DF Sales&Marketing
Oil Tech Moderator
three types of friction
Q: there are three types of friction. What are they?
A: sliding friction, rolling friction, combination friction.
common grease ingredients
Q: name four common soap-based thickeners used in greases.
A: lithium, calcium, sodium, aluminum
issues with over-lubricated bearings
Q: what problems can occur when a bearing is lubricated with too much oil or grease?
A: higher energy consumption with oil/grease operating temperature, short lubricant life, thinning oil film thickness.
lubricant additive controls gear wear
Q: what type of wear in gears and bearings is controlled by using ep (anti-scuff) additives?
A: adhesive wear.
determining gearbox oil levels
Q: I have gearboxes with the round bull’s-eye type sight glass. What is the proper oil level in this type of sight glass?
A: this initially sounds like a question with an obvious answer. But the question arises, should the oil be visible when the oil is hot or cold and whether the machine is operating or shutdown? With round bull’s eye sight glasses, it is generally the oem’s intent that the oil should be in the middle of the sight glass when the unit is idle (not operating) and the oil is at ambient (room) temperature. Vertical sight glasses should be marked with high and low level marks and be clear whether the oem in- tends these marks to be used when the machine is hot or at ambient temperature. This is often not done, but the level marks are generally intended for an idle, room-temperature machine. In all cases, be sure that the sight glass has not become stained by the oil and that the vertical sight glass air vent is not blocked. Both of these conditions have been responsible for catastrophic equipment failures.
water devastates bearings
Q: after seeing the same bearing fail several times, we performed an oil analysis. The results appeared normal, but there was a small amount of water content. The oil doesn’t appear to have water in it. Could this be the problem?
A: moisture in lubricating oils can have a devastating impact on component lifecycles. According to a major bearing supplier, it is possible to shorten the life of rolling element bearings by as much as 75 percent without ever knowing that moisture is in the oil, based on visual observation. Water causes oxidation, acid formation, varnishing, sludging, foaming, viscosity problems (water firs thickens and then thins the oil) and can cause an oil to become conductive. Water also creates conditions for corrosion to dramatically increase. Water can be driven off oil by maintaining the right temperature, and through the use of absorbent media filters and vacuum dehydration. Industrial equipment that is frequently turned on and off is most susceptible to moisture from the atmosphere, particularly during the summer months when atmospheric moisture is at its peak.
why lubricants degrade
Q: what are the main factors that promote chemical degradation of lubricants?
A: air (oxygen), elevated temperatures, metals, and water.
how to detect oil oxidation
Q: what are common indications of oil oxidation that are observed with the human senses?
A: sludge/varnish formation, oil darkening, acids and putrid oil odor.
six tasks for engine oil to accomplish
Name the six tasks of engine oils.
1) reduce friction and wear—lubricate 2) carry away heat 3) disperse contaminants 4) protect against rust and corrosion 5) control deposit formation 6) resist the attempts of heat and oxygen to change its properties
reasons for finding calcium in engine oil
Q: what is the most common reason for finding calcium in engine crankcase oils? To what parameter might this relate?
A: detergent additive (calcium sulfonate). Bn (tbn) base number.
what to inspect during an oil drain
Q: what inspection needs to be performed when draining oil from a sump or reservoir?
A: the presence of bottom sediment and sludge.
viscosity index of mineral oils
Q: mineral oils cannot have a viscosity index higher than 100. True or false?
A: false. Highly refined mineral oils May have vi as high as 130.
important hydraulic fluid properties
Q: besides viscosity, what are other important properties of hydraulic fluids?
A: water separability, air-release, resistance to foaming, rust protection, anti-wear protection, viscosity index, oxidation resistance, thermal stability.
Lubricants can thermally degrade for a variety of reasons and causes. Unlike oxidation, thermal failure can occur in new lubricants with healthy additive packages. However, many of the symptoms of oxidation are also symptoms of thermal degradation.
One of the most common causes of thermal failure in hydraulic fluids and some lubricating oils relates to aeration, I.e., entrained air bubbles. These bubbles can become rapidly compressed in hydraulic pumps and in the squeeze zones of bearings. This results in high localized temperatures. Hot surface carbonization is another form of thermal failure. When an oil thermally degrades, problems associated with sludge, varnish, deposits, viscosity change, and additive decomposition will often occur.
will synthetics always last longer?
