A. Why Test Lubrication Oils?
Oil Analysis User Guide User Guide
Benefits Of Oil Analysis This guide is designed to assist the user in not only interpreting oil analysis test reports, but implementing appropriate corrective actions as well. well. It is not intended intended to be a definitive reference, but an “at a glance” guide to be used with other reference materials.
To determine when the oils lubricating properties have been depleted. To obtain clues about the mechanical and operating conditions of the equipment. Early warning signals mean problems can be rectified before permanent and costly damage occurs. B. Return On Your Investment Lost production is often the most expensive result of equipment downtime. A good Preventive Preventive Maintenance Program can reduce these costs, and improve production. produc tion. Throug Through h an Oil Analysi Analysis s Program premature premature failures can be reduced, thereby maximizing equipment life and reducing capital costs for new equipment. AGAT Laboratories oil analysis program can also allow the Laboratories development of efficient maintenance schedules, reducing maintenance repair and even lubrication costs. C. Why Establish a Testing Program?
The Warning Signals SIGNAL Viscosity Increase Viscosity Decrease Additive Additi ve Deple Depletion tion High Solids Content Water Contaminatio Contamination n
A consistent testing program is required to determine normal wear from abnormal wear, as each unit will wear differently.. Oil testing programs are most effective when differently sampling is conducted on a regular basis. POSSIBLE CAUSE Soot, lead, water contamination, high temperature operation Fuel dilution, excessive high speed operation High operatin operating g tempera temperature, ture, long drain intervals, improper makeup oil Dirt, dust, soot, engine metals, high temperature operation Coolant leak, low temperature operation, poor mechanical conditions
RESULT Wear rate increase Wear rate increase Reduces lubricating properties, increases wear rate Increases wear rates, reduces life of equipment Reduces lubricating properties of the oil, causes corrosion f ormation
Glycol Contamination
Cooling system leak
Reduces lubricating properties of the oil, causes corrosion f ormation
High W ear Metals
Accelerated normal wear
Reduces the life component
CONTAMINATION IN THE OIL
POSSIBLE CAUSE
Fuel Combustion Products
Soot, sulphur c ompounds, water, lead compounds compounds and partially partially oxidized fuel
Liquid Fuel
Fuel in the oil
Solid Particles
Dirt and airborne dirt, wear metals, rust, corrosion and fuel soot soot
Water Contaminatio Contamination n
Combustion, the cooling system or other mechanical pr oblems
Coolant Contamination
Coolant leaks can react with oil additives
©Copyright 2004 AGAT Laboratories Ltd.
RESULT Increased viscosity, deposit f ormation and can cause corrosion Reduced viscosity, increased wear rates and deposit f ormation Wears vital engine parts as well as increased oil viscosity Rusting and corrosion, forms sludge and acids, reduces lubrication properties of oil Sludge deposits and reduced lubrication properties of the oil
Spectrochemical Analysis Wear Metals/Additives Metal Aluminum ( Al )
Chromium (Cr )
Copper (Cu)
Common Sources Bushings, shims, washers, pistons, bearing cages and surfaces (thrust/turbo), blowers Plating material, seals, bearing cages, piston rings, liners, shafts, may be chromate corrosion inhibitor from coolant system Bearings, bushings (wrist pin), oil coolers, radiators, camshaft thrust washers, gears, valves, clutch plate, sealing compounds
Iron (Fe)
Gears, blocks, cylinder walls/heads, liners, valve guides, piston rings, ball and roller bearings, oil pump, rust
Tin (Sn)
Bearings, bushings, wrist and piston pins, rings, piston overlay seals, solder
Lead (Pb)
Overlay on bearing surfaces, seals, clutch, solder, oil additive in gear lubes, anti-seize or grease compounds, gasoline contamination.
Silicon (Si )
External dirt/dust, grease additive, antifoam additive, gasket sealants
General Purpose Strong, lightweight material (smaller mass) which dissipates heat well and aids i n thermal transfer
Higher than expected Al level. May represent wear or be a component of sil icon dirt. Identify and evaluate source of Al .
Because of its strength and hardness, is used to plate rings and shafts that are usually mated with steel (softer)
Higher than expected Cr level. Mayrepresent component of water inhibitor or engine wear. Identify and evaluate source of Cr .
