to see. For this reason, an oil can contain a significant concentration of dissolved water with no visible indication of its presence. Most industrial oils such as hydraulic fluids, turbine oils, etc., can hold as much as 200 to 600 ppm of water (0.02 to 0.06 percent) in the dissolved state depending on the temperature and age of the oil, with aged oils capable of holding three to four times more water in the dissolved state than new oil.
Once the amount of water has exceeded the maximum level for it to remain dissolved, the oil is saturated. At this point, the water is suspended in the oil in microscopic droplets known as an emulsion. This is similar to the formation of fog on a cool, spring day. In this case, the amount of moisture in the air exceeds the saturation point, resulting in a suspension of small droplets of moisture or fog. In a lubricating oil, this “fog” is often referred to as haze with the oil said to be cloudy or hazy.
The addition of more water to an emulsified oil/water mixture will lead to a separation of the two phases producing a layer of free water as well as free and/or emulsified oil. This is like rain falling when the amount of moisture in the air becomes excessive. For mineral oils and pao synthetics whose specific gravity is less than 1.0, this free water layer is found on the bottom of tanks and sumps.
The effects of water contamination
in a lubricating system, the two most harmful phases are free and emulsified water. In journal bearings for example, the incompressibility of water relative to oil can result in a loss of the hydrodynamic oil film that in turn leads to excessive wear. As little as one percent water in oil can reduce the life expectancy of a journal bearing by as much as 90 percent. For rolling element bearings, the situation is even worse. Not only will water destroy the oil film strength, but both free and emulsified water under the extreme temperatures and pressures generated in the load zone of a rolling element bearing can result in instantaneous flash-vaporization causing erosive wear to occur.
Under certain conditions, water molecules can be ripped up into their constituent oxygen and hydrogen atoms as a result of the high pressures generated in the load zone of a rolling element bearing. Due to their relatively small size, the hydrogen ions produced by this process can absorb onto the surface of the bearing raceway resulting in a phenomenon known as hydrogen embrittlement. Hydrogen embrittlement is caused by a change in subsurface bearing metallurgy. This change causes the bearing material to become weak or brittle and prone to cracking beneath the surface of the raceway. When these subsurface cracks spread to the surface, the result can lead to pitting and spalls.
Because the effects of free and emulsified water are more harmful compared to dissolved water, a general rule of thumb is to ensure that moisture levels remain well below the saturation point. For most in-service oils this means 100 to 300 ppm or less depending on the oil type and temperature. However, even at these levels, a significant amount of damage can still occur. Generally speaking, there is no such thing as too little water and every reasonable effort should be made to keep water contamination as low as possible.
The effects of water on a lubricant
not only does water have a direct harmful affect on machine components, but it also plays a direct role in the aging rate of lubricating oils. The presence of water in a lubricating oil can cause the progress of oxidation to increase tenfold, resulting in premature aging of the oil, particularly in the presence of catalytic metals such as copper, lead and tin in addition, certain types of synthetic oils such as phosphate esters and dibasic esters are known to react with water, resulting in the destruction of the base stock and the formation of acids.
It is not just the base oil that can be affected by moisture contamination. Certain additives such as sulfurous aw and ep type additives and phenolic antioxidants are readily hydrolyzed by water, resulting in both additive mortality and the formation of acidic by-products. These acidic by-products can then cause corrosive wear, particularly in components containing soft metals such as babbitt used with journal bearings and bronze and brass components. Other additives such as demulsifying agents, dispersants, detergents and rust inhibitors can be washed away by excessive moisture. This results in sludge and sediment buildup, filter plugging and poor oil/water demulsibility.
Water is a major cause of lubricant failure, component failure and poor machine reliability. Like all contaminants, it is important not only to recognize its presence, but also to take steps to control or eliminate the source of water ingression. If possible, water levels in all equipment should be kept below the saturation limit, with every effort made to keep moisture levels as low as possible. Whether you choose to install desiccant style breathers, improve seals, or to use a centrifugal filter or a large vacuum dehydration unit, reducing the level of water in all types of equipment can dramatically extend the life of the lubricant and the machine.
How do swepco gear oils help?
Reference is given to 201, 203, 210 & 212 swepco gear oils.