A: since synthetic oils get contaminated with wear metals, carbon soot, combustion residue, and by-products of fuels, such as acids and sulfur compounds, in much the same way as petroleum oils, it May be unreasonable to expect synthetic oils to last longer than petroleum base lubricants.
Oil levels must be checked periodically, filters serviced or replaced on a regular basis and above all, oil samples should be taken regularly and sent to a competent used oil analysis laboratory for analysis.
synthetics prone to hydrolysis
Q: what types of synthetics are at risk for water-induced degradation called hydrolysis?
A: esters such as phosphate ester, polyol ester, dibasic acid ester.
distinguishing synthetic gear oil from other oils
Q: “relating to gear boxes on trucks, if the owner or the driver doesn’t know if the gear lubes are synthetic, is there a fool-proof way to determine this without having to send a sample to the lab? Some oil manufacturers color their synthetic oils, while others don’t. What would happen if the oils were to be mixed or topped off with the wrong oil?”
a: the color of the lube, as I’m sure you are aware, is simply a dye. There are no standards, and manufacturers can and do change colors whenever they please. Unfortunately, there is no reliable way of differentiating between mineral and synthetic in the field. However, because synthetic base oils are white (meaning transparent) as compared to a mineral oil which has a darker natural color, this May be a distinguishing factor. Note, however, that despite the fact that the base oil of a synthetic is white, the additives can add considerable color to the finished oil.
In the laboratory, you could distinguish synthetics from mineral oil by looking at a combination of physical properties including vi, flash point, pour point, and aniline point (all standard astm tests). There May also be different elemental additive chemistry.
In the type of application you are talking about, the synthetic gear oil will likely be polyalphaolefin (pao) based. Paos are chemically similar to mineral oils and hence mixing the two should not cause a compatibility problem (especially if both oils are the same api classification). Although, if a synthetic is required, for example cold temperature operation, using a mineral by mistake May cause other problems like stiff shifting in a manual transmission.
Also be aware that in industrial applications, some synthetic gear oils are polyglycol (pag) basestocks, which are chemically incompatible with both pao synthetics and mineral oils. In this case, mixing will result in serious incompatibility issues.
Dick floryanowich
swepco
Q: there are three types of friction. What are they?
A: sliding friction, rolling friction, combination friction.
common grease ingredients
Q: name four common soap-based thickeners used in greases.
A: lithium, calcium, sodium, aluminum
issues with over-lubricated bearings
Q: what problems can occur when a bearing is lubricated with too much oil or grease?
A: higher energy consumption with oil/grease operating temperature, short lubricant life, thinning oil film thickness.
lubricant additive controls gear wear
Q: what type of wear in gears and bearings is controlled by using ep (anti-scuff) additives?
A: adhesive wear.
determining gearbox oil levels
Q: I have gearboxes with the round bull’s-eye type sight glass. What is the proper oil level in this type of sight glass?
A: this initially sounds like a question with an obvious answer. But the question arises, should the oil be visible when the oil is hot or cold and whether the machine is operating or shutdown? With round bull’s eye sight glasses, it is generally the oem’s intent that the oil should be in the middle of the sight glass when the unit is idle (not operating) and the oil is at ambient (room) temperature. Vertical sight glasses should be marked with high and low level marks and be clear whether the oem in- tends these marks to be used when the machine is hot or at ambient temperature. This is often not done, but the level marks are generally intended for an idle, room-temperature machine. In all cases, be sure that the sight glass has not become stained by the oil and that the vertical sight glass air vent is not blocked. Both of these conditions have been responsible for catastrophic equipment failures.
water devastates bearings
Q: after seeing the same bearing fail several times, we performed an oil analysis. The results appeared normal, but there was a small amount of water content. The oil doesn’t appear to have water in it. Could this be the problem?
A: moisture in lubricating oils can have a devastating impact on component lifecycles. According to a major bearing supplier, it is possible to shorten the life of rolling element bearings by as much as 75 percent without ever knowing that moisture is in the oil, based on visual observation. Water causes oxidation, acid formation, varnishing, sludging, foaming, viscosity problems (water firs thickens and then thins the oil) and can cause an oil to become conductive. Water also creates conditions for corrosion to dramatically increase. Water can be driven off oil by maintaining the right temperature, and through the use of absorbent media filters and vacuum dehydration. Industrial equipment that is frequently turned on and off is most susceptible to moisture from the atmosphere, particularly during the summer months when atmospheric moisture is at its peak.
why lubricants degrade
Q: what are the main factors that promote chemical degradation of lubricants?