Utilized to wear first in order to protect other components. Conforms well so is used to seat bearings to the crankshaft. (Remember: Cu + Zn = Brass, Cu + Sn = Bronze) Is used as the base metal of steel in many components due to its strength. Since Iron will rust, it is alloyed with other metals (i.e. Cr, Al, Ni ) making steel Is a conforming material used to plate and protect surfaces to facilitate break-in. Surface coating on components such as pistons Is a conforming material use to plate bearings. Appears in new engines while the bearings are melding and conforming Can be an antifoam additive in the form of silicone. Can be primary indicator of dirt/dust contamination. An alloy used in some piston rings in place of Cr . Also used as a friction modifier (reducer) in some oils.
Molybdenum (Mo)
Surface coating on some piston rings, oil additive (anti-wear)
Nickel (Ni )
Bearing metals, valve stems/guides, ring inserts on pistons, turbo charger blades, stainless steel components
Alloyed with iron in high strength steel, used to make valve stems and guides.
Silver ( Ag )
Bearing cages, silver soldered joints
Is use to plate components because it conforms well, dissipates heat and reduces coefficient of friction.
Coolant additive
Presence in oil may represent coolant contamination.
Coolant additive, grease additive, road salt, ingested dirt
Not a wear metal. Presence in oil may represent coolant contamination.
Potassium (K ) Sodium (Na) Metal Boron (B)
Common Sources Water inhibitor, limited EP additive, coolant additive (borate), grease additive
General Purpose May represent mixing with another product, water inhibitor or glycol.
Barium (Ba)
Detergent additive, grease additive
Calcium (Ca)
“Hard” water, alkaline based additive, road salt
Magnesium (Mg )
Component housing, a constituent in some Al alloys, detergent additive
Oxidation inhibitor (detergent additive)
Manganese (Mn)
Valves, blowers, exhaust and intake systems. Detergent additive (unleaded gas)
Unleaded gasoline additive
Phosphorus (P )
Anti-wear or extreme pressure (EP) additive, coolant additive
Vanadium (V ) Zinc (Zn)
Surface coating, turbine impeller blades, valves Anti-wear additive, oxidation and corrosion inhibitor, brass alloy
Significance of Results (Required Action)
Toxic additive but advantageous because it does not leave excessive ash residue. Used as an oxidation inhibitor and is used to neutralize acids formed in combustion engines (detergent additive)
Used to provide a protective film in highpressure areas. Coolant additive in conjunction with high Na and/or K . Fuel contaminant, can also be alloying element for steel Used to provide a protective anti-wear film.
Higher than expected Cu level. May represent wear, cooling water leaks or scaling compounds. Identify and evaluate source of Cu. Higher than expected Fe level. Mayrepresent wear of rust/scale contamination in case of water leaks. May be critical wear of due to break-in. Identify and evaluate source of Fe. Higher than expected Sn level. May represent bearing wear. Identify and evaluate source of Sn. Higher than expected Pb level. May represent normal flashing wear after overhaul or problem wear. If appears later, misalignment may be indicated. Identify and evaluate source of Pb. Higher than expected Si level. May represent dirt/dust contamination. Identify and evaluate source of Si . Unexpected Mo level. May represent wear or mixing with another product. Identify and evaluate source of Mo. Higher than expected Ni level. May represent initial stages of bearing wear. Identify and evaluate source of Ni . Higher than expected Ag level. May represent bearing wear or initial stages of cooling system degeneration. Identify and evaluate source of Ag . Higher than expected K level. May represent a coolant leak into engine crankcase. Identify and evaluate source of K . Higher than expected Na level. May represent coolant leak into engine crankcase. Identify and evaluate source of Na. Significance of Results / Required Action Unexpected B level. May represent mixing with another product, water inhibitor or glycol. Identify and evaluate source of B. Unexpected Ba level. May represent mixing with another product. Identify and evaluate source of Ba. Unexpected Ca level. Mayrepresent mixing with another product. Identify and evaluate source of Ca. Unexpected Mg level. May represent mixing with another product or gasoline. Possible indication of hard water. Identify and evaluate source of Mg . Unexpected Mn level. May represent mixing with another product or gasoline. Identify and evaluate source of Mn. Unexpected P level. May represent mixing with another product or coolant leak into engine crankcase. Identify and evaluate source of P . Higher than expected V level. May represent component wear. Identify and evaluate source of V . Unexpected Zn level. Mayrepresent mixing with another product. Identify and evaluate source of Zn.
