SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Thanks everyone for the suggestion!
I went with a 9 zone design.

I can't advise for Ontario backflow requirements, but as long as it can be located higher than the highest sprinkler or pipe downstream, a PVB will be absolute protection for your water supply from a normal sprinkler system's backflow. I would favor a Wilkins 720, as having more reliability.

I'm not experienced enough to comment on the head placement. But you might want to add in semicircles which will show coverage. Look at other posts here for examples.

If you use the PVB with unions take it inside. Don't know if you blow out the PVB but you must blow out the lines to winterize.

Quoted from "Wet_Boots"

Inline dual check valves are not for sprinkler system backflow protection...

Boots is absolutely correct... but brisk, I want to explain something that for the longest time confused me.

There is a backflow preventer know as a DCVA (I think that stands for Duel Check Valve backflow Assymbly). At its core, a DC and a DCVA both use a pair of check valves to prevent water from flowing backwards. But a DCVA uses check valves rated for backflow prevention AND additional assymblies that allows the check valves to be tested independantly of one another so that the device can be verified that it is working correctly.

So you can think of it like this... you use a DC when you would LIKE the water to not flow backwards. You use a DCVA when you NEED the water to not flow backwards.

However, there is another thing to consider when it comes to DCVA. The offer the least protection of all the basic types of industry standard backflow prevention. The reason is that the check valves can easily become fouled and quit working. Even more, if there is enough 'stuff' in the water to allow one valve to become fouled, there is a good probability that the second one will get fouled at the same time. When that happens, you go from redundant backflow protection (two valves) to no protection. As such, some people (and some municipalities) do not believe that DCVAs are appropriate protection from an irrigation system.

So while you might want to use a DCVA (after all, they allow the ability of the backflow preventer to be installed underground or indoors), you might not want to or you might not be allowed to (by local building codes) use them.

Quoted from "wsommariva"

PVBs are expensive and I would not leave it in the garage unless it never freezes in there.

As far as head placement my design on paper didn't relate well to reality. And once I finally settled on a plan, I needed to make a couple adjustments once all my heads were in. But now it's great.

Thanks, I don't have other place to put the PVB, garage is the best place for me. Will it be ok I blow out the water from PVB every fall? Still no good?

Also, my head placement looks good (at least on paper?)

thanks

PVBs are expensive and I would not leave it in the garage unless it never freezes in there.

As far as head placement my design on paper didn't relate well to reality. And once I finally settled on a plan, I needed to make a couple adjustments once all my heads were in. But now it's great.

Let Wetboots answer the backflow preventer question. He's the expert. Also local code should be checked. In my case I bought a Febco PVB and added my own pvc unions. And it had to be at least 12 inches higher that the highest head. But the one in the link does the same thing. Also if you put it in the garage be aware that it may "spit" occasionally.

Quoted from "wsommariva"

Don't have to use funny pipe but it makes an easier install. Toro also says that it cushions the heads in high use areas.

As far as the flower beds, if they are mulched any extra water won't cause erosion.

PVB is a good backflow preventer, double check valves aren't. IMHO. If you can install a PVB use unions so you can take it in in the winter.

This one?

FEBCO FEU765-100 1 in. PVB Backflow Preventer w/ Union Ball Valve Ends

I am in Toronto, so I'll have to winterize the system every fall.... and I plan to install the backflow preventer in garage, so still good to use w/ Union ball valve ends or the regular one?

Any feedback/comments on the head placement or selections?

thanks

Quoted from "Wet_Boots"

Inline dual check valves are not for sprinkler system backflow protection. Once you input your location, specific advice can be given.

I am in Toronto.

thanks

Don't have to use funny pipe but it makes an easier install. Toro also says that it cushions the heads in high use areas.

As far as the flower beds, if they are mulched any extra water won't cause erosion.

PVB is a good backflow preventer, double check valves aren't. IMHO. If you can install a PVB use unions so you can take it in in the winter.