Power Transformer Oil which type I have? Mineral...

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curiousjerry

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Hi, would someone shed some light on this for me.
I was wondering if there is a easy way to tell if my Power Transformer is filled with Mineral oil or Silicone oil?
It's not listed on the Transformer nameplate and I could not locate it in the manufacture instruction book.
I think they forgot to add it to the nameplate. It's from 1986 Westinghouse I believe.

I read silicone oil is clear and mineral is slightly yellow it's even in another instruction book for newer equipment.

But is there a sure way, I guess would have to send it to a lab to get tested?

Any help greatly appreciated.
Sincerely,
Jerry
 
Maybe others will chime in, but if it were Silicone I think it would say so on the label.

I'm not sure silicone transformer oil was even an option in 1986.

If mineral oil was the only commonly available transformer oil back then, it explains why the label doesn't mention the type of oil.
 
That's what I was leaning towards too, but in the very same contract book, it mentions both mineral, FR, and silicone oil, so it had to be an option. We sampled the oil back in 2014 and I believe it was yellowish. My boss wants to know because they plan to replace the oil with the FR oil and he said it won't work well, if it's silicone but if it's mineral then it should be ok.
Thanks for your input very much.
I would attach some images here but I don't see how to....
 
I attached some more info, but is durabil an oil or insulator for the windings a varnish perhaps? It's on a black sticker on transformer.


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Agree with synchro above…
I would expect to see above ~230 for flash and greater than 300 for silicone oil
 
And some of those test standards are specific to petroleum products.

Silicone oil is not a petroleum product, is it?
 
jyi The lab that does the testing for the oil samples for us, always does the same tests regardless if it's a silicone or mineral oil.
I don't believe silicone oil is a petroleum product, made from synthetic chemicals according to EPA.gov website.

Now we use a different vender SGS. They do even less tests seems like. Perhaps my company should be requesting specific tests based on the type oil, not sure like you said, but they don't do it like that...
 
It appears DURABIL is a Westinghouse trademark name for their type of winding insulation, nothing to do with the insulating oil:
https://alter.com/trademarks/durabil-73344828
As for the type of insulating oil I would rely on SGS to give you that info since the oil may have been changed from the initial installation.
If they can't help then contact the vendor SD Meyers.
 
Thank you for the further info ATSman. We might take another sample before the equipment goes under contract, replacing old High Tension Switchgear and replacing the oil in Transformer, it's still far from happening I imagine. But it doesn't appear to be silicone oil in the Power Transformer as Hv&Lv and Synchro mention the flash point would be higher. As long as it's not silicon oil, should be good, definitely would like to know for sure, if it was replaced at all point, so many people have retired and long gone, who knows. I will mention to management about SD meyers if they don't know already? Appreciate very much all the info, currently my company is trying to replace some of the heat exchangers for the transformers (that are water cooled) way past life expectancy which are made by Unifin with a vendor called: https://www.ryanequipment.com/ very pricey....
 
HYDRAULIC oil guy here; your 0.89 SG SUGGESTS petroleum oil. The 0.30 neut value scares me and SUGGESTS there has been, lots of water in the oil, either dissolved or free. Present water content is reasonable.

I don't know if the interior is accessible, but I would recommend professional cleaning and examination before/after.
 
I've been suggesting the oil filtering for a while now, it's something my company needs to improve on. I know the oil sample results that come back from some of these transformer, are really not good, and the oil is so important, the transformers are really being negatively affected by this poor practice, we have in place. Thanks GeorgeB for your help as well/info.
 
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