2" Thin-Wall (Sch 200?) Balloned!

Discussion in 'Irrigation' started by MEXANDME, Mar 10, 2009.

  1. MEXANDME

    MEXANDME LawnSite Senior Member
    Posts: 396

    I had to do a repair on a 2" pressurized irrigation line the other day and it was "balloned" near a tee that I was replacing. A coupling would not fit over the old pipe once I cut it in two! Once I dug back further and cut off more old pipe, the coupling fit. This system is fed by city water but used to be fed by a golf course irrigation system. Could the high pressure from the golf course system have actually caused the pipe to "ballon" at the tee fitting? (I do not know exactly what type the 2" pipe is but it is thinner than SCH40.)
     
  2. AI Inc

    AI Inc LawnSite Fanatic
    Posts: 25,155

    Did it actualy balloon , or did it egg out of round?
     
  3. MEXANDME

    MEXANDME LawnSite Senior Member
    Posts: 396

    No, it was not egg-shaped. That was the first thing I looked at. It was like the pipe was 1/32" or so too wide all the way around.
     
  4. Dripit good

    Dripit good LawnSite Bronze Member
    Posts: 1,081

    Yea. PVC has the ability to balloon quite a bit before it bursts!

    P5210173.jpg

    P5210173.jpg
     
  5. AI Inc

    AI Inc LawnSite Fanatic
    Posts: 25,155

    wow, looks like a friggen tumor.
     
  6. AI Inc

    AI Inc LawnSite Fanatic
    Posts: 25,155

    Drip , was that near a pump, was it heat related?
     
  7. MEX do you know what the allowable constant pressure on CLASS 200 pipe is? Not trying to trip you up but just curious.
     
  8. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    In my best possible Arnold accent - "It's not a tumor".
     
  9. Dripit good

    Dripit good LawnSite Bronze Member
    Posts: 1,081

    Yes sir. This came right out of the pump and 90'ed into the ground. Bad solenoid prevented flow. I'm thinking the water heated up, and with the increasing pressure ballooned (at it's weakest point) before bursting. If the prv didn't also fail, this wouldn't have happened. Changed it out to galvanized and replaced the prv. IMO it's still a ticking time bomb without mercoids.
     
  10. Sprinkus

    Sprinkus LawnSite Silver Member
    Posts: 2,048

    Could be excessive velocity and/or pressure in the line that caused the problem. I've also seen that happen in areas where solvents, like paint thinner, or fuels, like gasoline and diesel, were spilled or dumped.
    Excess glue and/or primer inside the pipe at the glue joint could also cause the same problem.
     

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