Reconditioning of EH oil

A 1200 MW coal-fired thermal power plant using Indo-Chinese turbine EHC system in southern India.

Synopsis
The plant was struggling with the rapid increase in TAN values in the EH oil of the governing system of the turbine.

Reconditioning of EH oil

A 1200 MW coal-fired thermal power plant using Indo-Chinese turbine EHC system in southern India.

Synopsis
The plant was struggling with the rapid increase in TAN values in the EH oil of the governing system of the turbine. Also, the moisture content was more than permissible limits. Degradation of the oil was due to contamination ingression into the system resulting in by-product formation.

Minimac’s EH oil reconditioning system “MLC LVDH TRIX 20” proved to be the savior and an unexpected shutdown of the turbine worth ₹1.05 Cr per day was saved.

Problems
A rapid increase in the Total Acid Number (TAN) could degrade the EH oil and lead to the possibilities of failure of servo valve, hunting, power generation loss, unplanned shutdown, etc

Oil analysis was done to check the properties of EH oil like moisture, NAS value, total acid number.

Solutions
Installation of Minimac’s EH oil reconditioning system “MLC LVDH TRIX 20” comprehensively designed with 4 major technologies to:

Remove solid contamination from oil by Superfine filtration

Remove moisture from oil by vacuum Dehydration technology

Reduce Total Acid Number (TAN) by Ion exchange technique.

EHC system tank moisture removal and ingress prevention by Inert Gas blanketing technique.

Along with equipment installation, our service engineer trained the customer’s team on the functions of the EH oil re-conditioner, FRF maintenance, contamination control, and importance of the oil analysis program.

Cost Saving
This plant managed to save:

Cost of oil replacement: ₹60 Lakh approx.
Cost of downtime: ₹4.2 Cr approx
CO2 e Saving
14,400 kg of CO2 e / 0.0144 gigagrams of CO2 e

Benefits
Extending oil life.
Eliminate oil Replacement cost.
Protect Turbine against hunting.
Increased Turbine reliability.

The below graph shows the trend analysis of tracked values during the reconditioning of EH oil at Unit #2

Total Consumable Details
Filter - 01 qty of 10 - microns
Filter - 01 qty of 3 - microns to achieve NAS 5 cleanliness
Total resin - 60 liters

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Success Story: A small change can bring a Big Difference

Do you agree that the little things, if done consistently, add to the big things? The same applies to every field of life, whether it is personal or professional. The very recent example recites

Success Story: A small change can bring a Big Difference

Do you agree that the little things, if done consistently, add to the big things? The same applies to every field of life, whether it is personal or professional. The very recent example recites it very true. The whole story begins with an opportunity to supply and commission 8 numbers of Oil Quality Testing Equipment for a sector that is crucial regarding the nation's safety. It was a great experience to work with the best brains and brave hearts.

We started our journey from Pune to a remote location in Odisha, Koraput. When we landed at the nearest airport, we knew it was more than a 5-hour journey by road, crossing many hills, valleys, forests, and ghats. During our travel, we encountered many wild animals and, surprisingly, snakes like pythons crossing the road. Probably, high wind and rain were making it more scary and adventurous. We arrived at our stay very late at night. After such a long day, we were excited to hit the bull’s eye the next day.

We couldn’t resist the enthusiasm and reached the plant before the time the next morning. We were very happy to see the grand welcome following intense security protocols. The industry can be classified as Defense & Space. A division regularly conducted workshops for the customers to better understand and utilize the products.

We showed our advanced Oil Testing Equipment, LPA3, but a few officers were not confident enough about the deliverables. The technology they used then was outdated and failed to meet the latest standard. We had to install, commission, and demonstrate 8 particle counters at different locations and in different machines. We did it within 10 working hours, which was an achievement in every sense. Along with the demonstration, we made them understand the minimum human intervention and the impossibility of tampering with our oil quality testing equipment results. As they were following traditional practices, this technological advancement was much needed in their plant, and it was about to bring a big difference. We did our best in the least time. The company officials were really happy & fulfilled and so were we. It was a great experience, and a perfect example of a small change can bring a big difference.