AGAT
Oil Analysis User Guide
Viscosity
The Warning Signals
Viscosity is one of the most important properties of lubricating oil. Viscosity is a measurement of resistance to flow at a specific temperature in relation to time. The two most common temperatures for lubrication oil viscosity are 40 °C and 100 °C. Viscosity is normally evaluated with a kinematic method and reported in centistokes (cSt) In used oil analysis, the used oil's viscosity is compared to that of the new oil to determine whether excessive thinning or thickening has occurred.
SOURCE
RESULT
High Viscosity Contamination soot/solids Incomplete combustion (A-F ratio) Oxidation degradation Leaking head gaskets Extended oil drain High operating temperature Improper oil grade
Increased operating costs Engine overheating Restricted oil flow Oil filter by-pass Harmful deposits or sludge
Low Viscosity Additive shear Fuel dilution Improper oil grade
Increased operating costs Engine overheating Poor lubrication Metal to metal contact
N O I T U L O S
Check air to fuel ratio Check for incorrect oil grade Inspect internal seals Check operating temperature Check for leaking injectors Change oil and filter
Viscosity Grades Low Temperature Viscosities
High-Temperature Viscosities
Low Shear Rate SAE Cranking (cP) Pumping (cP) max Kinematic (cSt) at Viscosity Grade max at temp with no yield stress 100°C °C at temp °C min max
High Shear Rate (cP) at 150°C min
0W
3250 at -30
60,000 at -40
3.8
—
—
5W
3500 at -25
60,000 at -35
3.8
—
—
10W
3500 at -20
60,000 at -30
4.1
—
—
15W
3500 at -15
60,000 at -25
5.6
—
—
20W
4500 at -10
60,000 at -20
5.6
—
—
25W
6000 at -5
60,000 at -15
9.3
—
—
20
—
—
5.6
<9.3
2.6
30
—
—
9.3
<12.5
2.9
40
—
—
12.5
<16.3
2.9 (0W-40, 5W-40, 10W-40 grades)
40
—
—
12.5
<16.3
3.7 (15W-40, 20W-40, 25W-40, 40 grades)
50
—
—
16.3
<21.9
3.7
60
—
—
21.9
<26.1
3.7
©Copyright 2004 AGAT Laboratories Ltd.
Viscosity Equivalents Kinematic Viscosities CSt 40°C
800
Grade Systems
CSt 100°C
ISO
AGMA
40
680
8
30
480
7
320
6
220
5
SAE ENGINE OIL
SAE GEAR OIL
600 500 400 350 250
20
140
50 90
200 16 150 100 80
10 9
60
8
50
7
40
6
30
5
20
4
15 10
150 100
4 3
68
2
46
1
40 85W 30 80W 20
32 22
75W 10W 5W
15
10
) t S c ( y t i s o c s i V
SAE 30
VI = 95
SAE 10W30
VI = 120
SAE 10
VI = 95
Temperature ( °C)
AGAT
Oil Analysis User Guide
Acid Number (An) Acid Number (AN) is the quantity of acid or acid-like derivatives in the lubricant. An increase in AN from that of the new lubricant should be monitored. The AN of a new oil is not necessarily nil since oil additives can be acidic in nature. Increases in AN usually indicate lubrication oxidation or contamination with an acidic product. AN is an indicator of oil serviceability.
SOURCE High sulphur fuel Overheating Excessive blow-by Extended oil drain intervals Improper oil type
N O I T U L O S
Base Number (Bn) Base Number (BN) represents the amount of alkaline additives in the lubricant, which neutralizes the acidic products of combustion.