A: air (oxygen), elevated temperatures, metals, and water.
how to detect oil oxidation
Q: what are common indications of oil oxidation that are observed with the human senses?
A: sludge/varnish formation, oil darkening, acids and putrid oil odor.
six tasks for engine oil to accomplish
Name the six tasks of engine oils.
1) reduce friction and wear—lubricate 2) carry away heat 3) disperse contaminants 4) protect against rust and corrosion 5) control deposit formation 6) resist the attempts of heat and oxygen to change its properties
reasons for finding calcium in engine oil
Q: what is the most common reason for finding calcium in engine crankcase oils? To what parameter might this relate?
A: detergent additive (calcium sulfonate). Bn (tbn) base number.
what to inspect during an oil drain
Q: what inspection needs to be performed when draining oil from a sump or reservoir?
A: the presence of bottom sediment and sludge.
viscosity index of mineral oils
Q: mineral oils cannot have a viscosity index higher than 100. True or false?
A: false. Highly refined mineral oils May have vi as high as 130.
important hydraulic fluid properties
Q: besides viscosity, what are other important properties of hydraulic fluids?
A: water separability, air-release, resistance to foaming, rust protection, anti-wear protection, viscosity index, oxidation resistance, thermal stability.
Lubricants can thermally degrade for a variety of reasons and causes. Unlike oxidation, thermal failure can occur in new lubricants with healthy additive packages. However, many of the symptoms of oxidation are also symptoms of thermal degradation.
One of the most common causes of thermal failure in hydraulic fluids and some lubricating oils relates to aeration, I.e., entrained air bubbles. These bubbles can become rapidly compressed in hydraulic pumps and in the squeeze zones of bearings. This results in high localized temperatures. Hot surface carbonization is another form of thermal failure. When an oil thermally degrades, problems associated with sludge, varnish, deposits, viscosity change, and additive decomposition will often occur.
will synthetics always last longer?
A: since synthetic oils get contaminated with wear metals, carbon soot, combustion residue, and by-products of fuels, such as acids and sulfur compounds, in much the same way as petroleum oils, it May be unreasonable to expect synthetic oils to last longer than petroleum base lubricants.
Oil levels must be checked periodically, filters serviced or replaced on a regular basis and above all, oil samples should be taken regularly and sent to a competent used oil analysis laboratory for analysis.
synthetics prone to hydrolysis
Q: what types of synthetics are at risk for water-induced degradation called hydrolysis?
A: esters such as phosphate ester, polyol ester, dibasic acid ester.
distinguishing synthetic gear oil from other oils
Q: “relating to gear boxes on trucks, if the owner or the driver doesn’t know if the gear lubes are synthetic, is there a fool-proof way to determine this without having to send a sample to the lab? Some oil manufacturers color their synthetic oils, while others don’t. What would happen if the oils were to be mixed or topped off with the wrong oil?”
a: the color of the lube, as I’m sure you are aware, is simply a dye. There are no standards, and manufacturers can and do change colors whenever they please. Unfortunately, there is no reliable way of differentiating between mineral and synthetic in the field. However, because synthetic base oils are white (meaning transparent) as compared to a mineral oil which has a darker natural color, this May be a distinguishing factor. Note, however, that despite the fact that the base oil of a synthetic is white, the additives can add considerable color to the finished oil.
In the laboratory, you could distinguish synthetics from mineral oil by looking at a combination of physical properties including vi, flash point, pour point, and aniline point (all standard astm tests). There May also be different elemental additive chemistry.
In the type of application you are talking about, the synthetic gear oil will likely be polyalphaolefin (pao) based. Paos are chemically similar to mineral oils and hence mixing the two should not cause a compatibility problem (especially if both oils are the same api classification). Although, if a synthetic is required, for example cold temperature operation, using a mineral by mistake May cause other problems like stiff shifting in a manual transmission.
Also be aware that in industrial applications, some synthetic gear oils are polyglycol (pag) basestocks, which are chemically incompatible with both pao synthetics and mineral oils. In this case, mixing will result in serious incompatibility issues.
Dick floryanowich
swepco