Water Wells and pump technology

[Fruit Trader]

38 minutes ago, grollies said:

My borehole has a very heavy Franklin submersible pump 50m depth in a 75m deep borehole. It certainly does not hang by the pipe nor the electric supply cable.  

Our farm pump hangs in the bore on 25mm PVC pipe at around 35M there is no safety or strain line.

The pump shown in post 10 video hangs on its pipe at around 50M.
 

[owl sees all]

I think there needs to be some clarification on the submersible pump.

 

Firstly; at the top of the pump, there will be two eyes and it is they, that a sturdy nylon, or similar, cable/rope is attached. The nylon cable/rope is tied to both eyes and they then become 'one' after about half a metre up. It is important that this cable/rope is:

 

a/ not going to rot away

b/ man enough to suspend the pump, and PVC, and cable

c/ independent from the PVC and cable, which are as one due to being clipped together in the bore. The real weight of the submersible is first when being lowered before it hits water (or raised) and when in operation the extra water from water table head to surface in the PVC.

 

secondly; (this is a personal view) the PVC pipe does not have to be the top grade with the exception of the section that is going to be out of the ground (top section) and the male PVC connector that allows the first pipe to be connected into the pump.

 

thirdly; the depth to which the submersible is going to rest is worked of beforehand and the electric cable attached (usually 30 metres) might need to be lengthened, even doubled, with another similar cable. The actual connection needs to be waterproofed (seriously waterproofed).

 

fourth; it is more than a one-man job to lower the pump. Someone needs to be in control of the rope/cable. Another needs to glue the PVC and another needs to do the cable tie work. It is all very steady-as-she-goes.

 

I've done five on our land and assisted on others. Hope my experiences can help anyone.

 

Just as an addendum; I put a small loop into the rope every few of metres. This was to enable a bamboo or rod to be slipped in, put across the bore PVC, and thus relieve a worker when lowering down the bore.

Edited January 4, 2019 by owl sees all

[Fruit Trader]

13 minutes ago, owl sees all said:

I think there needs to be some clarification on the submersible pump.

No clarification needed. Submersible pumps can hang on PVC pipe. In post 26 you said - "a submersible pump is not hanging from a PVC pipe"

 

I suggest you watch a few installation videos.

Not all pumps have facility to install a strain line.

 

Personal experience is not always the norm. 

[owl sees all]

13 minutes ago, Fruit Trader said:

No clarification needed. Submersible pumps can hang on PVC pipe. In post 26 you said - "a submersible pump is not hanging from a PVC pipe"

 

I suggest you watch a few installation videos.

Not all pumps have facility to install a strain line.

 

Personal experience is not always the norm. 

The submersibles pumps have holding eyes built into them. I've not seen one that didn't have. They are there for a reason. Of course 20kg pumps can be hung from the PVC pipe alone. This is folly IMO. You certainly don't want to be lowering or lifting a pump to/from 50 metres down by the PVC or the electric cable.

[grollies]

48 minutes ago, Fruit Trader said:

Our farm pump hangs in the bore on 25mm PVC pipe at around 35M there is no safety or strain line.

The pump shown in post 10 video hangs on its pipe at around 50M.
 

Works for you, it's just not the way I, personally, would hang a submersible pump....

[Fruit Trader]

1 minute ago, owl sees all said:

The submersibles pumps have holding eyes built into them. I've not seen one that didn't have. They are there for a reason. Of course 20kg pumps can be hung from the PVC pipe alone. This is folly IMO. You certainly don't want to be lowering or lifting a pump to/from 50 metres down by the PVC or the electric cable.

Again. Personal experience is not always the norm. Not all pumps have safety line hooks. 

 

Safety lines. Lets try a video again before we end up back peddling on pump weight.

 

 

 

 

 

[Artisi]

2 hours ago, owl sees all said:

A submersible pump is not hanging from a PVC pipe. Nor is it hanging from the cable.

"if hanging" 

[Fruit Trader]

4 minutes ago, grollies said:

Works for you, it's just not the way I, personally, would hang a submersible pump....

I have no problems with personal choice and understand why you have installed a safety line. I do however have a problem with people who make sweeping statements about how it should be done.

[Artisi]

1 minute ago, Fruit Trader said:

I have no problems with personal choice and understand why you have installed a safety line. I do however have a problem with people who make sweeping statements about how it should be done.