RESULT Decreased base number (BN) Corrosion of metallic components Promotes oxidation Oil degradation Oil thickening Additive depletion
Drain oil Reduce oil drain intervals Confirm oil type being used Check for overheating Check fuel quality
SOURCE
RESULT
Low BN High sulphur fuel Overheating Extended oil drain Improper oil type
N O I T U L O S
Increased acid number ( AN ) Oil degradation Increased wear rate Acid build-up in oil
Use low sulphur diesel fuel Re-evaluate oil drain intervals Verify base number of new oil being used Verify oil type being used Change oil Test fuel quality Check for loose fuel crossover lines
14 12 10 H P
8 6 4 2 0 0.0
0.5
1.0
1.5
2.0
2.5
Titrant Volume (eq)
©Copyright 2004 AGAT Laboratories Ltd.
3.0
3.5
SOURCE
Metal to metal contact Poor lubrication Cylinder ring wear Depleted additives Decreased oil pressure Reduced fuel mileage (mpg) Reduced engine performance Shortened engine life
Incorrect air to fuel ratio Extended idling Stop and go driving Defective injectors Leaking fuel pumps or lines Incomplete combustion Incorrect timing
N O I T U L O S
Fuel Dilution
RESULT
Fuel dilution of crankcase oil by unburned fuel reduces lubricant effectiveness. The thinning of lubricant can lead to decreased lube film strength adding to the risk of abnormal wear. Depending on certain variables, when fuel dilution exceeds 2.5% to 5%, corrective action should be taken. Fuel dilution is measured by both gas chromatography and fuel dilution meters.
Check fuel lines, worn rings, leaking injectors, seals, pumps Examine driving or operating conditions Check timing Avoid prolonged idling Change oil and filters Check quality of fuel Repair or replace worn parts
Flashpoint
250° C
230°C
t n i 210°C o p h s 190°C a l F
SAE 30 SAE 20W/20
170°C
150°C
2%
3%
4%
5%
Diesel Fuel Content
Flashpoint is used to determine fuel contamination or the flammability hazard of a sample. Flashpoint (°C) can be taken as absolute or correlated against the sample viscosity to determine the percentage (%) of fuel in the sample. Water and glycol can bias this test. Flashpoint is done on fuels, engine oils and large bath application oils.
Figure 3. Diesel fuel content and Flashpoint in motors oils (By Volume)
AGAT
Oil Analysis User Guide
Solids
SOURCE
Solids represent a measurement of all solid and solid-like material in a lubricant. The makeup of solids depends on the system. In diesel engines, fuel soot is usually the major component measured. In non-diesel components, wear debris and oil oxidation products are measured.
Fuel Soot Fuel Soot is formed of carbon and is always found in diesel engine oil. Laboratory testing is used to determine the quantity of fuel soot in used oil samples. Recent EPA emission regulations have placed greater importance on fuel soot levels. The fuel soot level is a good indicator of engine combustion efficiency and should be monitored on a regular basis.
Extended oil drain intervals Environmental debris Wear debris Oxidation by-products Leaking or dirty filters Fuel soot
N O I T U L O S
©Copyright 2004 AGAT Laboratories Ltd.
Shorter engine life Filter plugging Poor lubrication Engine deposits Formation of sludge Accelerated wear Decreased oil flow
Drain oil Flush system Change operating environment Reduce oil drain intervals Change filters
SOURCE Improper air/fuel ratio Improper injector adjustment Defective spray pattern Poor fuel quality Incomplete combustion Low compression Worn engine parts/rings
RESULT Poor engine performance Poor fuel economy Harmful deposits or sludge Increased wear Carbon deposits Clogged filters, reduced filter life
Ensure injectors are working properly Check air induction / filters Change oil Assess oil drain intervals Check compression Avoid excessive idling Inspect driving and operating conditions Check fuel quality
N O I T U L O S
Oxidation Lubricating oil in engines and other c om po ne nt s c om bi ne s w it h available oxygen under certain conditions to form a wide variety of h ar mf ul by -p ro du ct s. H ea t, pressure and catalyst materials accelerate the oxidation process. By-products of oxidation form lacquer deposits, corrode metal parts and thicken oil beyond its ability to lubricate. Most lubricants contain additives which inhibit or retard the oxidation process. Differential infrared analysis is the method used to measure the level of oxidation in used oil.
