Pipe in Well keeps bursting

Discussion in 'Pumps and Tanks Well Forum & Blog' started by 3388linda, Jun 22, 2006.

  1. 3388linda

    3388linda New Member

    Messages:
    5
    Boy, I hope there is someone who can help. Our new 441' well burst the schedule 20 pvc pipe right above the pump. Installer fixed it by installing schedule 80 pvc pipe above the well. Two weeks later, it burst again. Installer fixed it by installing 1" galvanized pipe above the well pump. Today, no water again. This always happens when I am using the wash machine or immediately after the washer shuts off???(I don't know!) I'm at my wits end and haven't had water three weekends out of four.(I know...waagh but I have a little boy and no family nearby) HELP! PLEASE! The installer has now 'had it'...and he's workin' us in. The idea of no water again is so depressing.
  2. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    Valveman

    Are you sure its not Sch 120 pipe? Sch 20 does not sound right to me. Do you have any info on the pump. (size, model number, horse power, anything) My best guess from what you are saying is that the pump is just barely big enough to pump from 441'. So after you run it a little and draw the water deeper in the well it may not be able to build up to the shut off point of the pressure switch. Pump still running, water in pump gets hot, pipe starts melting and blows off. The galv pipe won't melt so the pump probably got hot enough to melt the impellers and lock up this time. The plastic pipe blowing off probably saved the pump first two times. Doesn't matter though, if this is what is happening you need a bigger pump anyway.
  3. 3388linda

    3388linda New Member

    Messages:
    5
    Hello Valveman. I was wrong about the first pipe. It was schedule 40, went to 80, then to galvanized. The pump is 1 1/2 HP 12 gpm, Aeromotor. If we have to replace the motor, can you suggest a motor and what size pipe should be installed. The first pipe near the pump is all that has been replaced everytime. Thank you so much for your time and patience.
  4. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    http://www.aermotor.com/pdf/A5865WS_T_Max_Series.pdf

    The Aermotor 12 GPM 1.5 HP pump is rated at 375 ft of head at 12 GPM.

    A better choice would be to put the 8 GPM rated pump head on the 1.5 HP motor.

    The 12 GPM pump delivers only 6.8 GPM to a 60 psi tank at 400 ft to water. It provides 560 ft of head at minimum recommended flow of 6 GPM.

    The 8 GPM pump on the same motor delivers 6.4 GPM to a 60 psi tank at 400 ft to water, but provides 620 ft of head at 4 GPM minimum recommended flow.

    Given your experience, I would put the 8 GPM pump head on the 1.5 HP motor and stay with the steel pipe.

    If you really need 12 GPM delivered to your tank at 60 psi shutoff, you would need to go to something like the Goulds 10GS30, which is a 3 HP pump. There may be better matches to your needs, and Aermotor might make a better pump series than you have, but it would take some looking to find it.
  5. 3388linda

    3388linda New Member

    Messages:
    5
    Thank you, Bob. We have a 30-50 with a low pressure cut out switch. Would it help if went to a 20-40 pressure switch? My husband is searching for answers that don't cost so-o-o-o much. We very much appreciate everyone's help.
  6. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    Your 30-50 switch should be adjustable to 20-40. Be sure to drop the precharge pressure (empty tank condition) to 18 psi if you lower the start to 20.

    Who picked the pump? If your well man picked it, he has some responsibility for getting the correct pump.

    If you are paying for a new pump, then I suggest putting a smaller pump (Less GPM, more stages, more pressure) on the same motor. Something like the 8 GPM Aermotor or the pump end for a Goulds 7GS15. But the final selection should be made by someone who knows the facts about the well.

    Your well person should be able to tell you what the depth to water is when the pump is running. That is information that should be used in selecting the pump.
  7. 3388linda

    3388linda New Member

    Messages:
    5
    Hi, Bob. Our well man gave us a list and sent us to the local plumbing supply house to purchase the pump, pipe, etc. He is supposed to come tomorrow but who knows. He's a proud old guy that's been in the well buisness all his life and when my husband tried to talk to him about increasing pipe size, well, he got testy. We are between a rock and a hard place because we need him...and he knows it. He talked about the motor getting hot and tomorrow he implied he is coming to pull the pump and pipe, and he is also going to drill holes in the 4" PVC liner to allow water to circulate around the hot pump. What would you do? All my best, Linda
  8. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    Drill holes in a 4" PVC liner to let water circulate around the pump? In a 400 ft well? I'm confused! Maybe one of the well or pump guys can come on board.