With regard to water contamination as well as other areas of concern in gear oil applications; the superiority which swepco provides comes from the most advanced chemistry available. Swepco starts with the finest base stocks which deliver superior low temperature flowability, high temperature stability and resistance to shear. They have a naturally high film strength which means superior lubrication. And their excellent resistance to oxidation means they just simply do the job longer.
Swepco’s lubium® automatically plates critical wear areas with a second safety film of solid lubrication in high temperature-extreme conditions. This prevents metal to metal contact even if the base lubricant gets forced from between the gear teeth or bearing surfaces. The lubium® also enhances the naturally superior high temperature oxidation resistance of the base stocks.
Superior anti-wear agents and friction modifiers provide additional protection from wear under high temperature, extreme pressure service. The remainder of the additive package has been carefully selected to assure optimum performance and well balanced protection. Resistance to rust, corrosion, water emulsification and foaming are all enhanced. And a special anti-squawk/anti-chatter additive is included to assure trouble free performance with limited slip differentials.
Since water contamination is the topic of this newsletter, then the subject of water emulsification and demulsification are brought to point; swepco’s gear oils will handle water contamination in an excellent manner. Water does not emulsify with their gear oils because of the outstanding ability to keep it demulsified.
Not only that, any metal part such as gears or bearings which are in a gearbox which has these oils in service and has an extraordinary amount of water in them will still have a coating of gear oil even if it is underwater! It has been noted that a piece of heavy equipment with swepco gear oil in the “box,” after being submerged for over a year still came out clean and protected with no sign of rust or corrosion….that is protection to the highest degree!
A simple test of taking a baby food jar (or an equivalent size) and a large paper clip, drop the paper clip in the empty jar, then fill the jar about half way with a swepco gear oil, then almost fill it completely to the top with water (leaving a little room between the level of the fluid and the lid). Put the lid on tight and shake the jar vigorously, when you set it down you will almost immediately see that as the water and gear oil separates, that the paper clip on the bottom of the liquid (which is water) will be completely coated with the gear oil on it!
water can exist in oil in three states or phases. The first state, known as dissolved water, is characterized by individual water molecules dispersed throughout the oil. Dissolved water in a lubricating oil is comparable to moisture in the air on a humid day - we know the water is there, but because it is dispersed molecule-by-molecule, it is too small to see. For this reason, an oil can contain a significant concentration of dissolved water with no visible indication of its presence. Most industrial oils such as hydraulic fluids, turbine oils, etc., can hold as much as 200 to 600 ppm of water (0.02 to 0.06 percent) in the dissolved state depending on the temperature and age of the oil, with aged oils capable of holding three to four times more water in the dissolved state than new oil.
Once the amount of water has exceeded the maximum level for it to remain dissolved, the oil is saturated. At this point, the water is suspended in the oil in microscopic droplets known as an emulsion. This is similar to the formation of fog on a cool, spring day. In this case, the amount of moisture in the air exceeds the saturation point, resulting in a suspension of small droplets of moisture or fog. In a lubricating oil, this “fog” is often referred to as haze with the oil said to be cloudy or hazy.
The addition of more water to an emulsified oil/water mixture will lead to a separation of the two phases producing a layer of free water as well as free and/or emulsified oil. This is like rain falling when the amount of moisture in the air becomes excessive. For mineral oils and pao synthetics whose specific gravity is less than 1.0, this free water layer is found on the bottom of tanks and sumps.
The effects of water contamination
in a lubricating system, the two most harmful phases are free and emulsified water. In journal bearings for example, the incompressibility of water relative to oil can result in a loss of the hydrodynamic oil film that in turn leads to excessive wear. As little as one percent water in oil can reduce the life expectancy of a journal bearing by as much as 90 percent. For rolling element bearings, the situation is even worse. Not only will water destroy the oil film strength, but both free and emulsified water under the extreme temperatures and pressures generated in the load zone of a rolling element bearing can result in instantaneous flash-vaporization causing erosive wear to occur.
Under certain conditions, water molecules can be ripped up into their constituent oxygen and hydrogen atoms as a result of the high pressures generated in the load zone of a rolling element bearing. Due to their relatively small size, the hydrogen ions produced by this process can absorb onto the surface of the bearing raceway resulting in a phenomenon known as hydrogen embrittlement. Hydrogen embrittlement is caused by a change in subsurface bearing metallurgy. This change causes the bearing material to become weak or brittle and prone to cracking beneath the surface of the raceway. When these subsurface cracks spread to the surface, the result can lead to pitting and spalls.
