Additive depletion

Rob, we have a simple fix for this issue. Please either call or email me with your contact info. I will be appy to provide you with an easy fix.

Jeffrey P. Chapin
j.chapin@fluitec.com
315-447-3780
www.fluitec.com

Are you using a hydraulic oil type - given the higher amount of zinc? Gear oils tend to use a sulfur phosphorous (Extreme Pressure)additive package. It could possibly be moisture from the process being ingested into the oil through the relief breather. The additives are affected by the amount of moisture/water in the oil (depending on temperature) and can drop out of the oil - I have seen this happen particularly in fixed plant processes where additives such as zinc and phosphorous start to drop out even in gears that are not under heavy load. This can happen even if you have a gear oil with EP additives only. I'd suggest improving the breather to a desiccant style one (3 microns)- this will help reduce any moisture and dirt ingression.
The other option is to install an off line filtration system.
Major oil companies also have gear oils that are designed to run with a certain amount of water in the system - these tend to emulsifier the water rather than demulse the water. See what your oil supplier has. There are also synthetic based (PAO) gear oils on the market with very little EP additives - which may help.
If you are using a hydraulic oil with zinc antiwear - I'd suggest switching to oil without the zinc antiwear or zinc free hydraulic oil - these tend to have only a small amount of phosphorous.

Hi Rob

We have noted the same with pressure relief breathers, we don't recommend their use because of the excess water we consistantly find in drives fitted with pressure relief breathers,
we think it's because the increase in pressure in the drive increases the boiling point of any moisture in the system preventing the water from boiling off,
The excess water is polar as the chemistry is in your floatation circut and once in the drive the two will be readily combining and as you have noted (well done) deplets the lubricants additive package.
It's said it costs 10 times more to remove a contaminate than to prevent it's entry,
so we would check out whether it's practical to fit a bladder bag breather system to the drive and because water and "fumes" are gaining entry likely particles are too so should provide a significant improvement in reliability as well,
We have been researching and trialing breather systems on drives over the past 6-7 years and there is no doubt, a bladder bag breather system prevents all contaminates from gaining entry, (Bag life about two years) email us on lab@rttech.com.au for an easy do it your self bladder bag breather system plan that will prevent this from occurring.
Then lubricant can remain the same and with drives, particle count and PQ are the relavent monitoring, if particle counts trend at an ISO 17/14 and PQ trends 15-25, we would not find any significant debris when checking by microscope.


Regards

Rob S

www.rttech.com.au.