Best practices for maintenance of FRF in turbine EHC systemWhat is a Turbine EH System ?
Electro-Hydraulic Control system (EHC system) of a turbine is the most critical equipment of a power plant. It’s the heart of a turbine which controls steam flow

Best practices for maintenance of FRF in turbine EHC systemWhat is a Turbine EH System ?
Electro-Hydraulic Control system (EHC system) of a turbine is the most critical equipment of a power plant. It’s the heart of a turbine which controls steam flow into the turbine. A malfunctioning EHC system can lead to turbine stoppage and thereafter create a dominoes effect on the synchronized processes of the power plant. Breakdown-free and reliable operation of the EHC system is the biggest challenge of an Operation & Maintenance Manager. To learn more follow:
https://www.linkedin.com/company/minimacsystemsprivatetlimited

Due to high steam pressure & temperature in the vicinity of a steam turbine, as safety compliance, it is a mandate to use Fire Resistant Fluids (FRF) for hydraulic control of the EHC system. A specially designed synthetic fluid called tri-xylenyl phosphate ester demonstrates best fire resistant properties for the application.

Phosphate esters are polar fluids with excellent lubricating properties that can operate under extreme conditions.
However, phosphate esters require strict control in order to extend their useful lifespan.

Water and Acids de-grade FRF
Phosphate esters (which are being used as FRF in EHC systems) are manufactured under controlled environment through the esterification of phosphoric acid, where water is a by-product.

Phosphoric Acid + Alcohol → Phosphate Ester + Water

Unfortunately, phosphate esters are highly hygroscopic (tendency to absorb water) in nature and the esterification process is reversible when phosphate esters come in contact with water. This is referred to as hydrolysis. The higher the water content and temperature, the faster the ester will break down by hydrolysis.

Phosphate Ester + Water → Phosphoric Acid or Acid Phosphates + Alcohol

Thereby it is recommended to control the water level, temperature, and acidity in FRF of the EHC systems. If uncontrolled, the acidity accelerates rapidly.

TAN value or Total Acid Number (measured in unit mgKOH/gm) is a parameter to denote acid content accumulation in FRF. A high TAN value degrades the fluid rapidly, decreases its viscosity and resistivity. Thereby causing acid corrosion of sensitive servo-valves and other system components of an EH System.

FRF de-gradation due to particles
Water and acid are not the only contaminants which can degrade the FRF.

Since the dynamic oil film and fine clearances in servo-valves are less than 5 micron, even the finest silt particles and sludge/varnish deposits from fluid degradation can hinder proper operation. Fine particles get trapped in clearances between the valve plunger and housing. This abrasive wear is known as seizing or grinding. This can result in wear rates that are a thousand times greater than anticipated by the valve manufacturer.
Therefore, it only makes sense to use very fine filtration (3-5 micron) for maintaining the EHC fluid. For any Technical Consultancy Call - +91 89751 50700

Consequences of FRF de-gradation

Acid, gel and sludge/varnish formation
Valve sticking or blocking
Reduced lubricity and film strength
Corrosion, erosion and abrasion wear
Reduced fluid resistivity
Soot generation (entrained air)
Short fluid life
The result is poor EHC system reliability and reduced turbine availability.
Condition based monitoring of FRF
It is highly recommended to carry out regular fluid analysis of FRF and identify any abnormalities in the trend for further preventive actions. Recommended parameter values for FRF:

Parameter unit value
Appearance ASTM colour code clear, < 3
Water content ppm 500
Kinematic Viscosity (@40 0C) cSt 41-45
Acidity (TAN) mgKOH/gm < 0.15
Particle contamination code ISO 4406 15/12
Cleanliness code (NAS-1638) NAS 1638 5

To learn more follow https://www.linkedin.com/company/minimacsystemsprivatetlimited

The Minimac FRF Re-conditioning System comprises 4 major steps, all packaged carefully in 1 single skid.

Solid contamination Super-fine Filtration
Moisture in oil separation by Vacuum Dehydration technology
TAN reduction by Ion Exchange technique
EHC system tank moisture removal by Inert Gas Blanketing technique
Would love to have your feedback, experience, query.. Got any question? Ask away!!

Is Overgreasing Dangerous?

Greasing is an important process that ensures the smooth functioning of machines. Let’s understand these two aspects first - Overgreasing and Undergreasing. To determine which of these is more problematic could be difficult

Is Overgreasing Dangerous?