Because the effects of free and emulsified water are more harmful compared to dissolved water, a general rule of thumb is to ensure that moisture levels remain well below the saturation point. For most in-service oils this means 100 to 300 ppm or less depending on the oil type and temperature. However, even at these levels, a significant amount of damage can still occur. Generally speaking, there is no such thing as too little water and every reasonable effort should be made to keep water contamination as low as possible.
The effects of water on a lubricant
not only does water have a direct harmful affect on machine components, but it also plays a direct role in the aging rate of lubricating oils. The presence of water in a lubricating oil can cause the progress of oxidation to increase tenfold, resulting in premature aging of the oil, particularly in the presence of catalytic metals such as copper, lead and tin in addition, certain types of synthetic oils such as phosphate esters and dibasic esters are known to react with water, resulting in the destruction of the base stock and the formation of acids.
It is not just the base oil that can be affected by moisture contamination. Certain additives such as sulfurous aw and ep type additives and phenolic antioxidants are readily hydrolyzed by water, resulting in both additive mortality and the formation of acidic by-products. These acidic by-products can then cause corrosive wear, particularly in components containing soft metals such as babbitt used with journal bearings and bronze and brass components. Other additives such as demulsifying agents, dispersants, detergents and rust inhibitors can be washed away by excessive moisture. This results in sludge and sediment buildup, filter plugging and poor oil/water demulsibility.
Water is a major cause of lubricant failure, component failure and poor machine reliability. Like all contaminants, it is important not only to recognize its presence, but also to take steps to control or eliminate the source of water ingression. If possible, water levels in all equipment should be kept below the saturation limit, with every effort made to keep moisture levels as low as possible. Whether you choose to install desiccant style breathers, improve seals, or to use a centrifugal filter or a large vacuum dehydration unit, reducing the level of water in all types of equipment can dramatically extend the life of the lubricant and the machine.
How do swepco gear oils help?
Reference is given to 201, 203, 210 & 212 swepco gear oils.
With regard to water contamination as well as other areas of concern in gear oil applications; the superiority which swepco provides comes from the most advanced chemistry available. Swepco starts with the finest base stocks which deliver superior low temperature flowability, high temperature stability and resistance to shear. They have a naturally high film strength which means superior lubrication. And their excellent resistance to oxidation means they just simply do the job longer.
Swepco’s lubium® automatically plates critical wear areas with a second safety film of solid lubrication in high temperature-extreme conditions. This prevents metal to metal contact even if the base lubricant gets forced from between the gear teeth or bearing surfaces. The lubium® also enhances the naturally superior high temperature oxidation resistance of the base stocks.
Superior anti-wear agents and friction modifiers provide additional protection from wear under high temperature, extreme pressure service. The remainder of the additive package has been carefully selected to assure optimum performance and well balanced protection. Resistance to rust, corrosion, water emulsification and foaming are all enhanced. And a special anti-squawk/anti-chatter additive is included to assure trouble free performance with limited slip differentials.
Since water contamination is the topic of this newsletter, then the subject of water emulsification and demulsification are brought to point; swepco’s gear oils will handle water contamination in an excellent manner. Water does not emulsify with their gear oils because of the outstanding ability to keep it demulsified.
Not only that, any metal part such as gears or bearings which are in a gearbox which has these oils in service and has an extraordinary amount of water in them will still have a coating of gear oil even if it is underwater! It has been noted that a piece of heavy equipment with swepco gear oil in the “box,” after being submerged for over a year still came out clean and protected with no sign of rust or corrosion….that is protection to the highest degree!
A simple test of taking a baby food jar (or an equivalent size) and a large paper clip, drop the paper clip in the empty jar, then fill the jar about half way with a swepco gear oil, then almost fill it completely to the top with water (leaving a little room between the level of the fluid and the lid). Put the lid on tight and shake the jar vigorously, when you set it down you will almost immediately see that as the water and gear oil separates, that the paper clip on the bottom of the liquid (which is water) will be completely coated with the gear oil on it!