RESULT
SOURCE Overheating Extended oil drain intervals Improper oil type / inhibitor additives Combustion by-products / by-blow
N O I T U L O S
RESULT Shortened equipment life Oil filter plugging Increased viscosity Corrosion of metal parts Increased operating expenses Increases wear rate Decreased engine performance
Use oil with oxidation inhibitor additives Shorten oil drain intervals Check operating temperatures Check quality of fuel
Nitration
SOURCE
Nitration products are formed during the fuel combustion process when combustion byproducts enter the engine oil during normal operation or as a result of abnormal blow-by past the compression rings. These products are highly acidic, create deposits and accelerate oil oxidation. Infrared analysis represents the only method of accurately measuring nitration products in used oil.
Improper scavenge Low operating temperatures Defective seals Improper air/fuel ratio Abnormal blow-by
N O I T U L O S
Particle Count
Accelerated oxidation Nitrous oxides introduced into the system Acidic by-products Increased cylinder wear Oil thickening Combustion deposits Increased acid number ( AN )
Increase operating temperature Check crankcase venting hoses And valves Ensure proper air/fuel mixture Perform compression check
SOURCE
Particle Count testing basically measures the relative cleanliness of a given fluid. It is primarily used for hydraulic and turbine systems to evaluate the effectiveness of the filters. It has been proven that reducing the particulate debris in the fluid can greatly increase the life of these systems.
RESULT
Water contamination Oil oxidation Worn seals Ineffective filtration Dirty make up oil
The instrument that is normally used is a HIAC/ROYKO Particle Counter that measures the total population of particles in different size ranges. High levels of water can produce erroneously high readings. After the analysis is completed, an ISO Cleanliness Rating is determined from the results. The ISO Cleanliness Rating consists of two numbers and is a convenient method to communicate the sometimes unwieldy particle count results. The first number represents 5-micron (silt) particles. The second number represents 15micron (abrasives) particles.
Typical fluid cleanliness levels for hydraulic
RESULT
N O I T U L O S
Increased wear Equipment/System failure Plugging and/or leakage Pressure pulsing Sluggish valves or actuators
Change filter Change oil Use higher quality filters Ensure integrity of seals
Component Types
Normal
Abnormal
Excessive
Servo Control Valves
14 / 11
16 / 13
18 / 15
Vane and Piston Pumps
16 / 13
18 / 15
20 / 17
Directional and Pressure Control Valves
16 / 13
18 / 15
20 / 17
Gear Pumps
17 / 14
19 / 16
21 / 18
Flow Control Valves and Cylinders
18 / 15
20 / 17
22 / 19
Data Acquisition: In order to assign an ISO Cleanliness Rating to represent the contamination level of a fluid, the number of particles greater that 5 micron and 15 micron unit volume must be available. Furthermore, the particle population must be obtained from a particle counting system which has been calibrated per ISO/DIS 4406 or an ISO approved equivalent method in order to assign a valid cleanliness rating. The actual counting system is immaterial as long as the acceptable calibration certification is available.
AGAT
Oil Analysis User Guide
ISO Cleanliness Rating Reference Chart International Standard ISO 4406 Particle Concentration (number of particles per)
# per ml More than 5 000 000 2 000 000 1 300 000 640 000 320 000 160 000 80 000 40 000 20 000 10 000 5 000 2 500 1 300 640 320 160 80 40 20 10 5 2.5 1.3 0.64 0.32 0.16 0.08 0.04 0.02 0.01 0.005 0.0025
Up to and including 10 000 000 5 000 000 2 000 000 1 300 000 640 000 320 000 160 000 80 000 40 000 20 000 10 000 5 000 2 500 1 300 640 320 160 80 40 20 10 5 2.5 1.3 0.64 0.32 0.16 0.08 0.04 0.02 0.01 0.005
©Copyright 2004 AGAT Laboratories Ltd.
# per 100 ML 500M – 1000M 200M – 500M 130M – 200M 64M – 130M 32M – 64M 16M – 32M 8M – 16M 4M – 8M 2M – 4M 1M – 2M 500K – 1M 250K – 500K 130K – 250K 64K – 130K 32K – 64K 16K – 32K 8K – 16K 4000 – 8000 2000 – 4000 1000 – 2000 500 – 1000 250 – 500 130 – 250 64 – 130 32 – 64 16 – 32 8 – 16 4–8 2–4 1–2 0.5 – 1 0.25 – 0.5
ISO Range Number 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0.9 0.8
Glycol Analysis PARAMETER
RESULT
pH
7-11
Reserve Alkalinity
7 or greater
Depletion of corrosion inhibitors
T.S.S.
