Lubricator Question

[JonRiley56]

Hi,

I just picked up a Lunkenheimer Senior displacement oiler in anticipation of completing my project over the winter. I have a couple of questions having looked it over a bit.

My engine has now changed to a TinyPower M 3x4 single. According to the steamboating guide from the UK SBA the feed should be 25% or so of the piston diameter which puts me at 3/4". The guide is also pretty emphatic about limiting restrictions and goes so far as to suggest sizing the valves above the pipe gauge t limit friction loss thru globe valves etc.

The oiler has inlet and outlet sizes under the 3/4" requirement as well as using globe valves on both the entry and exit pathways for the steam. Should I forego using it in favor of someother method that doesnt restrict flow ? I have an entry point on the top of my engine that would allow for a manual oiler.

If I do use this oiler could I split the steam feed in two and only run one of them thru the oiler ? If I do that, will the potential pressure differential berween the two cause a problem ?

I would be grateful for any help.

jon

[Lopez Mike]

Two things come to mind.

A: Are you sure you want to lubricate this engine? Single expansion engines with iron rigs and iron cylinders generally do fairly well with saturated steam and no oil at all. Maybe once in a while when one is running with the throttle nearly closed thus drying out the steam a lot you might get a squeak.

B: The displacement lubricators I have worked with and own are on a side arm of the steam line. The flow to the engine doesn't flow through the lubricator. Just a bit of steam gets trapped in the top of the lubricator, condenses and sinks to the bottom thus displacing a drop of oil out the same hole that the steam came in through.

I could be way wrong about the design of your lubricator but I have seen three inch steam lines with a lubricator made out of 1/2" pipe hanging on the side of the line.

Mike

[Lopez Mike]

On closer reading of your original post (not my strong point!) I get the impression that the full steam flow passes through this lubricator. Even so I suspect that you will not find the restriction is significant.

My comments on lubricating single expansion engines stand.

Mike

[preaton]

Jon,

You have misunderstood the piping arrangement to the lubricator. The steam to the engine does not go through the lubricator. The lubricator is on a side arm.The inlet steam to the lubricator is supposed to arise above (in height) the outlet as this provides the head of pressure that forces the oil through the outlet. If your lubricator is the one I think it is there is a bulb above the oil container. This acts as a condenser for the inlet steam. The water then drips into the oil container, displacing the oil through the outlet. Simple displacement lubricators just have one connection for steam in and oil out. However the fancier ones like the Lukemheimer provide the extra driving force of the hydrostatic head of pressure that the condenser supplies.

Cheers

Paul

[DetroiTug]

Hi Jon,

In this pic you can see how I have my displacement lubricator mounted. It is simply mounted in a tee. There is typically an oil delivery tube that protrudes into the center of the "bullhead" of the tee and center flow of steam to the engine. A lot of old Displacement lubricators have that missing or never had one it seems. Since this pic was taken, there has been a shut off for the whistle pipe on the right added at the boiler and a shut off at the Tee going to the steam gauges.



These must be mounted in a vertical stand of pipe in a straight run, not in an elbow to work properly. Yep, all the do is act as a condenser for some of the steam from the main steam line to the engine. Condensed steam/water displaces oil back in to the line. They look complicated, but they are actually quite simple in operation.

As for whether or not to use hydrostatic or some form of internal engine lubrication, it's just opinion, but I would not run an engine or anything mechanical without some form of continual lubrication, super-heated or saturated. Water is for cooling and making steam, oil is for lubricating. The tug runs on very saturated steam, if the oiler runs out, the engine starts making a scrubbing chirping sound.

1/2" NPT steam line is ample. I'm running essentially two M's off of one 1/2" line. I suggest ball valves, they are natural throttles, a quick glance determines their position, and in an emergency, they are easy and quick to close. Just make sure they are rated for steam i.e. 300WSP. There needs to be one at the boiler and one beyond the oiler as a throttle.

-Ron

[artemis]

STEAM pressure gauges (particularly the old ones we all love) have a expansion diaphram that is assembled using soft solder (which is good up to about 450 F). To keep the steam temperature from "unsoldering" the assembly, allowing working pressure steam to fill the gauge body, and thereby blowing the glass cover over the gauge face into your (or your passenger's) face a "siphon" is inserted between the connection at the gauge and the shutoff valve of the gauge. This siphon is usually shaped like a "U" or an "O" and NOT LAGGED - this allows the steam in the gauge supply line to condense and collect in the bottom of the "U" or "O" and substantially lowers the temperature of the working fluid in the supply to the gauge. Less glass splinters to pick out of your wife's (or your 6 yo son's) face. And I do believe that ASME requires that on all live steam gauge connections.

[DetroiTug]

Ron, Per your behest, these was added months ago to both pressure gauges.

Thanks, Ron

[Lopez Mike]

There is a lot of 'Juju' magic around internal lubrication. There are multiple points of view and experiences. I have run a live steam locomotive at 100 psi for mega hours with no internnal lubrication. Strath Steam engines in Australia run their single expansion engines in generator duty for thousands of hours with no internal lubrication from the very beginning.

That said, there is an old wives tale (engineers tale?) that once you start lubricating the cylinder walls, they will never get that nice black glaze and will need lubrication from then on. I dunno. I have no hard information on this.

My experience, as I said, is restricted to iron rings on iron bores and single expansion engines. The few times I have gotten a squeak from my engines it has been either the first run after a lay up when there has been superficial rust in the bores and the noise soon goes away, or when running at light throttle and full pressure when the steam passing the throttle valve expands and drys out thus reducing the amount of water on the cylinder wall.

Of course, one needs to put a drop or two of oil on the piston and valve rods one in a while to give the packings a bit of help.

If you don't mind the complication and work of keeping a lubricator full and removing the oil from the feed water, then there is no other drawbacks that I can think of. For me, I admire complications in other people's installations. Few power plants have warmed my heart as much as that in the Wayward Belle (thanks for the ride, Wes!), for example. But I wouldn't duplicate it for my own use.

I spent years nursing extremely high output motorcycle engines. Trying to get them to run for even one hour without strewing bits all over the race track. My boat is as basic as I can arrange it. I want to be able to show the neighbor's ten year old girl how to run it and then sit on the bow and pretend to be Popeye.

Mike

[JonRiley56]

Hi Everyone,

Thanks for the replies. Not running with an oiler would be simpler..........of course that would mean I have a nice one for sale..
If someone can give me more detail on how this modle works I would appreciate it. It is the "senior" model that does not have the condensation bulb on it. I am confused as I read the operating insturctions, they seem to leave out the step of turning on the main steam valve.

I am also not clear on how the oil feed is regulated from the needle valve in the bottom of the oil sight glass. I have posted a pic of the oiler and also the instructions.

jon

[preaton]

There is meant to be a condenser pipe and valve from the steam inlet that connects to the vertical pipe. One neat installation I saw had a nice coil of 4 0r 5 turns of copper pipe as the condenser all polished and shiny. This valve is used to isolate the lubricator. The valve at the bottom of the oil sight glass adjusts the oil. Big locomotive practice was 1 drop every 2 minutes !! (You don't need a lot of oil) What you can't see is that inside the oil reservoir there is an internal pipe leading from the oil valve to the top of the reservoir. Oil floats on the condensed water. The oil comes out the second connection.

It is interesting that the instructions say to take the steam off above the throttle valve. This means that if the steam stop valve at the boiler is open and the engine stopped with closed throttle, the lubricator will keep on dripping. I guess the throttle is usually to close to the engine and there is usually no decent run of vertical pipe.

By the way Ron's lubricator is a "Junior" I think and has only one connection to the steam pipe