New sumergible pump disconnect problems

[George61p]

I had a new well drilled and new sumergible pump system installed. After a little bit of pumping water, there was no more water from the well. The installers pulled it out of the well and it seems that when the pump was started it unscrewed itself from the pipe connection. They put it back again, and the same problem occured again. What can be done from keeping the pump unscrewing itself out of the pipes?

 

[NHmaster]

There should be a torque arrestor installed near the pump for one, but the big question is how much experiance does the well guy have?

 

[Sponsor]

 

[Valveman]

I hate torque arresters. Just something to help your pump get stuck and ruin the well. One start will not unscrew the pump from the pipe. It takes multiple and excessive numbers of starts to unscrew a pump. I am guessing they installed a very small pressure tank, which is what causes excessive cycling on and off.

Solve the original problem, which is cycling on and off, and you don’t need torque arresters, and the pump won’t come unscrewed.

 

[George61p]

The well guy said it was because the pipe was PVC Sch 80, and he said he might need to replace a section down there with a steel pipe. Would that be a solution?

 

[Valveman]

If the Sch 80 is threaded you can't beat it. If they glued on a male adapter for threads it will come unscrewed much easier. What size tank and is the pump cycling?

 

[NHmaster]

Really? I've never heard that, but then everything up here is in 8" steel case so getting stuck is pretty rare. I'm still wondering about the installation though.

 

[George61p]

The PVC pipe is threaded, and there are 15 sections of 20 feet length for a depth of 300 ft. The storage tank is 50 gallons. The pump motor unscrewed after about 5 starts.
Guys thanks for your help, I am very new to submergible pumps, so all the replys help.

 

[Gary Slusser]

A torque arrestor shouldn't be used because they can prevent the pump from coming out of the well when it needs to but, an arrestor isn't going to stop a pump from unscrewing off the drop pipe anyway. If you think about it, it will hold the pipe still from rotating with the pump when the pump comes on, that's what they are supposed to do. Although I've not heard of pumps unscrewing themselves before.

IIRC most if not all pumps rotate CC. Which would tighten them onto the male adapter or end of threaded pipe.... unless the fitting or pipe had left handed threads.

What am I missing? If the pump unscrewed how did they pull it out of the well?

I think just the other day I read something about reversing the hots if the pump rotated CW.

 

[Waterwelldude]

When a submersible pump starts. It will try to unscrew off the pipe.
If there is pipe dope on the pipe.
Clean it all off.
Using pipe dope or teflon tap is just stupid. Do not use any type sealer on a submersible pump.

Just make the pipe up tight.


Travis

 

[George61p]

Gary Slusser
The pump remained attached by the 3 electrical wires and the duct tape which they used to attach to the pump and PVC pipe and it pulled out together with the last pipe. I agree with you that the pump should rotate CW when it starts and should attach itself more to the PVC pipe. I believe my pump is rotating CC when it starts and thus the problem. What do you mean by reversing the hots? The pump wire has a red, black and white wires. If the pump is made to rotate in the opposite direction, will it still pump the water as it should?
Thanks

 

[Waterwelldude]

A single phase pump can not be reversed..
If your pump came with a control box with a capacitor and relay.
The wires for the pump can not be moved or changed in any way.

 

[George61p]

Waterwelldude:

Thanks for the information.

 

[Valveman]

Really just 5 starts? That is terrible. I agree with WWD, no teflon and no pipe dope, just makes it slicker. I always run threaded PVC dry into a steel or brass coupling. Plastic thread to plastic coupling is not good either.

 

[Gary Slusser]

Gary Slusser
The pump remained attached by the 3 electrical wires and the duct tape which they used to attach to the pump and PVC pipe and it pulled out together with the last pipe. I agree with you that the pump should rotate CW when it starts and should attach itself more to the PVC pipe. I believe my pump is rotating CC when it starts and thus the problem. What do you mean by reversing the hots? The pump wire has a red, black and white wires. If the pump is made to rotate in the opposite direction, will it still pump the water as it should?
Thanks

I had to look up what I was referring to and it's true, you can't reverse a single phase motor, only three phase motors. But there is something I can't recall about a 2 wire pump reversing itself a few revolutions at times when it has a problem starting; 3 wire pumps don't do that.

