Our client experienced a significant water and debris contamination event in the Fixed Bearing circuit of the SAG Mill. The mill was immediately shut downto avoid bearing damage and the contaminated oil was removed and new then oil introduced. Even so, there was concern that the circuits still had potentially harmful debris and moisture present. For More Update, Visit Us http://www.biokem.com.au/
Oil Analysis in Australia
Sunday 17 April 2016
Sunday 20 March 2016
Moisture could be your No. 1 Lube Oil Problem
Compressors handling ‘sour’ natural gas with higher levels of Hydrogen sulphide can strike real problems if the oil interacts with the product gas and any moisture is present. The result is an attack on the compressor alloys called sulphide stress cracking, a form of hydrogen embrittlement. In extreme cases this can cause a compressor casing to split.
Additives are designed to be a sacrificial product. They are consumed as the additive pack anti-oxidant neutralises unwanted chemical contaminants. However, if additives such as demulsifiers (which help shed water) are exposed to large amounts of water contamination, the demulsifiers can be stripped from the oil very quickly leaving the oil at risk.
Other additives like Extreme Pressure (EP) and Anti-wear (AW) can be hydrolyzed (broken down into acids) by water and deny your Equipment the protection those additives are designed for. If left unchecked the by-product is sludge and varnish.
A trial of machines by the BHRA compared equipment life to moisture contamination. They found the correlation between dry oil and oil with high moisture content. Oil with a moisture level of 5,000 ppm was dehydrated and trialled to measure equipment life. The results show that equipment with oil drier than 100ppm has three times the life of a machine with oil of 450ppm moisture.
To Know More Information, Visit Us http://www.biokem.com.au/
Wednesday 16 March 2016
The Hidden Dangers of Topping Up Your Lube Oil
Synthetic lubricants were born out of a need for better lubricating
properties, and the unavailability of crude oil in Germany. Aviation was
the first application for synthetic lubricants, as they are superior to
mineral oils at cold start up and cold climates. Synthetic oils have a
higher Viscosity Index, offering better viscosity stability at varying
temperatures. Group IV synthetic oils are man-made from PAO’s
(polyalphaolefins) and Group V oils are made up of polyesters, phosphate
esters, di-esters, alkylated benzenes and other synthetic molecules.
Another way of comparing the various refinement of oil is to compare the oil to a fluid with balls of varying sizes in suspension. The lower the Group level of oil, the greater variety of ball size and shapes (which represent the types of molecules). Group 1 oils will have millions of differing atomic compounds (molecules) making up the oil. As the oil is refined, the oil is more uniform and the ‘balls’ are the same size. Synthetic oils have only one size ball.
For More Update, Visit Us http://www.biokem.com.au/
Another way of comparing the various refinement of oil is to compare the oil to a fluid with balls of varying sizes in suspension. The lower the Group level of oil, the greater variety of ball size and shapes (which represent the types of molecules). Group 1 oils will have millions of differing atomic compounds (molecules) making up the oil. As the oil is refined, the oil is more uniform and the ‘balls’ are the same size. Synthetic oils have only one size ball.
For More Update, Visit Us http://www.biokem.com.au/
Sunday 26 April 2015
How do you know if you have varnish in your lube system?
Lubricant breakdown
accounts for more than 50% of your machine failures.
Lubricant Breakdown
Premature
failure from lubricant breakdown is the
most common cause of machinery failure, because it is largely misunderstood
and ignored. Here are some clear signs for
you to look for a problem without waiting on lab reports:
WARNING SIGNS:
·
Change
in oil colour
·
Strong
or burnt odour
·
Change
in oil consistency
·
Sludge
and deposits on lube tank walls and floor
·
Visible
contaminants in the sample bottle
Any
of these generally indicate that your oil has undergone a chemical change and
will no longer perform to the standard it was designed to. Breakdown of the oil can occur from
particulate contaminant, fuel or gas entrainment, oxidation and thermal stress,
but the most common cause is from water contamination.
What is varnish?
Varnish
(also known as sludge, tar and lacquer) is a soluble and insoluble
contaminant made up of by-products of oil degradation.
It
can appear as resinous, sticky, tacky or a gel-like substance that settles or
plates out on the surfaces of the lube system.
This can cause ‘stiction’ on servos and affect clearances and tolerances
in bearings and hydraulic control systems and valves.
As
oil degrades, it consumes its additives packages and antioxidant properties and
waste by-products are formed, creating sludge and varnish. You will have seen
it in hydraulic components, inside engine rocker covers and on journal bearing
surfaces or sumps.
