Submersible Pump Torque Arrestors? Are they needed?

Designie

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I have got mixed opinions from books and such on this. Should I put a torque arrestor on the poly pipe? My pump will be at about 220' down, 1 hp pump.
 
If you use a torque arrestor in an uncased well it will likely be more difficult to pull the pump in the future. Reaon being, besides hanging up in the borehole it also can collect small bits of rock flaking off the borehole above it.

I am having this exact problem now. Safe to say I won't be using a torque arrestor on the new pump.
 
"Torque arrestors are recommended for installations that use PVC drop pipe for three reasons. The first is that most pumps rotate in a direction that will cause the drop pipe to unscrew. A torque arrestor keeps the pump snug in the well casing reducing the possibility that the pump starting torque will result in any right hand thread loosening. It is attached to the drop pipe right at the pump, then it is expanded until it fits snugly in the well casing.

The second reason a torque arrestor is used is to keep the pump centered in the well. Not all wells are straight, a pump that is running up against the well casing may experience motor cooling problems and hydraulic imbalances. A pump hanging on plastic pipe will tend to move around and collide with the well casing which can result in abrasion to the pump and motor housings, damaged wire or damaged well casing.

The third and most important reason is that fatigue from repeated start-up torque will occur in the PVC and can cause the pipe to break."

So you need to handle the unscrewing issue and the centering issue.

I guess the pipe breakage issue should be balanced against the objections raised in this thread. Some pipes may handle fatigue better than others, over a lifetime of thousands of pump startups.

Another way to look at this is to ask, Of all the ways pump and well systems fail, how near the top of the list are failures due to pipe flexing?
 
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I can't comment on the frequency of pipe/pump damage, but I would rather lose a pump than lose the entire well (if the stuck torque arrestor seals the bore above the water table). And losing the pump could be avoided by running wire rope alongside the drop pipe, although you would still need to repair the damage.

Regarding the twisting force causing breakage that is probably motor HP dependent to some extent.
 
If there is a system to spin the pump RPM up slowly, then there will be no more pipe fatigue due to start up torque.
 
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Actually some of the variable speed type systems that “spin up slowly” cause more torque problems than normal type pumps. For instance the Franklin Sub Drive and Mono Drive systems can actually cycle about 45 times per minute. Even though they “spin up slowly”, cycling 45 times per minute, is 64,800 times in 24 hours, or about 2 million times per month. Usually I see the pump shaft break or the drop wire wear out from slapping against the casing or drop pipe. However, the pipe also sees this number of torque events and could also cause problems, if the pump shaft doesn’t break first.
 
And you're both in Lubbock. . .I was only 408 miles SE of you, in SA, as a "guest" of the USAF.
 
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we are required by code to use them. I have heard of folks having problems pulling pumps because of the arrestor but I have pulled many many pumps over the years and the arrestor has never been an issue. We are also required by code to use a safety rope of some sort.
 
Safety rope ... curious, do you use wire "rope" (stainless cable) or poly rope? Is it used to actually pull the pump (instead of the pipe)? Do you clamp it to the drop pipe at the well head?

The pump installers and supply house I deal with here in NC say no one uses rope or cable. But it would seem to be a good idea.
 
Wally,
Have you pulled pumps with arrestors out of uncased "rock" wells with no problems?
Around here, the local pump guy(s) do not want to use arrestors or spiders on a rock
well that is uncased. I'd like your opinion.
 
If you like buying wire, don't use torque arrestors.

Look at it like this, you have a 200', 300' or more run of flexible pipe hanging in a well that is no where near perfectly straight. That well has rough spots on the rock, without torque arrestors to limit the rotation and control the whipping, how can you possibly expect the wire to not get shredded?

Roger,

We pull pumps everyday that have torque arrestors on them. It maybe possible that they don't use them because of the type of rock, soft, wants to cave in etc. in that case the well should be cased or sleeved with 4" PVC. It's also possible that the standard practice is to install a jobs with a limited life expectancy.
 
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I sort of agree with Roger. If you have 300’ of flexible pipe, single jacketed wire, and a regular pressure tank system that is “whipping” every time the pump cycles on and off, you can’t put enough torque arrestors to stop the wire from chaffing.

However, if you have double-jacketed wire and use a Cycle Stop Valve, the pump won’t cycle on/off enough to wear out the down hole wire. I haven’t needed a torque arrestor in 22 years since I started putting a CSV on every pump installed. Then you don't have to worry that torque arrestors will stick the pump in the well no matter the condition of the well.
 
I sort of agree with Roger. If you have 300’ of flexible pipe, single jacketed wire, and a regular pressure tank system that is “whipping” every time the pump cycles on and off, you can’t put enough torque arrestors to stop the wire from chaffing.

However, if you have double-jacketed wire and use a Cycle Stop Valve, the pump won’t cycle on/off enough to wear out the down hole wire. I haven’t needed a torque arrestor in 22 years since I started putting a CSV on every pump installed. Then you don't have to worry that torque arrestors will stick the pump in the well no matter the condition of the well.

If I may add to this, might also consider a pressure tank. Will expand the life of ur pump for many reasons. One being , it won't have to cycle as often. Especially nice if u use it often enough.
 
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