My first manifold...advice please.

Discussion in 'Irrigation' started by j_nolesfan, Apr 26, 2007.

  1. j_nolesfan

    j_nolesfan LawnSite Member
    Messages: 81

    Ok guys, this is my first DIY sprinkler system. I've posted a couple of other threads during my project. You guys saved me from the mistake of getting the important parts from Home Depot. :clapping: I'm at the point where I want to connect the first zone to the manifold and I want to think this thing through before I start gluing pipe together. I bought two RainBird prefab manifolds that come with the valves. I have a two valve and a three valve. I have a 1.25" PVC pipe that ends in a ball valve coming out of my well tank that runs parallel to the side of my house. It's about a foot away from the wall and about 8" above the ground. I want to run from the ball valve to the manifold and run straight from the manfold out to the field. However, I'd like to merge all of the pipes in the same trench at some point. The pipes exiting the manifold will all be 1.5". I will only be using 4 of the 5 zones to start (hopefully ever). Now, I'm in northern Florida where it can get below freezing about 10 total days a year so keeping this part from getting too cold is a consideration. Since this is my first manifold installation, I'm totally wide open to suggestion. I would love to hear advice that borrows on your experience.

    Should I use two 45's to drop the pipe down from the tank exit to the manifold instead of two 90's? I ask for pressure drop reasons if it matters. Next, should I put the valves below ground level? If so, should I try to bury them so that the top of the box is level or near level with the ground? I'm looking for pros and cons. I'm thinking of taking the exit of three of the valves out with a 45 degree and fanning them all over until they run the same line (in the same trench). The other option would be to dig a wide trench for 10'-12' until they make a 90 degree turn in opposite directions (two toward the front yard and two toward the back yard). This would cross the trench in the picture. A third option would be to run them straight out like the yellow lines show and 90 them into the trench in the picture. Here's a pic of my setup.
    Thanks again,
  2. j_nolesfan

    j_nolesfan LawnSite Member
    Messages: 81

    Wow, 51 views and nary a reply? Was it something I said? Or didn't say?
  3. Dirty Water

    Dirty Water LawnSite Fanatic
    Messages: 6,794

    Elbow into ground, set valve box so lid is flush with soil level.

    How much you want to dig is the only determing factor as to how to route the pipe out of the valves.
  4. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Messages: 6,200

    dude make your own manifold...and cut back that box...

    WAYYYYYYY to big....get a 6 standard
  5. Remote Pigtails

    Remote Pigtails LawnSite Senior Member
    Messages: 581

    J Let me tell you a story. This was shown at the beginning of 2001 A Space Odyssey. At the dawn of man a giant slab of concrete came to earth and give irrigator monkeys special knowledge. With this special knowledge we learned to use sticks and bang the ground and kill animals which made us strong. Then we went to the watering hole of irrigation knowledge where the DIY monkeys were making a mess of things. We whopped the DIY monkeys upside the head and chased them away. To give this knowledge back we need something in return. Can you impart some wisdom among us? Do you have some funny jokes? Make us irrigator monkeys feel that we are being rewarded for our knowledge.
  6. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,226

    That was great piggie!!!!!!
  7. j_nolesfan

    j_nolesfan LawnSite Member
    Messages: 81

    Well Remote Pigtails, I can say that the name "Remote Pigtails" brings some bizarre fetish pornography to mind. Is that funny? :laugh:

    Monkeys ought not to play with pipes that aren't theirs.

    There once was a monkey from Nantucket...well, you get the picture. (ba-dum bum).

    I'm here all week, please try the fish. Be sure to tip your waiter or waitress.

    I'm not sure exactly what a 6 standard looks like.
    As for the size of the box... and the manifolds, they came as a kit which saved me about $100. The box is a four on the side you see and/or a three on the back side of it. However, to get the manifold in the box as it is layed out, I can't fit the 5th valve on it without cutting the box.

    The kit came with a Rainbird ESP4M outdoor clock, rain sensor, and pump start relay as well as what you see in the picture. I'm still coming out cheaper than if I bought all of the parts separately AND built my own manifold. The only other way I could imagine using this box with 5 valves and building my own manfold would be to alternate the T's where one T went out one side of the box and the next went out the other side. I don't think I could get the configuration any tighter (more compact) than it already is though.

    Anyone know the rules of thumb on pipe length and flow as related to water hammer? I would think that short runs (under 5', etc) wouldn't be very susceptible to water hammer. I ask because the manifold will be handling about 30 GPM in some situations and I plan to run 1.25" pipe to the manifold from the tank. It's probably not an issue but I just want to cover all my bases.
  8. j_nolesfan

    j_nolesfan LawnSite Member
    Messages: 81

    P.S.> I gots nanners. How 'bout some nanner puddin'?
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,750

    If you're running 30 gpm, your valves may be 'hammering' all on their own. For the money, you'll live with it. Tables for pipe friction pressure losses are all over the internet. Find a table, and run the numbers yourself, since that is your responsibility, and no one else's (unless you're paying them for it)

    As for manifolds, they can always be more compact
  10. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,226

    Boots, please stop showing that photo, I cringe and get sick every time I see it :nono:

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