Displacement lubricator questions

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NP317
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Re: Displacement lubricator questions

Post by NP317 »

Chris:
Check your Private Messages.
RussN
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NP317
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Re: Displacement lubricator questions

Post by NP317 »

FKreider wrote:
[snip]
Is this the style that he wrote about in the 1978 Live Steam article? I've been wanting to see a copy of said article for a while now.

"Get Positive Oil Feed with a Hydro-Force Lubricator", William S. Van Brocklin, Jr, Live Steam Magazine, November 1978
Check your private messages.
RussN
Emfinger
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Re: Displacement lubricator questions

Post by Emfinger »

Jack,
I have cleaned out the lubricator, purchased quality steam oil, but I don't know if should leave space when I fill them.
Tom
FKreider
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Re: Displacement lubricator questions

Post by FKreider »

Van Brocklin's Hydro-force lubricator under construction...
116590457_294063755217254_3851559616886060900_n.jpg
-Frank K.
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Chris Hollands
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Re: Displacement lubricator questions

Post by Chris Hollands »

I'm doing the same thing Frank with a slight difference , this will be a horizontally opposed version to suit the challenger with 4 outlets and needle valves built into the body to control flows to each cylinder .
As in the photos each side will have an indicator to show how much oil has been used , also it gives a slight surface area difference so the piston side has a more positive force ( that's the theory ).
OD is 2" and ID is 1 3/4" and 8" long with 5/16 indicators , I may change that to 3/8 to give a slightly more bias to the piston side .
It has a common steam pressure supply from the throttle to operate each section .
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Bill Shields
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Re: Displacement lubricator questions

Post by Bill Shields »

be careful of double o-rings.

if you build up pressure between them you can cause the piston to stick.

in reality (and experience), if one o-ring does not work, then your design criteria for the crush and groove clearances are wrong...and duplicating it in another ring is only going to make it worse.
Too many things going on to bother listing them.
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Chris Hollands
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Re: Displacement lubricator questions

Post by Chris Hollands »

Thanks Bill , that is an easy fix new piston with one oring .
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Bill Shields
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Re: Displacement lubricator questions

Post by Bill Shields »

Or just leave one ring off the existing.piston :mrgreen:
Too many things going on to bother listing them.
Emfinger
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Re: Displacement lubricator questions

Post by Emfinger »

gwrdriver wrote: Thu May 14, 2020 7:32 am In world "garden" gauge live steam (45mm gauge), where I am also an active builder, 99% of locomotives use hydrostatic lubricators, also called displacement lubricators. Most of the commercially produced locomotives (arguably the majority currently on the rails) rely upon a drilled hole in the feed tube to meter oil delivery. Almost invariably they get it right, but every once in a while they don't. Needle valves are the best control method but are rarely used in small scales because it adds product production costs, and a drilled hole works.

Displacement lubricators work because within that tiny orifice a molecular miracle happens . . . steam goes in (to the lubricator reservoir), and oil comes out, at the same time. The steam which makes it into the reservoir condenses and the accumulation of water under the oil in the reservoir "Displaces" (hence displacement lubrication) the oil, pushing it out into the steam supply line where it emulsifies as it travels to the cylinders. The process is helped along by tiny pulses in steam line pressure as the engine runs. As for Gravity, it has very little effect on the process, except that it pulls the water to the bottom of the reservoir, and in 45mm gauge a guideline is to mount the lubricator as near to the cylinders and as far from the fire as possible. For the lubricator to work the body must be cooler than the steam.

The hydraulic forces are tiny so no check valves are used but the oil entry point (to the steam line), which may be a "Tee" directly connected to the steam supply line, or a short dedicated lubricator line, must be beyond (downstream) of the throttle to prevent oil being drawn back into the boiler by a vacuum when the loco is cooled down.

A necessary construction detail is that there must be a starting air space in the reservoir, otherwise in a completely filled reservoir the condensation phase won't start and self-sustain. Typically the air space is provided by counter-drilling or machining a recess the lubricator cap. A very handy detail to include is a water drain in the bottom of the reservoir.

That's the way it works and has since the invention of displacement lubrication.
I don't know how I missed your notes.....I just found them..thank you...you said it well and on the mark.
Thank you very much
Tom
FKreider
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Re: Displacement lubricator questions

Post by FKreider »

Bill Shields wrote: Wed Aug 05, 2020 11:52 am be careful of double o-rings.

if you build up pressure between them you can cause the piston to stick.

in reality (and experience), if one o-ring does not work, then your design criteria for the crush and groove clearances are wrong...and duplicating it in another ring is only going to make it worse.
In my case the double o-ring part shown is the removable end cap - I did not trust the single o-ring to hold all the oil back :mrgreen:

I still have to fabricate the piston and I will be going with a single o-ring.
-Frank K.
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milwiron
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Re: Displacement lubricator questions

Post by milwiron »

Curious if there are any updates running this lubricator. From the post below it looks like it was almost ready to go.
Denny
Chris Hollands wrote: Wed Aug 05, 2020 10:55 am I'm doing the same thing Frank with a slight difference , this will be a horizontally opposed version to suit the challenger with 4 outlets and needle valves built into the body to control flows to each cylinder .
As in the photos each side will have an indicator to show how much oil has been used , also it gives a slight surface area difference so the piston side has a more positive force ( that's the theory ).
OD is 2" and ID is 1 3/4" and 8" long with 5/16 indicators , I may change that to 3/8 to give a slightly more bias to the piston side .
It has a common steam pressure supply from the throttle to operate each section .
"Measure twice, curse once."
Mjordan
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Re: Displacement lubricator questions

Post by Mjordan »

This is the forced displacement oil system my grandfather put on the Huntington. It uses the water pressure from the axle pump to push the piston up. Then it feed to two water glasses to monitor flow to each cylinder. I just finished putting it back to lgether as they glass broke during its first run in 20years at Mid-South Steamers.

Not sure if it helps but I do like the glass to see the oil level/consumption.
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