There are many causes of
varnish and sludge, but clean oil is not one of them!
Is your system susceptible?
There
are a number of explanations for why lube oils suffer from high rates of
varnish. If your system ticks any of these boxes then you should
ensure your lab is testing for varnish potential:
Effect of varnish on equipment |
ü Visible deposits or staining
of lube circuit components
ü Switched from Group I to Group II or
blend of oils
ü Gas turbine or hydraulic application
ü High flow rate from a small
lube reservoir
ü High operating temps
ü Your chosen oil brand is
predisposed to varnish formation
The effect of varnish on equipment
If
left unchecked, varnish can propagate at an exponential rate, creating hot
spots, prematurely plugging filters or oil gallery orifices, and coating heat
exchangers and rendering them thermally inefficient. Hydraulic control systems
and valves can gum up or seize, causing unit trips and starting faults. Also, hard particles canadhere to varnished
components and cause premature wear.
The
cost of a gas turbine or hydraulic system not starting immediately can be
enormous as these are the assets that are designed to work at the press of a
button to meet supply requirements.
All
lubricating systems are subject to varnish potential if not maintained. The biggest cost to industry from varnish is
unscheduled downtime and lost production. There is a yawning cost-gapfrom an unscheduled
shutdown or unit trip, in comparison to condition monitoring and cost of varnish
mitigation.
Effect of varnish on equipment |
Varnish Detection
If
you suspect that varnish could be a problem then additional laboratory analysis
can identify varnish potential within your system. Sometimes, it can be as simple as pulling
filters and strainers and visibly observing the flakes and sludge indicating the
oil has broken down. Check your oil
sample bottle & sheet to see if your lab can test for these:
Membrane Patch Colorimetry (MPC)
This
is an excellent test to determine varnish potential. It is very sensitive and literally assesses
the colour spectrum of the oil. MPC
analyses (L) white to black, (a) red to green, and (b) yellow to blue scales
providing information on not only the seriousness of varnish found but the
likely cause.
High L = presence of soot, evidence of
micro-dieseling, spark discharge, thermal stress.
High a = diminished EP additives, likely to
produce sludge
High b = sticky, gummy deposits.
MPC Patches showing varnish potential high to low: results are 52, 44, 32, & 21 respectively. |
Remaining Useful Life Evaluation Routine (RULER)
The
RULER test quantitatively measures the remaining antioxidants concentration in
the oil, and as it says can determine ‘the remaining useful life of the oil’.
This is a comparison test, so ideally requires the original base oil to be
supplied.
Other Tests
MPC
and RULER should be enough, however other methods to determine varnish
potential can include ultra-centrifuge, particle contaminant levels, TAN (Acid
number), moisture testing and FTIR.
What should you do if you have
varnish?
Don’t
ignore it…
Varnish,
if present in a lube system must be managed and controlled.Predictive
maintenance of your unit is far cheaper than reacting to an event, if the cues
were there and were ignored the flow on effect could be significant.
Can
you live with a major breakdown?
If
you do no nothing, varnish will
cause the machine to suffer a breakdown or component failure, at potentially
huge cost. You cannot predict when the
failure will occur, but it will happen… guaranteed. Get the problem resolved, send us your lab
reports, RCA and specs and we can assist.
What solutions can be deployed?
Specialist
filtration
can remove varnish from a system. No two
systems are the same, so a tailored solution is needed. Your existing oil may or may not be able to
be renewed depending on the type and seriousness of the contaminants. Specialist filtration of the lube tank oil can
remove varnish plated out within the entire lube circuit. This process will take time and may need to
be a permanently installed solution.
In
circumstances where the oil is heavily contaminated and the additives packs left
with Elvis, then the oil will need to be replaced. When this occurs a chemical additive,such as Boost VR or Exxon System Cleaner, can be used to sacrificially
drag the varnish contaminant out with the outgoing oil.
There
are several filtration methods of removing varnish in service. A system such as VRS or ESP (Electrophysical Separation
Process) are the most efficient at removing the soluble contaminants in
suspension, and insoluble contaminates (the varnish and sludge that can be
seen). Prior to any varnish mitigation solution being deployed, the oil will
also require purification to remove any particulate, water or gas contamination.
Summary
Varnish
and sludge is like a cancer of the oil, if not treated, it spreads and further
propagates, to the point of machinery seizure and failure.
