Auto drain opinions

Discussion in 'Irrigation' started by DanaMac, Nov 22, 2002.

  1. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,214

    Since we brought it up in another thread, I though i'd elaborate on it.

    I hate auto drains. Despise them. I have repaired many systems for freeze damage that have auto drains. You can not visually see them draining. Blowing out the system ensures there is no water left inside the pipes.

    Auto drains also waste water. With our water shortage in Colorado this year, everydrop is crucial.

    Everytime the pipes drain, they need to be filled back up. So as the water rushes to the end of the line and slams into the last fitting, there is stress put on the fittings. I Have seen many systems with drains that have a lot of water hammmer due to this. There is no resistence on the water as it is rushing 200' to the end of the line.

    I have seen systems that because so much water is rushing through the pipes with no resistence, that the PVB will "chatter" and dump water. That means there is not enough water or pressure to seat the bonnet and poppet together so water dumps out. But then it seats once the lines are filled up. This happens with every zone. It also makes a lot of noise.

    I was once called to a repair that had a leak in a zone. System was at least 20-30 years old. Dug to find the pipe and found it in a trench with 3 other PVC pipes. Of course it was the bottom pipe that was broken. And it was 1 1/2" PVC. And the PVC shattered 60' in length. If you've never seen a PVC freeze break it would amaze you the first time. PVC will shatter. Normally it will stop at a glue joint. This one didn't and and went throung 3 of them. I had to dig up 60" to replace. The system had auto drains and it didn't open up that year.
  2. Ground Master

    Ground Master LawnSite Senior Member
    Messages: 505

    I agree with you on them dam auto drains..........they are a waste.

    Discovered a bad auto drain placed within 2' of a foundation this year. It had been leaking for years - with the system pressurized and not pressurized......home would have water in basement several times throughout the year, but not all the time. Turned out the mainline ran around the house within a foot or so.......and the culpret was that dam auto drain. The ladies husband had put in system many years ago........
  3. Arnold

    Arnold LawnSite Member
    from Wyoming
    Messages: 194

    Never use them but I know I would loose sleep with them in my system during the winter. I believe in blowing the lines out. And every drop of water does count during a drought, I will go along with that.
  4. HBFOXJr

    HBFOXJr LawnSite Bronze Member
    Messages: 1,712

    an irrigation dinosauer or should be. Get real. for what it would cost to install to grade so it will gravity drain, a system can be winterized with a compressor for years. :blob2:
  5. gusbuster

    gusbuster LawnSite Bronze Member
    Messages: 1,928

    One of the first things I did was rip\ cut out the auto drains that were installed on my father's apartment complex in Nevada. They were required by local code when installed by the contractor. Matter of fact, had to change a lot of things. Here, in the bay area, in 30 years in this business I've never seen one or knew they existed until my father's system.

  6. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,214

    Gus - why would they be installed in Nevada or California? You don't get much of a frost line there do ya?

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