< 1200 ppm
Poor water quality, scale or corrosion buildup, poor filters, reservoir open to atmosphere, component wear
Freeze Point
< -30 °C
Glycol to water ratio to low
Glycol Strength
50 – 60 %
Glycol to water ratio to low
Soluble Iron
< 2 ppm
Soluble Copper
< 1 ppm
Soluble Lead
< 3 ppm
Total Aluminum Total Phosphorus
< 2 ppm
POSSIBLE SOURCE Depletion of additives
Improper coolant, pump wear, defective pressure caps, air leaks, cavitations, hoses Improper coolant, pump wear, defective pressure caps, air leaks, hoses Improper coolant, pump wear, defective pressure caps, air leaks, hoses Improper coolant, pump wear, defective pressure caps, air leaks, hoses
300 – 500 ppm
Coolant additive
Total Silicon
50 – 250 ppm
Coolant additive, dust entry, silicon sealant
Sulfate
< 100 ppm
Nitrite
800 – 2400 ppm
Chlorides
< 40 ppm
HCl cleaners, poor water quality
Sodium
< 200 ppm
Coolant additive
Salt as NaCl
< 200 ppm
Free CO2
< 1000 – 2000 ppm
Conductance
< 6000 ppm
Total Hardness Specific Gravity
< 170 ppm 1.050 – 1.14
Poor water quality, SO 4, cleaner, gas leak into the system Defective pressure caps, gas leak into the system, water pump drowning air, insufficient chemicals
Poor water quality, defective pressure caps, old coolant, HCl cleaners Water pump drowning air, defective pressure caps, old coolant, HCl cleaners. Transportation of sample Poor water quality, gas leak into the system Poor water quality Glycol to water ratio
AGAT
Oil Analysis User Guide
Interpreting the results, Test reports and taking corrective action Once all of the tests are complete, highly trained Quality Assurance personnel evaluate the results. The evaluation will result in (1) a statement that the unit is normal, or (2) general maintenance recommendations will be made. The report recommendations are only one tool that can assist you in making your maintenance decisions.
Recommendation Categories Normal No explanation is needed for this category. Keep in mind that it is important to know that a unit is normal. This can save you unnecessary teardown. Abnormal (Reportable) This category is followed by specific maintenance recommendations, or a notation that component wear is abnormal/reportable. There might, for example, be a recommendation to change oil and filters, and a comment noting that abnormal bearing wear is present. We are not telling you that it is time to tear down the unit. We are suggesting that you perform the maintenance suggested, and advising you that bearing wear is present. A second sample (resample) in a shorter t i m e s p a n m i g h t b e requested/recommended. We do not recommend that you go into a unit on an abnormal recommendation unless you have thoroughly discussed the report with the appropriate Laboratory personnel (if required) or you have indications that the unit has a more serious problem than is apparent in the report. Again, your judgment must be based on all of the tools at your disposal, including our report, your knowledge of the unit, manufacturers guidelines/recommendations, your experience, etc...
©Copyright 2004 AGAT Laboratories Ltd.
Critical This is the category we use to indicate potential failure and that serious condition exists. We will indicate the suspected nature of the problem and make a general recommendation for maintenance action. Critical units generally require immediate attention. Re-samples: Additional samples (re-sampling) are recommended to establish a trend whenever we have a potential “critical” unit with no previous history. If the wear increases, you will be advised of the suspected nature of the problem. Re-sampling may be recommended as a way to verify proper sampling techniques or contamination through the sampling procedure. In some cases, the data will identify an obvious problem. For example, a high level of water contamination along with high levels of sodium, potassium and boron is a good i ndication of antifreeze contamination. A high particle count and high levels of silicon usually indicate dirt or dust contamination, and the need to check air filters or breathers, reservoir access covers or oil storage and handling procedures. Sometimes however, the analytical data from an individual sample does not provide enough information to make more subtle judgments about oil or equipment condition. In these situations it is necessary to monitor the trends in the analytical data over a series of samples to establish a wear trend pattern. By monitoring wear metals such as iron, lead, copper, and tin it is possible to detect the early stages of possible bearing failure. In most cases it can detect problems far enough in advance that it will allow for scheduling of bearing inspection at a convenient time, reducing or eliminating expensive equipment downtime and repairs.
