backflow preventer info needed

nicholas bonham-carter

I have 2 hot water systems in separate bldgs. and have been given notice from the local [omaha ne.] gas & water co. to comply with the need for separation between the boiler and the potable water system.
I know that some of you do not even connect the boiler to the potable side and fill it with a hose at first installation and at subsequent annual inspections.
any suggestions for me to follow?thanks in advance.--nbc

Unknown

Backflow

I just use these on my installs.
A small upstream check-valve prevents nuisance leaking.

Dave

nicholas bonham-carter

backflow preventer info needed

i certainly understand the danger of cross-contamination between boiler and potable water supplies [legionella et al].
however ,if the boiler is not permanently connected to the water supply except during yearly maintainance: then maybe there is no need for a conventional backflow [and it's annual inspection fee!].
maybe just a hose connection with a check/anti-syphon valve in line will do.
thanks for your input--nbc

Jim Erhardt_3

LWCO

If you are not going to have a PRV permanently piped into the system, you would be VERY wise to use a LWCO. Otherwise the Watts 9D or 9-11 should keep the inspector happy;

http://www.watts.com/pdf/ES-9DM3_M2.pdf

http://www.watts.com/pdf/ES-911.pdf

oil-2-4-6-gas

it depends on the size of the equipment --and locality some ,you can use the 9d and the 911(the 1 without the vent? ) others you will need the 009, 007, 919 (these are quite a bit more expensive and must be installed by a plumber qualified,licensed to test backflow preventers ) ask the inspector or find out your local code as to which model is required -- honestly if they say the 9d is ok --thank him and buy him a cup of coffee

Home Depot Employee

The 009's work well. Too many times an inspector forces his hand and make a person install a full blown RPZ like a 009 or 909, only to have it fail shortly after. The big units erode the seats quickly because they were not designed for low flow rates.

tim smith

we are required to use 009 or similar

as they have to be able to be tested for opening pressure, close off pressure etc. If you do any of these you must install a y strainer before it to prevent nuisance fouling. Good luck, Tim

nicholas bonham-carter

backflow insp. fee--ugh!!

if the system [1895 gravity system]is not plumbed in ,and is only filled once in a blue moon with a hose ;surely it needs no backflow and no annual inspection.
i think these things should only be installed where there is an automatic fill valve ,and not on a system which never loses water like this one. i do agree that legionella is a danger which should be protected against ,but no permanent water connection is the ultimate air gap!
its a nuisance and an unneccessary yearly expense to install these things where they are not needed--nbc

Tom Hopkins

Why not use a system feeder? The MF200 is perfect for residential size jobs. See them on www.axiomind.com