quick question... would a HYDRAULIC piston elevator get damaged if a few people jumped on it during it's trip down. i know that some people in my building often jump as it's going down... would this throw off the system... or spew out oil from the cylinder (leaving air in its place? can this be detected?

my other question is... would an oil leak test determine if air got stuck in a hydraulic cylinder?

-- Jala (menzz@hotmail.com), August 25, 2004

Answers

No, you won't damage the hydraulic piston, but you might trip the overspeed valve. When that happens, you had better hope the local elevator tech is close by, to rescue those knuckleheads.

We love those kind of billable calls.

Most hydraulic systems will bleed out any air in the system just from normal running, provided the oil level is sufficient.

-- Jim Hagerty (themadhag@cox.net), August 25, 2004.

If you had a direct acting hydraulic lift and a few people were juping up and down then you might get the rupture valve to activate. If you had a indirect acting lift(with ropes) then in addition you could also get the overspeed device(if fitted) activated and possibly the safety gear activated as well.

-- Harry (harry@bhua.co.uk), August 27, 2004.

Anything is possible...that being said although it is very unlikely they could damage your elevators piston, if they threw it out of plum enough it could foul the packing and scratch the piston but more likely they'd toss a shoe or roller, clip a door lock on the way by or something...elevators aren't cheap, make em take the stairs

-- (picklesniffer77@yahoo.com), September 19, 2004.

an "oil leak test" as you put it isn't to detect air in the system. It is to determine if there are any leakage points in the system, if you relief valve pressure setting is correct and hasn't changed, and if your "low oil protection" device is operating properly. most of your hydraulic pistons have air bleeds on them to remove the air.

if youve got people jumping in your elevator, you need to have them removed and banned from your building because its eventually going to cost YOU money, loose rails, loose guide shoes, loose cab fasteners, etc, the car will be clipping door locks, and hopefully not wiping out all the vanes and switches. when the mechanic shows up, you'll likely be billed if he see's the damage. i don't like these kinds of calls, they are unnecessary and a damn nuisance, so you know if i show up, i'm gonna be pissed.

-- (kickyoass4fun@aol.com), September 20, 2004.