[Master Brian]

I am needing to install a PBV Backflow for my sprinkler system. I will be tieing into the main water line from inside my basement and going out under the foundation. The house was built in 1915 and basically only has about an 8" thick footing, which is maybe 1-1/2' below grade, at the point where I plan to tie into.

The main supply to the house is 3/4" copper, but I have an area, where I tee'd off the main line with 3/4" pex so I could place all outside hydrants on a shut off valve inside the house.

I have 2 questions:
1) Should I tee off the pex for the irrigation system or off of the main copper line? If I tee off the pex, I would have 1 more shut-off location if anything went wrong....but I question if I'd have more pressure if I tee off the copper, since less bends and such. I have easy access to both lines in the same area.

2) What is the best option for material to use for the supply side of the PBV Valve? PVC seems to be the most commonly used, but I am not real sure I want pressurized PVC inside my basement running underneath the footing. I will likely sleeve whatever I go with.

 

[Master Brian]

Another question I am curious about is, could this be installed inside my basement?

 

[burnt03]

I'm pretty sure that a PBV has to be installed at least 12" higher than any downstream piping. Plus, the way it works is that it exhausts water when there's backsiphonage so if something went wrong, you could have a mess on your hands. So, if you want to keep the backflow in the basement, maybe use a double check valve assembly instead.

 

[Master Brian]

I'm pretty sure that a PBV has to be installed at least 12" higher than any downstream piping. Plus, the way it works is that it exhausts water when there's backsiphonage so if something went wrong, you could have a mess on your hands. So, if you want to keep the backflow in the basement, maybe use a double check valve assembly instead.

I thought I had read somewhere they should be outside, but today I read something about putting them inside, which made me wonder. I think I'll stick with putting it outside. The height wouldn't be a problem, but I don't want to add any water to my basement....

Thanks!