Greasing is an important process that ensures the smooth functioning of machines. Let’s understand these two aspects first - Overgreasing and Undergreasing. To determine which of these is more problematic could be difficult but we can definitely decide which one is more damaging. Too much grease can generate excessive heat in the bearing and may result in seal failure. When the lip seals rupture because of over greasing, it allows the harmful contaminants to enter the bearing housing. This would create excessive pressure and may collapse the bearing race. On the other hand, not putting enough grease may cause damage to the rotating parts. Undergreasing allows contaminants to enter the load zones. We can say that it's better to avoid both aspects of over and under greasing.

How to determine the amount of grease a bearing needs?
The factor responsible for determining the right amount of grease depends on the dimensions of the bearing or its housing. Greasing must be done based on proper calculations. A formula that is used commonly is as follows:

The outside diameter of the bearing is multiplied by the width (in inches), then multiply the answer by 0.114. This would give you the amount of grease in ounces required for that particular bearing.
For example -
If the outside diameter of a bearing is 3 inches and the width of a bearing is 0.5 inches, then
3 X 0.5 = 1.5
1.5 X 0.114 = 0.17
Thus, The amount of grease needed is 0.17 ounces or 4.8 grams.

Still not sure how? Connect with our experts: Click here

How to solve the problem of Overgreasing?
After having a grip on how much grease to put, try to master the frequency. Take help from various tables and charts available for determining the frequency. Calibrating the grease guns could be a simple and easy step to determine the correct volume of grease. It is very important to discontinue greasing when any abnormal pressure is encountered. Manual grease guns used in the industry have a few disadvantages. The poor control of grease guns may lead to over/under lubrication. Because they are low in cost, easy to use, and allow the technicians to inspect the equipment during the tasks, industries prefer using manual grease guns.

Setting up a maintenance program could be a game-changer. Keep a track of each grease point and schedule maintenance & inspections for the same. Initially, it may take some time and effort but the end result would be great and impactful.

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Common mistakes of Oil Sampling and how to avoid them?

Routine Oil sampling and analysis are crucial for a successful maintenance program. It provides important information to determine the condition of the equipment. Sampling is a vital procedure for

Common mistakes of Oil Sampling and how to avoid them?

Routine Oil sampling and analysis are crucial for a successful maintenance program. It provides important information to determine the condition of the equipment. Sampling is a vital procedure for collecting fluid from machinery for the purpose of oil analysis. The results and reports of oil analysis depend on the quality of the oil sample.

Thus, oil sampling must be performed keeping some important goals in mind -

To MAXIMIZE the Data Density.
To MAXIMIZE Consistency.
To MAXIMIZE Relevance.
To MINIMIZE Data Disturbance.

There can be three ways of extracting samples from a component - drain port, drop-tube (in a vacuum pump), and a dedicated sampling point. A common mistake is taking an oil sample from the reservoir in circulating and hydraulic systems. Taking samples from the tank is not a best practice. If the sample is taken from the drain lines before emptying the tank, the concentration of wear metal would be much higher.
Let’s discuss the common mistakes of oil sampling which can be avoided -

Some sampling methods are simply used for convenience, like inadequate flushing, using a vacuum pump (drop-tube sampling), usage of uncleaned bottles, etc. By following these bad practices, the quality of the sample taken is not apt and reliable.

If the samples are collected from the bottom of the tank and sumps, they may show higher concentrations of the sediments and water.

If the samples are consistently collected from the turbulent zones of reservoirs and tanks may not give reliable information.

Sometimes the sample is collected consistently from downstream of pressure-line or off-line. In this case, sampling accuracy is not given importance.

Samples collected from cold systems would not give correct information as the contaminants and other insoluble suspended particles would be settled when at rest.

Dead zone fluids like standpipe, regenerative loops, etc. give wrong results as they possess different properties than that working fluids.

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The International Organization for Standardization (ISO) has some defined codes which are mostly used as the primary reviewed piece of data. Being consistent is important with sampling. It is not advisable to use different sampling methods. Let’s discuss certain must-follow sampling rules for oil analysis -

Collect samples from running machines not from cold machines or stand-by machines. It is always advisable to start the machine and take the sample and the time of sample should be when the machine is at its peak of stress.

What, when, who, where, and how should be defined for oil sampling procedures as well, just like maintenance procedures are defined in detail. Changing the sampling methods or location is not advisable.

