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NCDesign (Mechanical) (OP)
9 Sep 08 11:09
I'm not sure if this is the right forum, but this one gets lots of eyes so I'll give it a shot.

I just got surprised on a project with a 55 GPM per elevator sump pump requirement.  This apparently originates from ANSI A17.1 Elevator code.  I have 3 elevators sharing a pump so according to this I would need 165 GPM of sump pump capacity.  This seems extremely excessive to me.  The currently specified pump is rated at 65 GPM and when derated for hydraulic fluid could empty the sump (the sump and main elevator basin can contain the entire amount of hydraulic fluid so overflowing that is not a possiblity) in less than 10 minutes if there was a catastrophic hydraulic fluid event (all three elevators lost all of their hydraulic fluid at the same time). I would think that if all three elevators emptied their hydraulic fluid at the same time you would have greater concerns than whether or not the sump was emptied.  I would think things like is the building still standing would be more important.  

Furthermore it seems the ANSI requirement is geared more towards water build-up in the sump than hydraulic fluid.  I don't have a large enough domestic water pipe in the building to supply 165 gpm of water and a good portion of the roof would have to leak into the elevator shaft to require this flow rate.  On top of this per local code I have to provide exterior storage for whatever this pump pumps so it doesn't get into the sanitary or storm sewer.  If there is a catastrophic water event (something that actually requires 165 GPM of flow) my storage tank will only contain it for about 3-1/2 minutes before it starts overflowing (although it will contain all the hydraulic fluid if it is just a hydraulic event.)  So I am a bit puzzled.  I am also a bit handicapped in that at this point I don't have the referenced elevator code.

I know this has been long winded but, does anyone here have any experience with this?  Any other thoughts or words of wisdom?  Right now I think this is ridiculous.  
 
MintJulep (Mechanical)
9 Sep 08 12:07
No direct experience, but as I see things, you have a few options:

1.  Design a compliant system and be done with it.

2.  Take the info in your post to the building owner and ask him if he wants to pay for your time to discuss the issue with the relevant building inspectors, try to convince them that a non-compliant system would be ok, fully document the results of all such discussions to that everyone's ass is covered and design a non-compliant system.

Note that option 2 involves the risk that the inspector will say "no", in which case you are back to option 1.  
GMcD (Mechanical)
9 Sep 08 16:30
Funny- in my jurisdiction our Elevator Inspection Branch specifically forbids any kind of drain, sump, sump pump or other appurtenance that does not directly relate to the function of the elevator in all elevator pits.  For groundwater control the design here is to "tank" the elevator pit and water proof the heck out of it so no ground water can seep in.  If a sprinkler goes off in a fire event, yeah, the elevator pit will fill with water, but so what?  Roll in a temporary sump pump and suck it out as part of the post fire event clean-up.
NCDesign (Mechanical) (OP)
9 Sep 08 19:18
MintJulep thanks for the input.  Unfortunately the system has already been designed and installed and has been through option 2 which brings me back to option 1.  Apparently this requirement is brand new and the elevator inspectors are just starting (it is a point of emphasis, stealing from this past weekend's college football mess) to enforce it.  If we don't comply there is no certificate of occupancy.

GMcD what is your jurisdiction?  I think they have it right.  I am not really sure what the logic is behind the requirement and it seems to put an unnecessary burden on the owner.  I partially understood when it was directed at hydraulic fluid, because the logic was it was keeping it out of the sanitary or storm sewer.  Being able to drain the pit while the sprinklers go off seems a bit ridiculous to me.  I guess maybe it indicates that they do want to use the elevators in case of a fire.  I need to chase that angle down.  Thanks.
GMcD (Mechanical)
9 Sep 08 19:54
NCDesign:  I'm in Canada, British Columbia, and our elevators fall under the "Safety BC" group and they have their own home-made Codes here.
MintJulep (Mechanical)
9 Sep 08 20:23
If design, approval and construction all happened before the new requirement became effective then certainly there is no basis for withholding the COA.  Right?
NCDesign (Mechanical) (OP)
10 Sep 08 11:42
You are correct MintJulep.  But apparently there is some discrepency as to when the elevator code changed and became enforcable.  I did some further investigating and what I have concluded is I have two departments that are completely seperate (one state, one local) that both have elevator sump pump requirements for different reasons that don't mesh.  I am setting up a meeting with the developer/GC, elevator inspector, building inspector, and the town waste water guru to try and get the elevator inspector and waste water guru to come to some sort of compromise that is possible to install.  
Thanks for the sounding board.  I'll let you know what happens.  As a side note here are a couple of interesting items I found on the subject.

http://www.psdmagazine.com/pdf/May_Jun_05/54_55.pdf
http://www.elevatorinspector.com/sumps.htm

   

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