Poly Advice for a Non-poly user

Discussion in 'Professional Discussions' started by Hayduke, Jul 23, 2019.

  1. Hayduke

    Hayduke LawnSite Member
    from Oregon
    Messages: 204

    Poly pipe is almost never used in my locale. Not sure why, but could be the smaller properties are not suitable to a pipe puller, frost depth is like 1 inch, rocky soils, steep hillside properties etc.
    I do use it for certain jobs but my experience is limited. So I am looking for advise on a job we recently used poly that is causing me a few headaches.
    We recently installed irrigation for a streamside rehabilitation project. I love this work, it's partially federally funded (thank you tax dollars going back into my pocket!)
    This project used about 30,000 feet of regular 5/8 dripline fed by a couple thousand feet of 3/4" and 1" poly mains fed from a creek.
    Everything is above ground installed on the surface, as it is intended to be a three year system to get the native replantings going, then removed.
    I chose poly as the mains because it is flexible to go over varied terrain and stronger than drip tube, because there is a lot of maintenance with line trimmers and blade trimmers.
    I used Spear's insert barbed fittings for all connections with Oetiker clamps. I got a call six weeks after installation that a few poly mains had blown out of their fittings. What I found was that whereever the fittings had been sitting on the ground in full sun, they had heated up so much that the tubing was loose and the poly could easily be rotated and pulled off by hand. A few had blown out.
    So on my dime we went through the entire system and added an additional worm gear hose clamp to every barbed fitting connection.
    In retrospect, I could have easily just buried every fitting with some dirt to block the sun and it probably would have been fine. But I'm not sure, because the rest of the thousands of feet of poly sits there in the full sun; the temperature of the water when it first comes out is scalding probably 150 degrees. So this hot water may also be leading to expansion of the tubing around the fittings. Max pressure in this system is about 48 psi. Any thoughts are welcome.
  2. Andrew H

    Andrew H LawnSite Silver Member
    Messages: 2,883

    Worm gear clamps as in automotive clamps? Gee that must be fun.

    Use pinch clamps and do at least one clamp for every connection. So if it’s a tee, it would get three or even six
    Butt would get two or four.
    Same with plug, elbows. Etc.
    Auto clamps are slow, pinch clamps are not.
  3. magna111

    magna111 LawnSite Senior Member
    from NJ
    Messages: 501

    I imagine they’re quicker than pulling apart all the fitting to add additional crimp clamps.
    agm likes this.
  4. Andrew H

    Andrew H LawnSite Silver Member
    Messages: 2,883

    He said they’re blowing apart So they should go on quickly. if he does it in the middle of the day, they’ll come off quickly, or he can bring a little map with him.
  5. OP

    Hayduke LawnSite Member
    from Oregon
    Messages: 204

    I did use pinch clamps originally aka Oetiker clamps. They were tight when installed and the ones in the shade are still as tight as the day they were installed. Only two of the 50 or so fittings had actually blown apart, but as insurance to avoid additional call backs I installed worm gear (yes automotive) clamps to all the remaining fittings. So I thought maybe I should have done two pinch clamps per connection, so a tee would get 6, a coupler 4 etc. But I am really not sure this would have helped for the fittings that were in full sun all day. They became so loose after getting hot...
  6. greenmonster304

    greenmonster304 LawnSite Platinum Member
    Messages: 4,222

    3 clamps on mains. I have done a few jobs like this for coastal re vegetation with polyon top of the ground. I have never seen the poly come off the fitting on its own even with one clamp, maybe leak a little. I mean no disrespect, are you sure you have the poly all the way on the fitting and the clamp midway on the barbs?
  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 52,649

    Since poly pipe is not rated for hot water, you are outside of its operating parameters. Is there any 24/7 static pressure in your poly?
    benhargreaves likes this.
  8. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Messages: 6,431

    Like GM said on our mains we do 3 clamps per barbed fitting. So on a T it would be 9 clamps.. Prob overkill..

    After about 15 years I ran into the guy who taught me how to put in systems, service sell ect. He reverted back to 2 clamps on main lines and it blew my mind. I mean dude.. This dude was particular about his sprinklers. To me it was like hearing the world was not round.

    Anyhow Oetiker sells a special clamping too. I use it and no complaints.

    My gut is telling me the heat has something to play with this. I'm not sure but I kind of remember a water temperature that used to posted on some poly pipe.78' Comes to mind.. So if its getting 150' well..

    Poly pipe or die.
    hort101 likes this.
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 52,649

    One aid for poly connections that come loose is the Lox-On strap clamp made by Ideal. They apply more clamping force than any worm-gear clamp, let alone the usual crimp clamp.

  10. OP

    Hayduke LawnSite Member
    from Oregon
    Messages: 204

    No doubt the poly was inserted fully and each pinch clamp tightened down fully with the appropriate tool.
    This is a not static pressure installation; its fed by a gas powered pump out of a creek that gets turned on manually.
    I am thinking it was the hot water. I did some quick research and saw that the common poly itself is rated to 140 degrees Fahrenheit. I have no idea how hot the water gets in the beginning when its running through poly pipe that's been sitting in full sun on a 95 degree day, but I imagine its close to 140 or more. Some of the barbed fittings were actually distorted from the heat.
    Which means I'd have to partially bury the pipe to avoid the situation, which negates the point of this being a temporary system meant to be removed in three years.....

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