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Hydraulic operated elevator help

drom68

Cast Iron
Joined
Jan 13, 2013
Location
VA, USA
See attached photo, very interesting set up for an elevator that is operated by a hydraulic cylinder.

The hydraulic system, pump, motor and valves are on the second floor due to the building being in a flood zone. Flood happened once back in 1972 so they moved the system upstairs.

Elevator was installed when building was built back in mid-1950's or earlier.

Cylinder ram is at least three stories high, that is how many floors the building has. Ram is one piece, see photo's.

The cylinder is leaking which causes the elevator to creep down when on the first floor in its normal position. The fluid drains into a catch pan with a hose to a bucket.

The cylinder looks to be ok except for the end as you can see in the photo there is fluid at the top and running down. That was from one use while I was there for the demonstration.

While repairing it is beyond my capabilities, I would like to obtain information to pass on to the owner.

** The elevator is only used for moving furniture, no personnel at any time. **

- When does this become a truly unsafe system. The only time it leaks is at the bottom when the elevator is at the first floor.

- Is this a replacement of the top seal only or is it also a symptom of internal leaking at the piston seals.

- Is there an "alternative" fix for the leaking at the top of the ram. See pics, you can see where there are wear marks.

- Any idea of what the cost for that cylinder at three stories high. Not worried about the removal and installation, owner can set that part up. Just worried about the cylinder repair.



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Seeing as know one has responded and I am not an expert on hydraulics, I will posit you this.
There a gent that has you tube channel Adam Booth (ABom) he has several videos of him rebuilding very large pistons. I would try and reach out him for an unofficial pro opinion. If you come up dry hit me back and I'll ask my friend who used to rebuild hydro cylinders for CAT.
 
Advise the owner to call the company that made the elevator to come out and look at it. If they are not still in business, they probably got swallowed up in a merger. Big boys now are Thyssen-Krupp and Otis. Shindler, Mowbry and a few others are still around.
 
I do have a lot of experience,and I can see a coating of oil on the ram.....so you do have a considerable leak....which you know......Is it dangerous.....no,provided non one is in the pit underneath......can it fail suddenly......possibly,if wear on the seals gets bad enough......it is far more likely to run out of oil and fail to lift...........Do you have a drawing of the cylinder........because some cylinders can have packings replaced without withdrawing the ram.......but not yours ,far as I can see.......I suspect you will have to lift the ram out of the cylinder.....a very costly job...........As the ram is 1950s,the packings will likely not be polyurethane ,which does fail completely,but things like graphited asbestos ,or leather....which just wear out.
 
I do not recognize the cylinder. The plunger looks like it is in good shape. You must be shutting down the hydraulic pump when the elevator is not in use otherwise the car would re-level. The packing is replaceable. Any elevator service company should be able to do the job. It involves supporting the car, then disconnecting the plunger, removing tge cylinder head and packing, replacing the packing and reinstalling the head, then reattaching the plunger to the car. This is not a job you want to tackle yourself. Let a professional do it.
 
I do have a lot of experience,and I can see a coating of oil on the ram.....so you do have a considerable leak....which you know......Is it dangerous.....no,provided non one is in the pit underneath......can it fail suddenly......possibly,if wear on the seals gets bad enough......it is far more likely to run out of oil and fail to lift...........Do you have a drawing of the cylinder........because some cylinders can have packings replaced without withdrawing the ram.......but not yours ,far as I can see.......I suspect you will have to lift the ram out of the cylinder.....a very costly job...........As the ram is 1950s,the packings will likely not be polyurethane ,which does fail completely,but things like graphited asbestos ,or leather....which just wear out.

It is interesting on the old type packings and good to hear that they don't fail like newer types. That was a big concern for obvious reasons. Thanks.

I do not recognize the cylinder. The plunger looks like it is in good shape. You must be shutting down the hydraulic pump when the elevator is not in use otherwise the car would re-level. The packing is replaceable. Any elevator service company should be able to do the job. It involves supporting the car, then disconnecting the plunger, removing tge cylinder head and packing, replacing the packing and reinstalling the head, then reattaching the plunger to the car. This is not a job you want to tackle yourself. Let a professional do it.


Thanks for the info. Yes the elevator is shut down when not in use as the pump motor burnt out in the past to constant re-leveling, good catch on that. I have no interest on the job as it is beyond my scope. But I did want to provide some info the owner, so I appreciate the feedback.

I am not interested in the job, but want to follow up with the owner and provide as much info as possible.
 
The packing used in hydraulic elevators is designed to leave an oil film on the plunger. That avoids chatter at low speeds.
 
I used to have one of those in a building I rented a shop in. It was from the 1920s, at the newest. And it leaked into the pit a bit all the time. It ran on water, not fancy hydraulic fluid. But that was in the 80s, and I would guess its long gone, as it would never pass current safety tests for elevators. I cant imagine any city would accept the idea that people never use it- people have this habit of doing what they feel like.
My guess is no real elevator company will work on one of these.
 
A local county courthouse has such an elevator, and it was leaking. They got some elevator company to come out and they were going to tear in to it....here's that story. Sounds like the same problem...

 
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Same as a tip cylinder on a tipping body trailer, they’re triple, get a specialist to deal with it, there are blanked oil galleries in there and all sorts, not a diy project as the welds may need turning out on a long lathe, plus re welding
Mark
 
I must learn to read the bloody date, old I suppose, once you start loosing your dentures it’s time to book a plot
Mark
 
usual way these things go is the OP gets a hydraulic lift service to look at it,and in a strange twist of fate,the Lifts Inspector comes by the next day and issues an "Improvement Notice"...from this point on the lift has to be professionally fixed by a licensed repairer......cant be removed or forgotten about because its in a Fire Plan.........and a mere $50k for the job.
 








 
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