Hi Sky,

You have a good grasp of what you need to do for your system. I prefer the first option. Smaller PVC pipe is cheap, wires can be damaged later crossing the lawn for all sorts of reasons, 25 feet is not far to trench three times and in-line pressure regulators are inexpensive. You may want to think about filters for you drip lines as well. Happy installing. Aloha

Hi lehua13,

Yes, I will definitely install a filter. If I go with option-1 (3 valves at the water faucet), taking the design a step further, how about this configuration?

==========
"T" fitting at water faucet
--- one side of "T" to water faucet.
--- other side of "T" > manual shut off valve > backflow preventer > Y filter > manifold with 3 inline valves

Option-1a ------- Output of each valve > 3/4" PVC pipe buried underground > pressure regulator where pipe exits ground > 1/2" poly hose to drip irrigation components.

-or-

Option-1b ------- Output of each valve > pressure regulator > 1/2" PVC pipe buried under the ground > 1/2" poly hose to drip irrigation components.
==========

2. Will one filter be sufficient for 5 zones? (3 zones now but planning for the future)

3. Will the filter be able to withstand house water pressure all the time since it will be before the valves?

4. Would you have a recommendation for a brand and model valve that has slow open/close action to prevent water hammer?

Thanks for your help,
Sky

Hi Sky,

I would go for T at faucet attached at the existing faucet, 2nd T outlet adapter plus a new faucet and third outlet to the backflow preventer/vacuum breaker. The valves are close to the faucet and controller. A 1" diameter pvc three valve manifold after the BFP/VB with unions on each side of the valves boxed flush with the ground. 1" dia. pvc across the grass. Where the pipe exits the ground three 90 degree bends. After bends 1"x3/4" adapters then filters then regulators. Adapter to 1/2" drip poly. JMHO. Aloha

Hi lehua13,

Thanks for the additional input. I think I can work out the rest of the design now.

Sky

Don't quite understand this Rube Goldberg hook-up. Good luck with it. Just wanted to make your aware that if you are using a atmospheric vacuum breaker as a backflow device, which it sounds like you are from your post, that they are not designed be under constant pressure indefinitely. If your making this system automatic with a controller, your not going to want to go outside each time you want to use it to open the water connection to pressurize the system.

Hi homr,

Could you give me your recommendation for how to configure my drip irrigation system using the info I provided so far? I'm a real novice and am open to all suggestions.

Regarding the backflow preventer, it has to be installed by a licensed plumber since that is required by the city I live in. So it will be a good, city approved one and I will make sure that it is rated to be under constant pressure. Off hand I think it will be a reduced pressure unit and due to the high cost will service drip irrigation in both the front and back yards.

Thanks,
Sky

I would start at the web site of a component provider, such as Rainbird.

I am not a shill for this company. I only listed it, as it is the one I used, and am familiar with their products and site, as I use them for my lawn irrigation system, installed by a contractor, and for my garden irrigation system I built myself.

I assume other companies have similar DIY sites, but I have not used them.

Much easier to learn from these sites than from postings from people who may or may not have ever installed an irrigation system.

Here is a link that might be useful: Rainbird

Sky,
There has been no mention of what your static water pressure is. Also, I gather that you are on city water, so knowing what size service line comes into the house from the street and its length are also things we should know. There is pressure loss in all that piping as that water begins to flow and you have to make sure that there is sufficient pressure left to operate the drip zones. How many feet of drip line are each of the zones going to have and how many gallons per minute do you expect to run. You need to know that to figure your friction loses. Drip systems are generally low volume but I have know way of knowing If your running 2GPM or 8GPM or more or less. Using a RPA backflow device is ok, but be aware that they have a rather large pressure loss thru them. Both a 1/2" and 3/4" Febco lose about 12PSI at 3 GPM flow. If your starting out, for example with 40 PSI static, you will subtract your pressure loses thru your incoming and basement piping, the water meter, backflow, any check valves, irrigation valves and connecting piping.Left over from that you will have the pressure available to operate the drip line. I would think you would need a minimum of 20-25 PSI. So that pressure loss thru the RPA loomes large, maybe. AS you can see there is a little more than just hooking up some pipe and valves to setting up even the smallest of systems. Also hooking up to a hose bib which is usually connected to a 1/2" copper line is generally not a good idea, especially if that 1/2" line is long.(pressure loss). I hope I haven't confused you too much but nothing is worse than building a system and then finding out it does'nt work properly because of pressure issues. As the previous poster suggested, go to a manufacturers site and try to read up on some of the things I brought up. Good luck.