Do you have a 2 or 3 wire pump; 3 wire has a control box?

I have never heard of a submersible pump unscrewing itself off the drop pipe, until now. And why only on plastic unless not tightened properly? This must be very rare or a Texas thingy; Valveman and WWD both are from TX. Or urban legend stuff discussed at the pump supply house. But you and they say it unscrews so I guess they do.

And I would not use threaded plastic dry. To me that's asking for stress to crack the male threads. And your guy wants to screw a plastic male into metal pipe instead of the metal pump... I don't see a difference except the joint would be 20' higher. What's the advantage to that? The metal pipe and sch 40 or 80 PVC isn't going to take up any twisting.

So let us know how it goes.

 

[NHmaster]

Got to agree with Gary here. I have never seen a pump unscrew itself so there has to be some underlying problem. As for the motor being in reverse, it wouldn't pump even if it could happen. Maybe the guy tightening the pump on to the pipe needs a few trips to the gym

 

[Valveman]

It is not just a Texas thing. I see this happening all over the country. I have fished out pumps that unscrewed themselves from 1" pipe up to 6" pipe. You probably don’t see it very often because you use poly pipe. Poly pipe flexes more so the pump doesn’t unscrew. But I do see a lot more damage to the drop wire on poly because of this flexing of the pipe. Rigid pipe like steel and sch 80 PVC does not give, and the pump will come unscrewed. All pumps in the US spin the direction to unscrew on start up. Reversing them is not an option or the impeller is spinning the wrong way and won’t pump water.

It has always been a pump cycling excessively that causes it to unscrew itself. A water logged tank or simply a tank that is to small without a CSV is the main cause.

I have run dry PVC threads into steel or brass coupling thousands of times without problems. Teflon or pipe dope causes the threads to be slick and will either tighten down farther than they should, or will come unscrewed easier than they should.

Dry PVC threaded into a brass or steel fitting will "pop" a couple of times when it is tight. You don’t have to tighten anymore than this and it won’t come unscrewed easily.

 

[Gary Slusser]

I'm just sayin'... in all the years I've done pumps and read complaints from owners online, I've never heard of a pump unscrewing itself until now. And for low pressure complaints, IMO, PVC and unscrewed pumps should be mentioned as a possibility consistently.

Yes in PA PE pipe is the norm but holes rubbed in it is not a problem, I do not believe I ever saw one but, the cable being worn in spots is a problem IF you don't use cable guards and/or tape every 10-15', and we have 6" rock bore wells. And rock will damage pipe etc. must easier and more likely than a casing in a sand and gravel screened well will.

BTW, last night while reading up on this, I found a great troubleshooting manual on Gould's site. You really have to dig to find things there but, it's the best troubleshooting manual I've ever seen; lots of graphics/pictures. But it doesn't mention anything about unscrewed pumps...

 

[NHmaster]

BTW, last night while reading up on this, I found a great troubleshooting manual on Gould's site. You really have to dig to find things there but, it's the best troubleshooting manual I've ever seen; lots of graphics/pictures. But it doesn't mention anything about unscrewed pumps...
__________________
See, I told you so. They also publish the same manual in a nifty waterproof pocket model. I have 2 cases

 

[Teets]

I've haven't had this happen yet in installing pipes up to 2" on a pumping systems. I've used a combination of teflon tape and pipe dope or just one or the other on male threads on the male threads that screw into the pumps. Maybe I've been lucky, but if it's tight enough this should'nt happen. I think it's due to the installer. But I've been known to be wrong before. I'm curious what other installers follow as their normal installation procedures. Please chime in.

 

[Waterwelldude]

It is mostly a larger hp pump problem. The higher the hp the higher the twisting power.
It does not happen very often on smaller pumps unless, like Teets said, It points to the installer not really knowing what he/she is doing.
I see this a lot with new guys trying to work on wells, and not knowing what to do and what not to do.

I have seen tape and dope on threads that never come off, or even loose.
Its just not a good idea to put anything on the pipe because it (can) come off because of the backward twist of the pump.


Oh, No its not just a Texas thing.
However I do think our pumps have more power than the northern pumps.
Maybe that's the cause.

Travis