    A submersible pump is usually set above the level where the water comes into the well. When the well pumps, it pulls water up past the motor, keeping the motor cool.

    Your plastic pipes didn't fail because the motor got hot; they failed because the pump was spinning away without pumping any water, so the water boiled and weakened the pipe. It was probably not pumping any water because it wouldn't put out enough pressure to move the water from the well to your tank.

    If you can do it without him feeling insulted, I would ask some questions:

    What is the level of the aquifer where the water comes into the well?

    What level is the pump set at?

    What is the static water level, and what is the water level when pumping?

    If you need a new pump, and you are paying for it, I would put the smaller capacity pump head, with higher pressure, on the motor. It will cost a little more because it has more stages, but you shouldn't need a new motor.

    With the smaller pump head, the 1" pipe is probably OK.

    If he is paying for the pump because he didn't specify the correct pump, let him keep doing it until he gets it right.
  9. 3388linda

    3388linda New Member

    Messages:
    5
    Thank you again. I'm going to print all this and allow my husband to absorb this information before the wellman comes. You've been wonderful. We appreciate your time and patience. Linda
  10. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    I hate to say this, but I think you need a different pump guy. Does anyone know how much water this well can produce? The fact that you have a low pressure cut off switch on your system suggests a low flow well.

    I can't imaging any pump man hanging a pump on SCH 40 pipe. Especially since you have to glue the joints. Where the SCH 80 we use has threads. This way, you don't lose the pump in the well.

    If this guy drilled the new well we are talking about, maybe he should have stopped there and let someone else handle the pump end. And if he did drill the well, he is responsible for installing the right equipment.

    The pump I would recommend is a 4 gpm 1hp. It poops out at 65 psi near the bottom of your well and may very well not over pump the well. I would recommend the Cycle Stop Valve to insure this and electronic motor protection just in case.

    bob...
  11. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    Valveman

    That 12 GPM 1.5 HP Aermotor would have to be worn down by 10% not to be strong enough to build up and shut off at 60 PSI. Unless someone made a mistake and put a 1 HP 14 stage on the 1.5 HP motor instead of the 19 Stage 1.5 HP pump end, it should be able to build to 60 PSI and shut off. The 4" liner sounds like a motor shroud. We have to use those in our area because we set the pump at the bottom of the aquifer and all the water feeds the pump from above. "Drilled holes" in a shroud would have to be completely below the motor or it will make the cooling flow worse for the motor. Also have had 240 volt motors hooked up wrong and only getting 120 volts. In this case the motor would run but not build enough pressure to shut itself off causing overheat. Also had this happen if it pumps the well dry. Usually have to be using more than a washing machine for this to happen but still possible. Should be able to tell if the old PVC pipe got hot because it will look pregnant close to the threads.
  12. Gary Slusser

    Gary Slusser That's all folks!

    How many loads of laundry are you doing one after the other? What other use, showers etc. before laundry maybe?

    The low pressure safety pressure switch says you have a low producing well; water conservation is in order. So spread the laundry out over a number of hours or do a load a day instead of all on the same day or you may continue to have problems.

    IMO sch 40 PVC shouldn't be used for drop pipe, especially at the depth of your well although I don't know where the pump is set, the static water level etc..

    I would want the galvanized removed. It rusts and blocks up over time plus it adds iron to the water.

    There is no reason to increase the ID of the drop pipe over 1". We use 1" (PE of sch 80 PVC) on wells/pumps to over 500' deep (in rock bore wells). Of course that assumes the pump is sized correctly for that depth and the building's water volume needs and the pressure that is required. He may have gotten "testy" because of you/hubby insisting you wanted to buy the materials and increased ID pipe. I can feel his pain but how was it you got to buy the materials?

    His 4" pvc is for proper cooling of the motor; a motor tail piece. As long as there is water over the pump inlet, and you have a rock bore well, the water will be coming down over the pump's wet end and the motor will not have water flow over it and it will get hot. Rock bore wells have recovery water running into them from anywhere form the end of the casing to the bottom of the well, and in all wells, you'll use stored water before recovery water from the bottom of the well. That assumes you pump more than the recovery rate gpm. Usually the thermal overload in the pump motor will open and shut off the motor when it gets too hot. It sounds as if yours is not doing that. Then the pipe gets hot and fails; or the water temp raises sufficiently to cause the PVC to fail. It doesn't take much heat to cause PVC to fail.
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