My initial question was whether they are allowed in a kitchen floor, but I guess the real issue is that they probably don't count for any of the required kitchen outlets if they are in the floor, but I think you can have non-required ones there.
I can't even begin to think that anyone would want this in a commercial kitchen. For starters, water will be spilled on the floor, even if they don't use a washdown or wet mop to clean the floor. Secondly, a water-resistant cover will not do any good whatsoever, once you plug something into one half of the receptacle. Finally, you are looking at a serious trip hazard. Allowed? Perhaps. Good idea? No. :happysad:
I have never used them, but I have seen docs for floor receptacle boxes designed to be used in wet locations. In addition to a waterproof cover, I also believe they were designed so water could drain out of them if the cover didn't do it's job. All brass and very expensive.
I cringe when I see any floor receptacle, or any receptacle mounted face up. It's just a personal thing.
I did some repair work at a house that had a small indoor pool with ceramic tile all around it. There were two floor receptacle boxes in the floor which was wet when I was there. It gave me the creeps just walking on the floor.