Varnish
detection and mitigation is far cheaper than an unplanned shutdown… as with
most things prevention is cheaper than the cure.
Don’t park the ambulance at
the bottom of the cliff!
Monday 20 April 2015
The obvious answer is ‘No’, as there are other influencing factors that impact on equipment life such as start-up wear and vibration… but equipment life when oil is clean may surprise you.
Clean Oil Really Does Matter
When you order ‘new’ oil in to stock it typically has an ISO 4406 code of 21/18/16 NAS 10, which is very dirty for close tolerance rotating machinery. Most OEM’s specify a cleanliness code of 16/14/12 NAS 5, which is substantially cleaner than new oil, but if you can reduce that cleanliness code to 15/12/10 NAS 4, you will extend the machinery life cycle by two and a half times. So, if your rotating asset costs $10M with a service life of 20 years, you could expect a service life cycle of 50 years, so $10M for a 50 year service life is a prudent investment compared to $25M for the same service life.
The British Hydraulics Research Association (BHRA) conducted a three year field study of a range of more than 100 rotational and hydraulic machines to ascertain equipment life and the results were compelling.
What the survey found was that breakdowns diminished and the life of equipment improved greatly the cleaner the oil was kept. Nearly 20 times longer… It proved that if you want to spend less in maintenance and downtime, simply keep your oil clean.
Case Study - Aluminium Smelter
A Queensland aluminium smelter which adopted a proactive condition monitoring program, has changed its hydraulic oil overhaul schedule from annually out to 7 years, by fitting desiccant breathers, servicing the oil with vacuum dehydration and fine filtration. Traditionally, their gearboxes gave 10 years of service life, and now the gearboxes have a service life expectancy of 25 years. Downtime and wear rates have been greatly reduced so they are confident about moving to a synthetic lubricant. Synthetic lubricants do not tolerate moisture or particulate contamination as well as mineral oil but do improve your equipment life when kept clean.
There are many successful examples of this proactive condition monitoring, where operational and maintenance budgets have been greatly reduced and equipment capital budgets are halved.
Take Action with Your Lubricants
You want to see thumbs up on your Lab reports...
There are many successful examples of this proactive condition monitoring, where operational and maintenance budgets have been greatly reduced and equipment capital budgets are halved.
Fact - Keep your in-service oil clean and dry and unscheduled downtime, failures, hot spots, wear, and breakdowns will reduce.
The Cost Benefit Analysis
As an added benefit, the expenditure for implementing proactive condition monitoring and lubrication filtration servicing is insignificant, compared to the savings in capital and operational up-time. One unscheduled stoppage in a plant could pay for years of lubrication maintenance and service.
What are you wanting to see on your lab tests?
Summing Up
It may be naïve to suggest close tolerance machinery can last forever, but you can increase its service life cycle by multiples saving you money and maintenance headaches, all by simply keeping your lube oil clean.
So yes, your close tolerance machinery can nearly last forever, if your lube oil is well serviced.
If you would like further information on this article or others, please let me know or visit our website.
James McAllister
james@biokem.com.au
Ph 0466 625 225
www.biokem.com.au
Clean Oil Really Does Matter
When you order ‘new’ oil in to stock it typically has an ISO 4406 code of 21/18/16 NAS 10, which is very dirty for close tolerance rotating machinery. Most OEM’s specify a cleanliness code of 16/14/12 NAS 5, which is substantially cleaner than new oil, but if you can reduce that cleanliness code to 15/12/10 NAS 4, you will extend the machinery life cycle by two and a half times. So, if your rotating asset costs $10M with a service life of 20 years, you could expect a service life cycle of 50 years, so $10M for a 50 year service life is a prudent investment compared to $25M for the same service life.
ISO 20/18/16 NAS 10 as delivered 'new'! |
ISO 15/12/10 NAS 4 - Post filtration, clean |
What the survey found was that breakdowns diminished and the life of equipment improved greatly the cleaner the oil was kept. Nearly 20 times longer… It proved that if you want to spend less in maintenance and downtime, simply keep your oil clean.
Case Study - Aluminium Smelter
A Queensland aluminium smelter which adopted a proactive condition monitoring program, has changed its hydraulic oil overhaul schedule from annually out to 7 years, by fitting desiccant breathers, servicing the oil with vacuum dehydration and fine filtration. Traditionally, their gearboxes gave 10 years of service life, and now the gearboxes have a service life expectancy of 25 years. Downtime and wear rates have been greatly reduced so they are confident about moving to a synthetic lubricant. Synthetic lubricants do not tolerate moisture or particulate contamination as well as mineral oil but do improve your equipment life when kept clean.
