hydrostatic oil

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Emfinger
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Location: Yucca Valley, CA

hydrostatic oil

Post by Emfinger »

I have been using a 600 wt oil made by Vacuum oil company. I just discovered it is mixing with the water....not good. I can't seem to find a steam oil for use in a "hydrostatic oiler". Most of the oils I have found do not list "hydrostatic oilers"
Thank you for any help
Tom
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gwrdriver
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Re: hydrostatic oil

Post by gwrdriver »

Might be bad, might not. There's no way for us to tell what you mean by "mixing" exactly, but a proper steam oil (usually labelled by petroleum companies as "steam cylinder oil") will mix, or specifically, form an emulsion with steam and condensate.
If you use a proper steam cylinder oil of around ISO460 you'll be just fine.
Last edited by gwrdriver on Mon Jun 29, 2020 4:28 pm, edited 1 time in total.
GWRdriver
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jcbrock
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Re: hydrostatic oil

Post by jcbrock »

We always used the same steam cylinder oil we were using in the mechanical lubricator.
John Brock
James Powell
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Re: hydrostatic oil

Post by James Powell »

So, oils like TK460 (Chevron) will mix with water- that's the point of them being a compounded cylinder oil.

Oils like Mil-L-357 (Steam _turbine_ oil) don't form emulsions with water, and are used in applications where there will be condensation into the oil, and you want good separation properties. This would be the case for example, on an enclosed crank high speed engine, with the crankshaft oil. (or in a steam turbine gearbox, used for the bearings on the turbine and the gearbox oil as well...)

However, cylinder oil should mix with the water- it should float on the water in a displacement lubricator, and emulsify with the steam downstream, or be pumped and mix with the steam if using an oil pump.

James
Emfinger
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Re: hydrostatic oil

Post by Emfinger »

When using a displacement oiler the drain should only drain water...not chocolate milk. That is what I mean by mixing......water and oil don't mix...
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gwrdriver
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Re: hydrostatic oil

Post by gwrdriver »

I suspect that "mix" is the troublesome part here. Let's throw out that term because it's a chemical fact that oil and water don't "mix." We all know that. What it does (in a hydrostatic lubricator), as I said earlier, is form an emulsion.

An Emulsion is a mixture of two immiscible (non-mutually soluable) liquids where one is temporarily contained as droplets in suspension in the other. In a hydrostatic lubricator, steam cylinder oil in very hot water (condensate) often ends up in the form of tiny particles in suspension in the reservoir, hence the chocolate milk, which I would call froth. I suspect this froth is created by the pressure variations in the lubricator in the oil-water emulsion which doesn't make it into the steam line. The steam oil hasn't actually "mixed" (as in a "solution' such as paint and its thinner), and won't, but it's in microscopic suspension, and if left to stand and cool your chocolate milk will eventually separate into two discreet layers, of water and oil.

Generally speaking the live steamers I know who run with hydrostatic lubricators (typically Gauge 1 and 2.5" gauge) extract any water and froth in the reservoir each time the lubricator needs to be refilled. The chocolate milk is a part of the process. I would however want whichever oil I used to behave like steam cylinder oil. It's made the way it is for a reason. Get yourself some ISO460 steam cylinder oil and don't worry about the froth.

I have a couple of "extractors" for removing oil and water where there is no drain. One is a very large horse hypodermic, bought at the Feed & Seed, with the sticky end blunted. The other is a cook's "flavor injector" for injecting meat & poultry. Those also come with a pointy end which should be blunted. Not just for safety, but to be able get the tube right down to the bottom of the reservoir.
GWRdriver
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Emfinger
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Re: hydrostatic oil

Post by Emfinger »

A displacement lubricator should not form an emulsion.
Howard Gorin
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Re: hydrostatic oil

Post by Howard Gorin »

I supply two different steam cylinder oils.
Compounded oil, best for mechanical lubricators, Compounded oils emulsify. This is a desirable property, but not in a displacement lubricator.
Compounded oils will emulsify in a displacement lubricator.
I also supply a non compounded cylinder oil, this will not mix or emulsify in a displacement lubricator.
Non compounded oils work better in condensing systems since the oil easily separates from the water and is then not likely to reenter the boiler with the feed water.
Emfinger
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Re: hydrostatic oil

Post by Emfinger »

That is what I have wanted to hear...how can I get some of your non-compounded oil?
Steve Goodbody
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Re: hydrostatic oil

Post by Steve Goodbody »

Hi Tom,

You may have already considered this, but I believe that it's important that only water enters the oil displacement tank. If the steam hasn't fully condensed by the time it gets to that tank then I believe you will have an emulsion problem.

Hence you may want to take a look at your steam supply run to the tank and ensure the condenser is sufficiently long and/or isn't being heated by something and/or isn't covered with gunk which is acting as an insulator.

I read recently of someone with this exact problem. His loco had an axle-driven water pump and so he ran the lubricator's steam supply pipe through a simple heat-exchanger installed between the water pump outlet and the boiler check valve. Hence the boiler feedwater supply cools and condenses the lubricator steam supply and the lubricator supply warms the boiler feedwater.

Best regards
Steve Goodbody
Emfinger
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Re: hydrostatic oil

Post by Emfinger »

Steve Goodbody wrote: Thu Jul 02, 2020 12:56 pm Hi Tom,

You may have already considered this, but I believe that it's important that only water enters the oil displacement tank. If the steam hasn't fully condensed by the time it gets to that tank then I believe you will have an emulsion problem.

Hence you may want to take a look at your steam supply run to the tank and ensure the condenser is sufficiently long and/or isn't being heated by something and/or isn't covered with gunk which is acting as an insulator.

I read recently of someone with this exact problem. His loco had an axle-driven water pump and so he ran the lubricator's steam supply pipe through a simple heat-exchanger installed between the water pump outlet and the boiler check valve. Hence the boiler feedwater supply cools and condenses the lubricator steam supply and the lubricator supply warms the boiler feedwater.

Best regards
Steve Goodbody
Sorry I don't understand what you are saying !
Steve Goodbody
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Re: hydrostatic oil

Post by Steve Goodbody »

Hi Tom, sorry if my prior post wasn't clear, hopefully the following will help explain. However this potential problem may not apply to your situation.

In summary, it's important that steam (ie, vapor) doesn't enter the oil tank, including when the tank is first re-pressurized after draining and filling. The steam must be condensed into liquid water before it reaches the tank. If steam enters the tank, even briefly, it will tend to bubble and froth the oil in much the same way that a milk-frothing tube froths milk for a cappuccino.

Hence the steam supply pipe should be both long and routed through a cool area to ensure that the steam is condensed into water. Non-horizontal condensing coils located in a cool location are a very good idea, as these will both ensure the steam is condensed and will retain water in the low-points thereby preventing steam from entering the tank when re-pressurized. Hopefully the below sketch helps:
Oil Displacement Lubricator Sketch.jpg
As mentioned in my prior post, I recently read of one person who was having exactly this problem - oil frothing caused by uncondensed steam entering the oil tank. His solution was to route the steam supply pipe through a simple heat exchanger, the other side of the heat exchanger was cooled by the water supply from the axle pump to the boiler.

Lastly, below is a picture showing the hydrostatic lubricator steam supply cooling coils from a full size locomotive - a GWR 28xx in the UK. The coils are mounted immediately under the cab roof - a cool location - and are mounted on a slope to trap water at the low points.
GWR Lubricator Condensor Coil.jpg
GWR Lubricator Condensor Coil.jpg (15.79 KiB) Viewed 6927 times
Best regards
Steve
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