We have a hydraulic elevator (inground) in a building. The building is being re purposed. The 6th floor is not being used any more.

I would appreciate any input of what you have done in the past for adding a stop ring on the piston.

Kept the stop ring in place and cut the top off the piston then welded the top plate back on. Make sure you add some signage stating that the piston is shorter than the cylinder, otherwise you could loose the piston down in the cylinder during a repack in the future, it would not be fun trying to fish it out.

Put a sleeve on piston. Floor to floor length of 5 to 6. May change your pressures. When building decides to change their mind on it, then just remove sleeve.

I would second JustWolf and would recommend adding small nylon set screws to the sleeve so it keeps it from clanking around and also so it won't damage the piston if they ever want to reuse it again. We had had EECO make us a sleeve like that a few years ago for one of their jacks. All we did is land the car removed the head pushed the sleeve down below the head put it back together and it pushed itself to the bottom of the jack and stayed there.

I have never added much more than a 10 inch sleeve or so, but I agree with ABE on a need for securing it. We always used brass set screws, the brass is too soft to damage the piston, yet strong enough to keep the new ring from clanging.

Curiosity here, maybe one of the code gurus can steer me. What if, you used a piston gripper to stop upward movement after code dictated over travel? Maybe have a vane, or cam with a limit switch, that could activate the gripper? Think this would meet code? Remember the piston does have a stop ring to prevent catastrophe, so if all we needed to do was reduce over travel.... Just a weird thought I had.

Silly,
If a pistol gripper was utilized in suck a fashion, the stop ring would still be the final limit in which the piston can travel when electrical or mechanical devises fail.

Solidstate,
When was the unit installed?
Has the unit been modernized?
How old is the jack assembly?
How Is the controller and car station being changed to eliminate the 6th?

If they truly wish to eliminate the 6th floor, the system should be modernized to reflect such a change. If the unit is to be modernized and the jack assembly isn't being replaced, then I agree a sleeve is a great solution to shorten the travel of the piston.

If they don't wish to modernize the unit, why not just disconnect the car and hall calls for the 6th floor at the controller?

Thanks everybody. I spoke with EECO and they will build the sleeve.



JKH
95
no
21 years
removing wires and buttons, moving terminal and finals down


There will be no access(locked service access door) to the current 6th floor.

Code requires a mechanical stop at the top floor. I assume in case of entrapment, and the electrical stops fail to prevent the car from continuing to run. It could be difficult to free the entrapped passengers.