There are many successful examples of this proactive condition monitoring, where operational and maintenance budgets have been greatly reduced and equipment capital budgets are halved.
Take Action with Your Lubricants
You want to see thumbs up on your Lab reports...
There are many successful examples of this proactive condition monitoring, where operational and maintenance budgets have been greatly reduced and equipment capital budgets are halved.
Fact - Keep your in-service oil clean and dry and unscheduled downtime, failures, hot spots, wear, and breakdowns will reduce.
The Cost Benefit Analysis
As an added benefit, the expenditure for implementing proactive condition monitoring and lubrication filtration servicing is insignificant, compared to the savings in capital and operational up-time. One unscheduled stoppage in a plant could pay for years of lubrication maintenance and service.
What are you wanting to see on your lab tests?
Summing Up
It may be naïve to suggest close tolerance machinery can last forever, but you can increase its service life cycle by multiples saving you money and maintenance headaches, all by simply keeping your lube oil clean.
So yes, your close tolerance machinery can nearly last forever, if your lube oil is well serviced.
If you would like further information on this article or others, please let me know or visit our website.
James McAllister
james@biokem.com.au
Ph 0466 625 225
www.biokem.com.au
Copyright © 2015 BioKem Oil Services, All rights reserved.
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You are receiving this email as I have your contact email on my personal database from a conference, seminar or we have worked together.
Our mailing address is:
BioKem Oil Services
PO Box 8202
Woolloongabba
Brisbane,
Qld 4102
Australia
Why You Must Eradicate Contaminants from Your Lube Oil
Regardless of contaminant type, any lube system will be compromised if contaminated. The effect can then compound as some contaminants have a catalyst effect, causing further problems. The types of contaminants are quite varied including hard particles, soft particles, moisture and free water, gas and varnish.
Over the next few articles we will cover the range of issues that you should consider when managing your lubrication oil for close tolerance machines, hydraulics and gearboxes.
What you cannot see is doing the damage
Silica & Bright Metal at 100x
Let’s start with the types of contaminants:
Hard particles will score and wear away lubricated surfaces, producing other contaminants in the lube oil, creating a snowball effect of increased wear rates. Wear particles and contaminants that oxidise, will deplete the antioxidants in additive packages, leading to varnish potential.
Soft contaminants have the potential to damage lubricated surfaces and increase wear rates, as well as depleting antioxidants, plugging filtration systems and galleries.
Varnish is a by-product of contaminants or depleted antioxidants, and a real concern in any lube system as the damage caused by varnish includes sticky and gummed valves and actuators, decreased tolerances which restricts lubrication to the wearing components causing higher operating temperatures. Varnish can also plate out on bearing surfaces, causing hot spots and journal deformation. There are costs associated with varnish removal, but the real costs are downtime and loss of production.
Gas - In processing industries, where gas is present, such as gas compression facilities, lube oil can become entrained with gas, becoming aerated and not supplying the correct oil film or strength to the lubricated surfaces, as well as reacting with other contaminants in the oil to cause varnish potential. Aeration in hydraulic equipment also causes cavitation, prematurely wearing pumps, controls and work accessories. Aeration and cavitation in lubricating oil destroys components and pumps, and reduces operating efficiency.
Moisture in oil is a common contaminant, as our climate can be humid with a wide temperature range. In close tolerance rotational equipment, moisture levels below 200 ppm are acceptable but some OEM specifications allow for much higher.
Free Water has a devastating effect on bearing surfaces, as the water droplet compresses and becomes super-heated into steam, exploding and 'etching' the bearing surface, rendering it unserviceable.
Magnified Samples (60x & 100x)
The following slides are all pictures taken by BioKem Oil Services in the last year. They show a range of contaminants in 100ml samples of lube oil from gas compressors, turbines, steam feed pumps and gearbox lube oil tanks. For reference the black line shown is 44µm in width.
RUST – The presence of water speeds oxidation and additive breakdown of the oil and is considered a serious problem. Particle size varies from 10 - 120 micron range
FIBRES - Typically introduced by improper cleaning and maintenance practices.
ASPHALTENES - particles are generally in the 0.5 - 2.0 µm range and they agglomerate into an oily sludge. This problem is made worse when free water is present.
SILICA & SAND – range of debris on this slide typically found airborne in Australia.