Use a specific sample point based on the type of lubricant, pressure, and the fluid required.

A sample must be taken in a bottle of the correct size and cleanliness. To get more information on bottle cleanliness, ISO 3722 can be referred to.

Oil sampling is like examining the condition of the system for that point in time. It is advisable not to wait for more than 24 hours to send the samples for oil analysis. This is because the health of the system may change in a very short period. Early detection would help in early remedy.

Maintain proper frequency of taking samples. Don’t do it whenever you feel like doing it. There should be an appropriate frequency so that important maintenance decisions could be taken on time.

One of the major problems in oil sampling is cross-contamination. Don’t use dirty sampling equipment. Flushing is the solution to this which is often overlooked and the selection of suitable clear media is equally important.

Though every system has a unique consideration of sampling, the above-mentioned tips can be applied and taken care of for your sampling techniques/methods. Start applying it Today!!

Connect with Minimac Experts to strategize your Oil Analysis plan: enquiry@minimac.in or WhatsApp us at +91 70309 01267

Are you trying to make your oil look better than it is?

Oils are used to reduce friction, heat and wear between mechanical components that are in contact with each other. Lubricants are like the blood of your machines. As blood sampling represents the

Are you trying to make your oil look better than it is?

Oils are used to reduce friction, heat and wear between mechanical components that are in contact with each other. Lubricants are like the blood of your machines. As blood sampling represents the well being of a human body so does the lubricants in case of machines.

However, a wrong sampling technique might not reveal the true condition of the machine and thus, leads to the wrong representation and pre-mature breakdown. Thus, MINIMAC SYSTEMS is starting this know your oil series under which we will make you aware of:

How to collect a sample
Type of contaminants and how they are harmful for your machines
Oil analysis and how to decode it
Oil changes are mostly done under two conditions:

On the basis of time or operating hours
On the basis of oil condition
Most of the time, changing oil based on time or operating hours is expensive and hence, changing based on oil condition is more viable. At this juncture, an Oil Analysis Report is key to decision making. For accurate oil analysis, correct sampling is the pre-requisite. For queries related to Oil Testing:
https://www.linkedin.com/company/minimacsystemsprivatetlimited
3 points to be considered while taking sample:

TURBULENCE: The best sampling point is the place like sharp elbows or bends where the oil turns a lot and thus, carries a lot of impurities. The point which are located where the flow is laminar tends to have lesser particle carrying tendency and as a result, makes the oil appear cleaner than what it is.
INGRESSION POINTS: Oil samples should be taken downstream of parts that have a lot of wear and tear and before the oil gets into the inlet to the main oil tank. As once the oil gets mixed with the rest of the oil, the contamination gets diluted and results in poor sample.
FILTRATION: Inline filters ensure that they provide cleaner oil to the machinery downstream of them. If a sample is taken downstream to the filters it will be a lot cleaner than what the actual sample is until unless the filter is not working and is in the by-passed condition. Hence, the sample at all times should be taken upstream to the filters.
When a true representative sample goes for oil analysis it can give answer to the following questions:
(Call +91 8975150700 to book an appointment)

Whether the oil is suitable for further use or requires filtration, dehydration/flushing?
What are the types of contaminants in the oil? Are they in the limit as per ISO standards?
What is the condition of the rotating part? Is there excessive wear and tear?
Are there problems like Sludge/Varnish developing which requires flushing of the entire system.
Get your machine's oil check today with our technical expert by clicking on https://www.linkedin.com/company/minimacsystemsprivatetlimited or call +91 8975150700.

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Minimac's step towards a Sustainable Future - Earth Day Special

As Wendell Berry once said, "The Earth is what we all have in common." Earth Day is the only secular festival on the globe. This celebration aims to thank mother earth for nurturing us and

Minimac's step towards a Sustainable Future - Earth Day Special

As Wendell Berry once said, "The Earth is what we all have in common." Earth Day is the only secular festival on the globe. This celebration aims to thank mother earth for nurturing us and giving us all it has. People swear to plant trees, restore the earth, and not exploit the environment. Every year we see many initiatives taken to save the earth on this day but do we really achieve it? Now we need to measure the changes after taking specific steps. From a recent survey, we can see that ten out of the 15 most polluted cities in the world are from India.