One measure to the degradation of an engine is an increase in viscosity. Normally, a viscosity increase from one grade to the next is a warning that the oil has reached the end of its useful life. Most engine oils are formulated with a variety of additives which enhance lubricity, inhibit oxidation and corrosion, and reduce the tendency for sludge and deposit formations. The levels of these additives can be determined by monitoring the Base Number (BN). The reduction of a (BN) below 4.0 is a warning that the additives have been depleted and an oil change should be scheduled. Some additive levels can be measured with spectrographic metals analysis. This test will detect the levels of zinc, phosphorus, calcium, magnesium, … which are common elements in most additive packages. The most common engine oil contaminants are silicon (dirt), fuel dilution, and antifreeze coolant. Silicon (dirt) contamination is the most common form of contamination and causes serious engine wear due to its abrasive actions against all moving parts within the engine. Silicon levels above 25ppm should be considered cause for inspection of the air intake system to locate the source of entry for the dirt and other airborne debris. Fuel dilution is serious since it can significantly reduce oil viscosity and lubricity thus causing engine wear. Fuel dilution can initially be detected by a lowering of the flash point of the oil, accompanied by a noticeable viscosity reduction, and a heavy fuel odor.
Interpreting the results, Test reports and taking corrective action
Wear metal analysis can indicate which engine components are wearing and if the wear is becoming significant. This information can make the difference between minor component inspections and repairs and major overhauls. Wear metal levels, provided by spectrographic analysis of the oil sample, indicate the element level in parts per million (ppm) of each of the common metals found in the engine (iron, aluminum, chromium, lead, copper, tin, nickel, silver). Wear metal analysis requires more than simply plotting data on a graph. Wear metals can be generated from as many as a dozen different engine parts and locations making it difficult to identify the specific part that is wearing excessively. It is the knowledge acquired through years of experience and analytical training.
Coolant is another very common oil contaminant and probably the most serious. Water from the coolant reduces the lubricity, which causes severe bearing problems, while the glycol degrades at high temperatures and forms a sludge. Monitoring water contamination levels is not reliable, since normal engine temperatures are high enough to evaporate the water over time and keep detectable levels as low as 0.05%. Coolant levels can be detected by chemical analysis and by monitoring the levels of boron, sodium and potassium in the oil.
AGAT
Oil Analysis User Guide
Sampling Guidelines FLUID TYPE OR SYSTEM
REGULAR USE
INTERMITTENT
500 hours or monthly 500 hours or monthly 500 hours or monthly 250 hours or monthly Quarterly 500 hours or monthly 250 hours or monthly Quarterly 500 hours or monthly 500 hours or monthly 500 hours or monthly As required Every new shipment Quarterly
Quarterly Quarterly Quarterly Quarterly Annually Quarterly Quarterly Annually Quarterly Quarterly Quarterly As required Every new shipment Quarterly
150 Hours 50 Hours 100 Hours 250 Hours Every new shipment Quarterly Annually
100 hour inspection and annually 100 hour inspection and annually 100 hour inspection and annually 100 hour inspection and annually Every new shipment Quarterly Annually
250 Hours 500 Hours 500 Hours 500 Hours 150 Hours As needed for troubleshooting Every new shipment Quarterly Annually
Quarterly Quarterly Quarterly Quarterly Quarterly As needed for troubleshooting Every new shipment Quarterly Annually
10,000 miles or 250 hours 20,000 miles or 500 hours 20,000 miles or 500 hours 20,000 miles or 500 hours 3,000 miles or 150 hours As needed Every new shipment Quarterly Annually
Quarterly Quarterly Quarterly Quarterly Quarterly As needed Every new shipment Quarterly Annually
Stationary Industrial Equipment Gear Drives Compressors Hydraulic Systems Turbines Transformers Hot Oil Systems / Oil Baths HVAC Compressors HVAC Refrigerants Diesel Engines Natural Gas Engines Coolants Vehicle Fuel Tanks New Diesel Fuel Loads Diesel Fuel Storage Tanks
Aviation Equipment Turbine Engines Piston Engines Gear Drives Hydraulic Systems New Aircraft Fuel Loads Storage Tanks (Bottom) Storage Tanks (Center)
Marine Equipment Main Engine Non Engine Hydraulic Systems Coolants Support Engine Systems Vehicle Fuel Tanks New Marine Fuel Loads Storage Tanks (Bottom) Storage Tanks (Center
Highway Equipment Diesel Engines Gearboxes Hydraulic Systems Coolants Gasoline or LPG Engines Vehicle Fuel Tanks New Diesel Fuel Loads Storage Tanks (Bottom) Storage Tanks (Center)
©Copyright 2004 AGAT Laboratories Ltd.
