Vacuum breaker install for sprinkler system

Derstig · Jun 18, 2017

Hi all,

I have been building my own sprinkler system (all in all its front and backyard and a total of 12 zones so its pretty massive). I have been doing all the work myself and as such temporarily i connected everything to my faucet via hose bib. I am using a vacuum breaker there that screws in but I understand this is not the "pro" way of doing this and I need a 1" copper pipe that connects to my water main with a T after the meter and that I need to install those big expensive vacuum breakers that cost $100 each.

I got some quotes from plumbers and I was told around $1500-$2000 including parts for this. I have no proper plumbing experience although I have been laying down so much poly and pvc pipe that I have become handy with the torch. I am thinking of doing the install myself but I dont know if its a good idea.

The amount of money it has to cost me to install 5 zones and over 20 heads as well as buying enough top soil and seeds for a land of 15,000 sq ft was $1500. Now spending just as much for bunch of pipes is a lot although i m sure this takes all day. There is also going to be concrete drilling involved as my house is old and has double side concrete walls which I need to drill through.

Thoughts? If I can pull this off myself, any pointers or should I just not bother with it because it might be catastrophic?

havasu · Jun 18, 2017

If you can shut off the water at the main, before the sprinklers, I see no reason why you couldn't keep going and connect the main. Don't forget to include ball type shut off and isolation valves.

CT-18 · Jun 19, 2017

Depending where you live those back flows need to be tested by a certified tester. You may want to give it a shot, worse case you hire someone to finish what you dont.

Derstig · Jun 19, 2017

I have some follow up questions:

- What is the difference between shutoff and isolation valves? Where would they be placed?
- The plumber that gave me the quote confused me by saying I need a backflow preventer both before and after the shutoff, one inside and one outside. And he said I need one for the backyard and front yard separate. Is this true? Why cant I just put the backflow preventer right after the T after the water meter. Then put the shutoff valve and after that run 2 lines, one for front and one for backyard.

So in other words.

Street -> meter -> T connection splits to house and sprinkler -> backflow preventer -> shutoff for the entire sprinkler lines -> T connection that splits to front and backyard.

- He also told me there are two types of pipes and I need the "L" type which is expensive but for this type of pressure/load, that has to be used.

CT-18 · Jun 20, 2017

Not sure what the difference would be in the valves. I know in the old days they could only use gate valves at the meter not ball valves.

Each area has its codes and regulations about irrigation systems. In my area if the vacuum breaker covers the whole system that is all that is needed.

I would use L copper as it is outside to the elements