Backflow Preventer Question

nycpa

I wanted to install a backflow preventer for my steam boiler feed line.  I was thinking of a Watts 1/2" 9D-M3 Dual Check Valve w/ Intermediate Atmospheric Vent.  What does the following mean:

<strong>Do not use this item for any installation or repair of potable water applications. This product does not comply with the "Safe Drinking Water Act," which requires that products meet low-lead standards in order to be used in systems providing water for human consumption (drinking or cooking). This item is for non-potable (non-human consumption) water applications only</strong>

Can lead ever get back into my house water?  If so, wouldn't it be better not to have a backflow preventer.  Also, during spring/summer time, if I shut off the water supply to the boiler, will that cause the backflow preventer to start leaking water since there isn't pressure going forward?

Thanks

ChrisJ

Just a homeowner here

But this is the model I used as it's rated for high temperatures. 

http://www.pexsupply.com/Watts-0063191-BBFP-1-2-CxC-Backflow-Preventer



It also has the same warning which I believe is related to lead levels in the product and the standard was recently reduced so just a few months ago, none of these products had the warning.  I interpret this as don't use it to feed a supply which you will drink from like a kitchen sink, so the boiler is fine.

nycpa

one more question

Thanks for the response, i have two more questions:

1) What piping do I connect to the middle drain opening?  I would need to run it 15 feet to get to my laundry basin drain.



2) In the spring/summer time, it i turn off the shut off valve before it, will it cause the water in the valve to leak since there is no consent forward pressure?

ChrisJ

Vent

I didn't connect anything to the vent on mine. I kind of pulled a "titanic" and left it off because I thought it would look bad and the inspector didn't care. I believe, the vent is where water will come out of if the device needs to release pressure so if it could damage anything I would run it down to the floor away from things. On my previous system I had the backflow preventer leak from the vent but very little. Most guys just run a 1/2" pipe from the vent down to the floor.



On mine, I manually feed the boiler via a valve after the backflow preventer. I also have a valve before it but I leave it on. I suspect you will get a leak if you release pressure on the inlet side before you do on the outlet as that's it's job, to prevent things from going backwards.