Emulsified Water in Oil

It has been my understanding that emulsified water is a threat to the health of equipment in several ways. First if there is enough water to form a cloud them the humidity inside your equipment is going to cause surface rust to form and will contaminate your oil with red oxides which are abrasive in nature and contribute to excellerated wear. Second if in a gear train when the emulsified water is carried into the load zones the momentary extreme increase in pressure with accompaning increase in temperature will cause the water to flash into steam which will blow away any oil film, and work its way int any subsurface cracks causing hydroogen embrittlement which will cause pitting along the pitchline on gears of contact path in rolling element bearings. Water reduces the lubricants surface tension and ability to adhere to the surfaces.
These are just a few of my thoughts. I am not an engineer and this refelcts my reading of the literature available and field observations.

Another couple of points to add to BuckHntr's great response...

- Emulsified water will increase the viscosity of the lubricant.
- The film strength of the lubricant is weakened.
- Emulsified water can cause "additive washout", quickly depleting the additive system. Sometimes, water will react with an additive package to form a precipitate.
- Water is a catalyst for oxidation.

There is also evidence that even dissolved water can impact the life of bearings. Theories abound in our industry because it is so difficult to know exactly what happens inside a lubrication system. Be sure not to implement any theories unless it is backed by science and research. There...off my soapbox for now.

My one cent to your queries ,Chris

We must understand that contamination is a "Silent Killer".

Second , all additives used in lubricant system are oil soluble, which means that water is not accepted in the system.

Once water enters the system in any form ,it will react with the additives and on hydrolysis forms acids and precipitates which cause lubrication failure syndrome in the machine.

Hopes that's adds light.

Franky

Just to complement Greg´s post:
According to a SKF study, "bearings can lose 75% of life due to water before oil is cloudy".
"Claudy" means in some cases up to 0,1% of water.
I like to repeat every time I can my favorite quote:
"Be cautious (take care) of the disolved water, if you have emulsified or free water you are in really big problems"

Oil & Water: Three types: 1) Dissolved water in oil. NOT VISIBLE! Water will only dissolved in oil to a slight degree. This is best detected by Karl Fischer Coulmetric Titrators. The warmer the oil the more water that can be dissolved in the oil up to saturation.

2) Free water. The is water that settles to the bottom of the tank or reservoir. It can also be seen as drops of water hanging from the underside of the oil reservoirs (many reasons for this but too detailed for this quick post.
This water generally WILL NOT BE SEEN OR DETECTED by the lab unless the sampler takes a sample of oil from the lowest point in the systme. Also free water can exist in a system as droplets on the inner surfaces of pipes, tanks, etc. The risk of free water in a system is two fold. 1. As the oil heats up during operation the free water is the reservoir causing an increase in "Dissolved Water" in new oil. 2. Rust and other oxidization products of the oil will be seen at these points upon an internal inspection.

Emulsified water in Oil:
This occures when Free Water and Hot Oil are AGITATED togather. This is major issue since it proves that you not only have a high amount of free water available but that the Dissolved Water exceeds the saturation point of the oil. This causes high amounts of water to be distributed thoughout the entire system and deposited in dead flow areas. Hot water and hot components will degrade those componets.

Other notes:

Dissolved water: Can never be totally eliminated. Only detected reliably by Karl Fischer Titration. The Hot plate test will only give a positive test for super saturated oil. Thus the hot plate test is a very poor and outdated testing the quality of your oil for water.

Free water: The reservoir of water that can lead to saturated oil if the oil is very hot or emulsified oil if this free water is in an area where agitation of Hot Oil and water will occure.

Several ways to determine if you have Free Water in your systme:

1. The ppm of dissolved water determined by Karl Fischer Titration will continue to increase after adding new oil or filtering out the water.

2. Take a sample of HOT Oil from the lowest point in a GLASS BOTTLE. Let the oil in the bottle cool to room temp. Look on the inside of the glass bottle for what appears to be "bubbles" that form and continue to enlarge. This is the excess water, beyond saturation, that plates out on the side of the glass as the oil cools. Remember hot oil will hold more water in solution (dissolved) that cold oil.

Hope this short note helps in further discussions.

Mel

Let us remember that viscosity is one of the most (if not THE MOST) important characteristic of an oil used in almost all lubrication regimes. In general, presence of water in free or emulsified form has a detrimental effect on viscosity, additives, and the equipment (as noted by BuckHntr, Greg, Franky, and Mel). For example, any amount of water in oil carried in a hydrodynamic lubricated system (e.g., plain bearings) will cause starvation of lubricant in the equipment (proportional to the amount of water). As a result, a) temperature of the oil film (now thinner) will increase; b) rubbing of the aspherities (wear) will increase; c) higher temp will increase water evaporation rate resulting in increased hydrogen embrittlement (as noted by BuckHntr) and promote greater wear rate. This is a vicious cycle, where things quickly go from bad to worst. Luis’s favorite quote nicely sums it up "Be cautious (take care) of the disolved water, if you have emulsified or free water you are in really big problems".

John

quote:

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Originally posted by Chris Wiberg:
We are currently having a debate over the effects of emulsified water in a lubricated system. One theory has been proposed that emulsified water is "hidden" as very small droplets within the continuous phase. Thus, water which is emulsified as droplets in the oil never directly contacts any part of the lubricated system and can therefore not cause damage. The other theory of course is that emulsified water does cause damage to the lubricated system. The second part of our debate is that if the water is acidic will it manifest its acidic properties (i.e. be corrosive)when emulsified? We are seeking input on whether or not damage will occur as well as on proposed mechanisms for such damage.