Sampling Guidelines UNIT TYPE OR SYSTEM
COMPONENT TYPE
FREQUENCY
Diesel Engines Hydraulic Gearbox Wheel Motors Coolant Diesel Engine Transmission Hydraulic Differential Final Drive Wheel Hub Coolant Engine Transmission Hydraulic Differential Final Drive Steering Coolant Engine Transmission Hydraulic Differential Coolant Engine Transmission Hydraulic Engine Engine Sump Reciprocating/Centrifugal Agitators, Conveyers, etc. Hydraulic Gearbox Engine Gears, Bearings, Sump Transformer
250 Hours 250 Hours 250 Hours 250 Hours Quarterly 250 Hours 500 Hours 500 Hours 500 Hours 500 Hours 500 Hours Quarterly 250 Hours 500 Hours 500 Hours 500 Hours 500 Hours 500 Hours Quarterly 250 Hours 500 Hours 500 Hours 1000 Hours Quarterly Quarterly 6 Months 6 Months 6 Months Monthly Monthly Monthly 2 Months 500 Hours Monthly 500 Hours 2 Months Annually
Mining Equipment Electric Haul Truck Electric Haul Truck Electric Haul Truck Electric Haul Truck Electric Haul Truck Mechanical Haul Truck Mechanical Haul Truck Mechanical Haul Truck Mechanical Haul Truck Mechanical Haul Truck Mechanical Haul Truck Mechanical Haul Truck Dozers Cranes Hoists Graders Loaders Scrapers Shovels Water Trucks Water Trucks Water Trucks Water Trucks Water Trucks Flatbeds Forklifts Forklifts Pickups Compressor Compressor Air Compressor Misc. Handling Equipment Electrical Fans & Blowers Generators Pumps Transformers
AGAT
Oil Analysis User Guide
Oil Sampling Techniques Drain Port Sampling
SS Tube Ball Valve Drain Plug
Drain-port sampling
Drop-Tube Vacuum Sampling (Vampire Pump) Flush assembly and tube first
Drain-port tap sampling
Sample from a Live Zone
Probe-on Style Valve
Vaccum Sampler
Twisty Rod
Flush Valve First Place clean plastic film over bottle opening before threading into cavity Leave¼ on bottle unfilled (Ullage)
Measure Standoff
Sampling Inlet Sludge Line
©Copyright 2004 AGAT Laboratories Ltd.
Turbulent Fluid Line (Return Line)
Oil Sampling Techniques Sampling Engines
Diesel Engine
Cooler
Sample Here Pump Filter Sump
Hydraulic Sample Point
Gear Box Sample Point
Fill Port
Sample Here Drain Port
Portable Circulating System
AGAT
Oil Analysis User Guide
Oil Sampling Techniques Sampling Engines
Air in
In let Air filter
Sample on circulating system before filter
Air/Oil Separator and Receiver Air Out
r e l o o C l i O
Screw Compressor
Reservoir
Temperature Regulaing Valve
Sample air compressor more frequently than gas compressors Sample oil flooded compressors more frequently than reciprocating and centrifugal compresors
Oil filter
Sample here
Air
Oil
Air, Oil
Turbine Sample Point
Main Pump
e Cen tr i fug Pump
Oil Coolers
Primary Sampling Point for trending Secondary Sampling Point for diagnostics
O i l rv o ir R e se
Water Drain
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O i l r i t i o ne C o n d
Notes
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