Watts 9d backflow preventer

cowie_4

Why does the vent on a Watts 911D drip water?? I was told that you could put a plug into it if it was on well water. Is this true??

Thanks,

Jay

Unknown

Don`t plug-it,,,

then you`re just defeating its purpose of being there in the first place.

Just install a small ½" swing check upstream of-it and you should be OK. :-)

EricAune

More than one reason likely

The vent can expel water for more than one reason, check the tech documents on their site for list of reasons.



If it has been in service for a while the most common reason would be the spring or gasket has something on the face and is not making a positive seal. 



Do not plug it, it is telling you something is wrong....fix it.  Not sure what a check valve would do?

Mark Eatherton

Check valve...

installed on the inlet to the backflow preventer will keep the device from seeing any nuisance pressure drops created by high demand fixtures on the potable water system (solenoid controlled devices and flushometers).



Perfectly acceptable. Honestly, I don't know why the manufacturers don't just include on in the assembly in the first place...

ME

Al Letellier_21

dripping 9D

Might be doing what it is supposed to do or it may need rebuilding but as Mark says, don't plug it......make sure you pipe that vent to a safe place or a suitable drain. I have investigated many water damage claims where for the lack of a little extra pipe, a lot of damage could have been prevented. This is a could place to use up some of your PEX scrap pieces, just don't reduce the size of the vent.

Ron Jr._3

Correct me if I'm wrong

but would the check part of the Watts 9D still work if the vent is plugged ?



We stopped using the 9D years ago due to this same nuisance problem . We use the Wilkins double check , ventless backflow preventer . On small residential jobs with a PRV on the feed line , it's the way to go .

Andy_27

check installation

Make sure that the backflow preventer is installed upstream of the PRV. The 9D requires a 12 - 14 psi differential accross it to work correctly (not drip)