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Mop sink, 3-bay sink, only one floor drain - help?

8K views 9 replies 5 participants last post by  Ghostmaker 
#1 ·
I know this is more of a professional question, but I hoped someone here could help. I have a mop sink, a 3-compartment commercial sink, but only one floor drain available. How on earth should that be connected in a way that passes inspection (i.e. the sink needs an air gap, the 3-compartment sink can't drain into the mop sink or anything funky like that, etc)?

Thanks!
 
#2 ·
Fill us in a bit more. Where does the slop sink drain? Where does the 3 compartment sink drain? The floor drain is probably 3", so it will handle what you throw at it. Why does the sink need an air gap? It may need a Studor valve, or air admittance valve if it is not properly vented. Why would the 3 compartment sink drain into the slop sink? Is it above the sink?
 
#3 ·
I believe the floor drain is 4" diameter. It is under the floor (concrete), but it is an integral trap-style floor drain. Right now, neither sinks are connected. The 3-compartment sink needs an air gap per health code requirements. Right now, the drain is in a small janitorial closet where the mop sink will be mounted. The 3-compartment sink will be mounted on the other side of the closet along the shared rear wall of the closet. Let me try some ASCII art:

Code:
__________
| X | OOO
| O |
The lines are walls. The X represents the floor drain. The Os represent sink bays (obviously, the three Os are the 3-compartment sink while the single O is the mop sink). Neither sink is connected to anything. There will be a pipe going from the 3-compartment sink through the wall of the janitorial closet to reach the floor drain.

My statement about having the 3-compartment sink drain into the mop sink was because that was literally what one of the contractors had suggested - mount the mop sink directly to the floor drain and then have the 3-compartment sink drain into it via an extension - voila! Air gap! :vs_awed: As such, I'm trying to figure out how it SHOULD be done. Shouldn't the mop sink be connected directly to the floor drain? If yes, then how do I have a connection for the sink? If the mop sink is simply mounted on a platform above the floor drain and the 3-compartment sink also has an extension to drain into the floor drain, how do I prevent the drain from overflowing in the event of heavy use?

Let me know if this makes any sense . . .
 
#4 ·
The mop sink will direct connect to the drain system as any other sink would.
The 3 comp sink needs to indirect waste to the floor sink (not a floor drain) with an air gap as you mentioned.
Sometimes you have to open a wall or floor to be code compliant....... Can't cut cornors in a commercial kitchen.

BTW, health dept. will want hand sinks too
 
#6 ·
My wife has a commercial kitchen for her catering business. The 3 compartment sink and the hand sink drain to a floor drain. No traps, the floor drain provides the trap. Each sink has a pipe the runs to the floor drain. The pipes end right above the drain and that provides the air gap.
 
#9 ·
I doubt a floor drain will pass for the 3 comp. sink receptor- I would need a floor sink.

The mop sink can sit on the floor drain trap, but the floor drain body should be removed and the mop sink directly connected to the trap. I assume you have a floor mounted mop sink. If its a wall mount then the trap needs to be above the floor.

Edit: do you need a grease trap?
 
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