BRIGHT METAL PARTICLES - Typically comes from component wear. These particles are abrasive and, as a result, can lead to further wear and tear of the system bearings.
SOOT & SILT (<5µM), SILICA AND DUST PARTICLES - This is typically airborne contamination or part of sludge from the bottom of tanks. Very hard and extremely abrasive against delicate components in boundary layer systems.
Non Magnified Samples
Sludge – This is a filter housing showing a buildup of oil additives after exposure to moisture (no magnification)
Examples of Damage
The next few articles will focus on how the different contaminants are caused, and the types of resolutions that can be performed.
If you would like further information on this article or others, please let me know or visit our website.
Over the next few articles we will cover the range of issues that you should consider when managing your lubrication oil for close tolerance machines, hydraulics and gearboxes.
What you cannot see is doing the damage
Silica & Bright Metal at 100x
Let’s start with the types of contaminants:
- Hard particles, such as Iron, Chrome and other metals, Silica and sand
- Soft Particles, such as Copper, Tin and other soft metals, fibres
- Soluble contaminants, varnish, incompatible top up lubes or additive packages
- Gases and Aeration, process gases and aeration from ingression or inadequate system design
- Water and liquid contaminants that can change lube viscosity
Hard particles will score and wear away lubricated surfaces, producing other contaminants in the lube oil, creating a snowball effect of increased wear rates. Wear particles and contaminants that oxidise, will deplete the antioxidants in additive packages, leading to varnish potential.
Soft contaminants have the potential to damage lubricated surfaces and increase wear rates, as well as depleting antioxidants, plugging filtration systems and galleries.
Varnish is a by-product of contaminants or depleted antioxidants, and a real concern in any lube system as the damage caused by varnish includes sticky and gummed valves and actuators, decreased tolerances which restricts lubrication to the wearing components causing higher operating temperatures. Varnish can also plate out on bearing surfaces, causing hot spots and journal deformation. There are costs associated with varnish removal, but the real costs are downtime and loss of production.
Gas - In processing industries, where gas is present, such as gas compression facilities, lube oil can become entrained with gas, becoming aerated and not supplying the correct oil film or strength to the lubricated surfaces, as well as reacting with other contaminants in the oil to cause varnish potential. Aeration in hydraulic equipment also causes cavitation, prematurely wearing pumps, controls and work accessories. Aeration and cavitation in lubricating oil destroys components and pumps, and reduces operating efficiency.
Moisture in oil is a common contaminant, as our climate can be humid with a wide temperature range. In close tolerance rotational equipment, moisture levels below 200 ppm are acceptable but some OEM specifications allow for much higher.
Free Water has a devastating effect on bearing surfaces, as the water droplet compresses and becomes super-heated into steam, exploding and 'etching' the bearing surface, rendering it unserviceable.
Magnified Samples (60x & 100x)
The following slides are all pictures taken by BioKem Oil Services in the last year. They show a range of contaminants in 100ml samples of lube oil from gas compressors, turbines, steam feed pumps and gearbox lube oil tanks. For reference the black line shown is 44µm in width.
SILICA & SAND – range of debris on this slide typically found airborne in Australia.
SOOT & SILT (<5µM), SILICA AND DUST PARTICLES - This is typically airborne contamination or part of sludge from the bottom of tanks. Very hard and extremely abrasive against delicate components in boundary layer systems.
Non Magnified Samples
Varnish – Flakes of varnish plated out onto a filter and the varnish washed out onto an an absorbent towel (no magnification) |
If you would like further information on this article or others, please let me know or visit our website.
Thursday 9 April 2015
Has your Lubricating Oil got Gas?
Entrained gas can reduce your oil lubrication effectiveness by up to 80%
Entrained gas reduces the efficiency of your lube oil, which can have negative
consequences on the machinery it is supposed to be lubricating. This can
range
from minor consequences up to devastating effects. The longer it’s
left, the worse the consequences.
But
first, here is a description of the problem - this is about fluid
aeration, it happens at high temperature and compression rates, when the
lubricating
oil in your equipment comes into contact with gas, bubbles form in the
lube oil. When oil is aerated, it won’t give a full film, leaving
sensitive components unlubricated, causing extremely premature wear
rates or catastrophic failure.
Electrophysical Separation Process |
Before
you open a bottle of Coke or beer there are no visible bubbles, this is
dissolved gas. When you open the bottle you see tiny bubbles in
suspension - this is entrained gas. The same as in your oil.
There are several situations when this can occur even in closed loop systems.
|
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