Backflow Preventer in Faucets with Sidespray

[daaguirre]

Hi everyone,

I am an entry level plumbing engineer looking for the opinion of a more experienced mechanical / plumbing engineer on the following:

Do kitchen faucets that meet ANSI A112.18.1M have an integral backflow preventer device or do they require an additional backflow preventer device (e.g. an inline vacuum breaker)? I am concerned with contamination of the water supply since the sidespray could potentially end up submerged in the sink.

I am working on a project in which water tempering valves have only been provided for the faucets located in the lavatories but not for the faucets located in the kitchen, service and mop sinks. It seems to me that the faucets in the kitchen sinks, service sinks and mop sinks should also have a tempering valve, since there is risk of scalding in those plumbing fixtures as well. Is this a mistake or is there a reason for the valves to be installed only in the lavatories?

Regards,
Donovan

 

[fel3]

There should be* a backflow preventer between the water main and the building to protect the public water supply from nefarious activities inside the building. So, what happens in Vegas, will stay in Vegas. I have never heard of having a BFP on a faucet, but my expertise is outside the building, not inside.

* I said "should be" instead of "will be" because sometimes the BFP isn't there even when required.

==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[PEDARRIN2]

No additional backflow required for the sink.

The International Plumbing Code requires thermostatic valves listed to ASSE 1070 to be placed at all public hand washing fixtures. Since the function of kitchen sinks, service sinks and/or mop sinks is not hand washing, thermostatic valves are not required. An exception (not per code) are hand washing sinks in commercial kitchens. Though not public, I would recommend putting the valves at this location.

By the way, there is a plumbing engineering forum to ask plumbing specific questions.

 

[daaguirre]

Thanks for the replies,

Upon further reading, I discovered that the faucets that meet ANSI A112.18.1M are already designed to prevent backflow:

[link

http://villageofalsip.org/Cross Connection Hazards brochure.pdf

]Cross Connection Hazard Brochure[/url]

PEDARRIN2, would you mind sharing the address for the plumbing engineering forum. This is the closest I could find to a plumbing engineering forum on eng-tips.com.

Thanks !

 

[PEDARRIN2]

Go to the forums list and it is under "Engineering Forums by Industry"