sprinkler/irrigation install question

[kingranch]

I'm in process of building a system and want to do it so as to not break any codes pertaining to the Pressure vacuum breaker. My property has a large elevation change and the top of the lawn will need several sprinkler heads that will likely end up 8-10 ft above the grade of the water feed/valves. Code states that the PVB needs to be 12 inches above the highest head. How can I achieve this without a 11ft tall pvc pipe loop for the PVB?

light blue is well/water tap where the sprinkler valves and controller will be

dark blue is planned heads for irrigation to lawn and they sit roughly 8-10 ft uphill

[TxKronik]

sprinkler/irrigation install question

As a state licensed licensed plumbing inspector I’d recommend you Install a double check valve or a RPZ instead of a PVB.

If your area won’t allow double check install the RPZ. Some want a high hazard back flow preventer like a PVB or RPZ. Some allow Double Checks.

PVB aren’t rated for any back pressure RPZ and Double Check are. 10ft elevation equals approximately 5lbs back pressure.

DC can be in a box under ground RPZ must be above ground but not above any heads.

[kingranch]

Thanks for the quick reply just the kind I was looking for.
So of those 2 which one would be the cheaper route? Double chk?

[TxKronik]

sprinkler/irrigation install question

Double check is cheaper. What size line are you installing it on?

[kingranch]

1 1/4 inch but was planning to downsize it to 1 or 3/4 at the valve

[Bruiser]

dont exceed 5' per second pipe size is dependant on flow

[TxKronik]

850 Bronze FNPT 1-in Double-Check Backflow Preventer https://www.lowes.com/pd/FEBCO-1-in-...-Valve/3406170

[TxKronik]

Here is the RPZ

[kingranch]

Ok

On the double chk does that need to be buried in a box or should it be above ground like the PVB typically is and covered w insulation?

Thx for the help

[ramrod]

It can be above ground. Just insulate it.

[TxKronik]

Ok

On the double chk does that need to be buried in a box or should it be above ground like the PVB typically is and covered w insulation?

Thx for the help

Your choice can be in a box below ground like your water meter or above ground and insulated.

[Todd-ty729]

TxKronik looks like he has this covered!

I agree on the Double Check in a valve box in the ground.

RPZ's are more likely to give issues down the road

[topwater blowup]

Great information,

if you are self installing, you can go to the rain bird website, upload your property description map and they will send you a detailed irrigation design for free.

[mattjproc]

Double check will be cheapest/easiest. Just make sure your city/county allows it. Many areas are requiring RPZ for irrigation backflow protection now.

[RedBear78]

TxKronik looks like he has this covered!

I agree on the Double Check in a valve box in the ground.

RPZ's are more likely to give issues down the road

Yea I’m an irrigator but no need in saying things twice he’s got it covered I guess I’ll go back to work and try and earn my keep down here.