It has not been six months since all the heads of 197 countries attended the COP26 in Glasgow, Scotland. The primary concern of the billion-dollar event was to maintain the earth's temperature. As the theme of Earth day for this year suggests, ‘Invest in our Planet’, we need to invest instead of paying later for getting fresh air, pure water, organic food, etc.

Do you know Contaminated oils are very harmful to the environment? There are two aspects to this. The exploitation of natural resources to get new oil and the Disposal of the used oil. As we know, lubricants come from limited reserves. Exploiting natural resources has significant environmental impacts, causing irreversible damage to human life.

According to Oil Care, just 1 liter of oil can contaminate 1 million liters of water. Oil pollution has a devastating effect on the water environment if it spreads over the surface in a thin layer that stops oxygen from getting to the plants and animals that live in the water. Unfortunately, it all applies with lube oil too.

Why not reuse the oil? Reusing can bring great benefits to the environment. Oil reclamation is an environmentally friendly process that involves filtration, dehydration, and readditization to recover the properties of the lubricants and extend their useful life.

Learn how you can save Earth by reusing Oil: Click here

We should invest in spreading awareness to bring the change. We, at Minimac, working towards bringing a markable change to nature. Fortunately, we work in cleaning, filtering, and reconditioning oil. We filter tons of lube oils in a year. Recycling and reducing impurities in lubricant not only reduces the operating cost of a machine and increases its productivity but also contributes to saving the environment.

Minimac Systems over the years has become equipped with almost all the technologies which are required for contamination control in lubricants. As a part of its sustainability strategy, the company focuses on the fast development of future technologies based on the dynamism of the industry and the anticipated changes. On this earth day, let’s pledge to reduce the negative impact on the globe.

Types of water contamination in oil

Team Minimac

Feb 24, 2022 · 2 min read

In our last #knowyouroil segment, we had discussed about Particle Contamination and its effect on the life of rotating parts. Companies spend a lot of money on installing

Types of water contamination in oil

Team Minimac

Feb 24, 2022 · 2 min read

In our last #knowyouroil segment, we had discussed about Particle Contamination and its effect on the life of rotating parts. Companies spend a lot of money on installing filtration units to counter particle contamination but never take preventive measures towards water contamination. Water is a worse and silent killer for the life of machinery as it slowly degrades the oil properties and one only gets to know about it when the machine fails pre-maturely.

In this article, we will try to understand the basics of Water Contamination. We will also try to answer the following questions.

What water does to oil properties?
Can we see water contamination as soon as it starts?
What to do if our oil is contaminated?

To check your machine's, follow: https://www.linkedin.com/company/minimacsystemsprivatetlimited There are three phases in which water can exist in oil i.e. dissolved water, emulsified water, and free water.

Dissolved Water: It is characterized by individual water molecules dispersed throughout the oil. Water can remain in a dissolved state and hence difficult to understand the contamination at this stage.
Emulsified Water: When the oil gets saturated with water it starts to exist as a suspension in oil like microscopic droplets giving oil a milky appearance and is called emulsion.
Free Water:When the level of oil in water increases further it leads to separation of oil and water called Free water.
For a lubricant, the most important property is its viscosity. As the water starts to mix with lubricant it starts to alter the viscosity and hence impacts the film strength which is essential in maintaining equipment reliability by keeping moving parts away from each other. Water contamination also impacts the chemical properties of the base oil by acting as catalyst oxidation and aeration. This also leads to the appearance of sludge and varnish which leads to premature failure.

Water contamination also leads to Hydraulic Pump Cavitation in machines: Pitting inside of the machine; as the water droplets burst under pressure and high temperature creating microfractures on the machine’s surface.
If you see the signs of water contamination in your oil, what should you do?

Not to change oil as changing oil is not the only option. This is because once the oil is drained the impurities still remain in the system until they are flushed. If new oil is introduced without cleaning the system it leads to contamination of the new oil leading to no change in the premature breakdown situation.
Flushing of the system
Check the internals of the system to check for any damage
Filter the new oil to ensure no moisture is available in the oil
Skip all four steps and call Minimac (+91 7030901266)

We at Minimac Systems Pvt Ltd. not only design a maintenance schedule for the lubrication oil but also provide OIL TESTING and FILTRATION services as per the ISO standard of Super Clean Oil. Minimac stands for MINImum MAChinery Maintenance.