Hi tdscpa,

Thanks for your suggestions. I had checked out the rainbird and other websites but I did not see explanations on having the manifold at the water faucet with the lateral lines going 25 feet underground verses having the main line going 25 feet under ground with the manifold in the irrigation area. But see my comments below.

Hi homr,

Thanks for taking the time to key in all that information. Especially explaining the pressure loss problems. But it looks like my whole plan will have to be revised due to what I learned. See my comments below.

REVISED PLAN:
Thanks to all who contributed to this thread. I really appreciate it. I talked to a city tech and he gave me a link to city ordinances which deal with irrigation systems. From what I read, it appears that the backflow preventer (BP) has to be installed in the main line prior to any branching. This means the BP will have to be installed near the front corner of our property where the main line first enters our property. This will require longer runs from the BP to the irrigation areas in the front and back yards. I'll have to check with a licensed plumber with experience in irrigation systems confirm whether the BP has to be installed before any branching.

But it looks like I have even bigger problems if the BP has to be installed at the front corner of our property:

1. If the BP has to be installed at the front corner of our property, the main line will have to go across our concrete driveway and entry sidewalk to get to our front yard. IÂm reluctant to cut our concrete driveway and entry sidewalk to do this.

2. The path from the BP at the front corner to the back yard is all concrete. That side of the house has concrete from the house to the hollow tile perimeter wall.

A DIFFERENT QUESTION:
Any licensed plumbers reading this? Is there a universal code that says all main lines have to be buried in the ground? Or is it "generally" permissible to run a main line above ground? (Like attached to our hollow tile perimeter wall above the concrete sidewalk?)

Assuming I can get the main line from the BP at the front corner to the back yard, I will have to run the line around the house (buried under ground) to get it to the front yard without having to do item-1. (The other side of the house does not have concrete.)

Sorry for the long post. I guess there is no such thing as a simple drip irrigation system if it is to be done right,
Sky

> A DIFFERENT QUESTION:
Any licensed plumbers reading this? Is there a universal code that says all main lines have to be buried in the ground? Or is it "generally" permissible to run a main line above ground? (Like attached to our hollow tile perimeter wall above the concrete sidewalk?) Forgot to mention that we live in a tropical climate where it NEVER gets to freezing temperatures so we never have to deal with winterizing water pipes going to outside water faucets.

Sky

Sky,
Just wondering if maybe you are misinterpreting the requirements for locating the backflow device. It surely has to be after the water meter. ( Is that outside the house or in the basement?) I'm sure they want you to pay for the water. Are they just saying that you must have a backflow device located before it branches off with piping to serve the sprinkler. In our area of the country, we tap into the water supply just after the water meter,(this is usually in the basement) add a shut-off valve, drain,(for winterization) and then exit with the pipe somewhere
thru the foundation or rim joist. It is here, just outside the wall that we add the backflow device. Then, from here you can do what you had initially planned with the filters and valving.I'm not sure I understand why they would require you to tap in before it comes into the house. Maybe it is a requirement in your area??!!!. Maybe you do not have a basement, so that could change things up a bit!. It's a little hard figuring these things out without seeing it. The states that we work in are very much on top of what the proper requirements are for irrigation tie-ins and what I just explained above is very typical.

>>Sky,
Just wondering if maybe you are misinterpreting the requirements for locating the backflow device. It surely has to be after the water meter. ( Is that outside the house or in the basement?)Hi homer,

Here's the paragraph regarding the backflow preventer:

"All installations treating, handling, manufacturing or using liquids, chemicals, or waste products which may be pollutional, dangerous to health or toxic, or having a non-potable auxiliary water supply shall obtain from the board of water supply the requirements for an approval of the backflow prevention assembly to be installed after the water meters and prior to any branches or tees. It shall be the duty of the person or persons having control of such assemblies to obtain from the board of water supply the requirements for approved devices before the preliminary plans, specifications, and drawings are prepared."

I've sent an email to our local Dept of Public Works asking if the high pressure water line out from the backflow preventer to our back yard has to be buried or if it can be above ground. (Since there is no freezing problem in our area.) Their answer will probably determine whether I pursue installing a drip irrigation system or not.

Thanks for all the help!
Sky

Here is a little system that works for me. DIY cheap & simple. Here is the link: http://youtu.be/MNoL13ptJ6Y

Here is a link that might be useful: Simple easy DIY Drip irrigation