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First, let me say that I agree that water in oil is not a good thing. But I would like to share an experience at our facility regarding this issue. We have two 250 HP homogenizing pumps that deliver slurry to our process. If the pumps are operated with leaking packing, the crankcase will be contaminated with water and slurry. This typically happens once a month. The combination of lube oil, water, and product produce a "milk shake" like solution. A pump may run for days before the contaminated oil is replaced. These pumps have operated 24/7 under these adverse conditions for 10 years without any major mechanical repairs. The factory technician has inspected the bearings, gears, crankshaft, etc. without significant findings. These pumps have been able to survive under these adverse conditions. This is not the way to operate and we are taking corrective actions. I just wanted to share this information on the topic.

I have experienced the "milkshake" of emulsified oil & water in a tractor transmission. I have drained the mixture, but there is some residual mix remaining on gears and most any other surface that is not vertical. Is there a product or method of removal that anyone can recommend? Access is gained through an opening approximately 7"x9", so something could be poured or sprayed in and drained out, but there is no way to split the case to gain access to wipe off surfaces, gears, etc. I had considered refilling (~3.5 gal.), running the tractor for awhile to distribute and dilute the mixture with the new oil, and then re-drain and remove the access cover while hot to see if evaporation would then take care of the rest. Any removal product or removal method suggestions?

jodyinia,

The steps that you are considering (rinsing with new oil and refilling) are correct under the circumstances. Additional step for you should be to prevent further water ingression by re-checking possible “culprit” areas (e.g., access cover, dipstick area, etc.). Adding an off-line absorbent filter (e.g., cellulose fiber filter) to your sump may not be economically advantageous because of the amount (miniscule) of oil in your sump.

I happened across these posts seeking answers to questions. In my wanderings, I read some very good articles (I be more edikated now) on the subject of oil and emulsifications. On point brought up was that, under extreme pressure, water could break down into its component parts. Subsequently, the hydrogen would absorb into the bearing surfaces and result in brittle bearings.

That aside, what would the effect of putting a minor vacuum on your transmission? My [ignorant] guess is the water would be the first to dissapear. Any compressor would serve (I made the wife a vacuum sealer out of a garage sale nebulizer by merely popping the cover and swapping the hoses.

Its been my experience that emulsified
oil/water stimulates the economy keeping Shell/Mobil/Texaco etc in business and also paying to dispose of the mixture. There is also a health/safety risk for those who are exposed to the mix as water/oil promotes an environment for highly infectious bacteria-almost lost a working partner to this bacteria several years ago.

Tom

I wish to join the anti-water fraternity.
ANY water is detrimental to the systems.(for the reasons as noted by John,BuckHntr, Greg, Franky, and Mel).
Those tolerating water conntamination have usually been designed with water contamination in mind. Many test suites look for water by
FTIR and crackle reporting no water when in fact there is potentially up to ~1000ppm and 500ppm respectively. For sensitive systems Karl Fischer or similar is essential to see exactly the amount of water present and to then take remedial action where necessary.

I cannot add any new information to what is already posted, however, there is a very interesting article published by kluber that shows the effects of water contaminacion to glycol based lubes and the increase in protection that it provides. Of course, it is RELATED to GLYCOLS, not mineral oil.

By the way, i am not related to kluber in any way.

"Water-Soluble Polyglycols for the Lubrication of Large Gear Drives"


h**p://www.klueber.com/PDF_anzeigen.cfm?pdf=KLUSA_Polyglycol_version.pdf

Hi Chris

Note how all in the "discussion group" think the water should be removed from the lubricant,

As Mr John Micetic noted,
Viscosity change under load is the area where damage can rapidly occur, the lubricant molecule is complex and resists flow giving viscosity, the water molecule is simple and has no ability to resist load,
So in a rod mill if the rolling element tapered roller thrust bearing receives a shot water instead of oil, there is a catastrophic failure causing shut down, we have a good image of this damage if anyone would like to see pop us an email lab@rttech.com.au
Chris it appears the discussion group think the cost of keeping the water out or removing the water will far less than the cost of the damage the water will cause to your application and the lubricant in use.

Ariel, thanks for that link, worth a read


Regards


Rob S

Dear Chris,

All Ferrous components "rust" in the presence of water/moisture and air, a process we call oxidation. This is compounded by temperature, pressure, acidity etc..

This means that water/moisture ingress will cause incipient corrosion on Ferrous metals. Thus water/moisture is a threat to any equipment having Ferrous.

Hussam

I agree that no water is desirable in any mechanical system. Presence of water will have a number of detrimental effects. From lack of lubrication at the load zones to the production of acids in the oil in the presence of oxygen. Moisture is particularly detrimental in refrigeration compressors and any system with very small tolerances. But as a rule of thumb, water is a definite undesirable contaminant.

There are a couple of ways to tackle water in oil.

1. If possible, use a marine lubricant that is made to perform well in the presence of up to 10% water such as http://www.amsoil.com/storefront/agm.aspx?zo=1181889 .

2. Another approach would be to use an oil that phase separates the water and drain off such as a compressor oil. Here is a brochure: http://www.amsoil.com/lit/g1310.pdf .
Here is a study comparing different brand compressor oils and resistance to acidity, corrosion, oxidation and how well they demulsify. http://www.superoilcentral.com...sor_white_paper7.pdf