Or sweeping statements of pump hydraulic capabilities etc. 

[sometimewoodworker]

3 hours ago, Artisi said:

The irrelevance is making statements that ejector pumps cannot operate any deeper than 30 metres together with other wrong information. 

It's a shame you didn't read the information, it was for standard off the shelf pumps - don't know if available in Thailand, the Davey unit could be. 

 

find one that does in thailand

[Fruit Trader]

15 minutes ago, Artisi said:

Or sweeping statements of pump hydraulic capabilities etc. 

I guess that will be the short range jet pump ???? Cant say I have seen anything over 35M off the shelf in LOS but they are available for up to 6000 M

Edited January 4, 2019 by Fruit Trader

[bankruatsteve]

It seems to me that a "safety" rope would only be necessary in shallow installations and where the piping might be flexible.  Any rope small enough to fit in the bore along with the pipe  would not be capable of bearing the entire load over time.  It would stretch until the pipe takes over or it would break.  The electric cord should never bear any weight.  But, the pipe is the load bearer.

[owl sees all]

18 minutes ago, Fruit Trader said:

I have no problems with personal choice and understand why you have installed a safety line. I do however have a problem with people who make sweeping statements about how it should be done.

I take it you are in Thailand. There are some installers that cut costs and corners, but IMO it is better to install the submersible in a good way. I've watched the video, and it's OK. But that is not how it is usually done here. I like to utilise the Thai methods, then add a bit of security and safety. If the installation is for yourself, it is folly, IMO, to not use a support cable/rope.

 

And I must again say, I've never seen a deep well, submersible pump here, that didn't have support eyes. What do you think they are for; hanging up in the showroom?

[grollies]

20 minutes ago, bankruatsteve said:

It seems to me that a "safety" rope would only be necessary in shallow installations and where the piping might be flexible.  Any rope small enough to fit in the bore along with the pipe  would not be capable of bearing the entire load over time.  It would stretch until the pipe takes over or it would break.  The electric cord should never bear any weight.  But, the pipe is the load bearer.

You've heard of steel wire rope right?

[Artisi]

34 minutes ago, sometimewoodworker said:

find one that does in thailand

If you are really interested, Davey have an agent in Thailand, plus you can also try Grundfos Thailand. 

[owl sees all]

35 minutes ago, bankruatsteve said:

It seems to me that a "safety" rope would only be necessary in shallow installations and where the piping might be flexible.  Any rope small enough to fit in the bore along with the pipe  would not be capable of bearing the entire load over time.  It would stretch until the pipe takes over or it would break.  The electric cord should never bear any weight.  But, the pipe is the load bearer.

2

Going by the posts on this, there are a few deep well submersible pumps hanging (suspended) by just the PVC.

 

IMO this is just not good practice. I do have a submersible pump that is designed to pump from just below the surface of the water in a lake or pond that has a different attachment. But we are talking deep water and we are in Thailand after all**.

 

This thread is for information and advice. And I can only give what I consider to be a 'best practice' in this regarding advice.

 

** I've seen PVC pipes in the mud and only a quick rub on the sleeve to clean them. If the glue does not take properly and a joint separates 30 meters down, it is easily possible that a catastrophe could occur.

 

When the pump is in position the whole thing is suspended on the holding cable/rope. The PVC would be above the well-cap and be free to move about.

Edited January 4, 2019 by owl sees all

[Artisi]

7 minutes ago, owl sees all said:

Going by the posts on this, there are a few deep well submersible pumps hanging (suspended) by just the PVC.

 

IMO this is just not good practice. I do have a submersible pump that is designed to pump from just below the surface of the water in a lake or pond that has a different attachment. But we are talking deep water and we are in Thailand after all**.

 

This thread is for information and advice. And I can only give what I consider to be a 'best practice' in this regarding advice.

 

** I've seen PVC pipes in the mud and only a quick rub on the sleeve to clean them. If the glue does not take properly and a joint separates 30 meters down, it is easily possible that a catastrophe could occur.

Best practice of course would be steel pipe etc, but this is Thailand and blue PVC rules, it surprises me that Thai condoms are not made from it as well. 

Edited January 4, 2019 by Artisi

[steve73]

Never a good idea to hang the pump from either the cable or the pipe. 

 

Plastic coated steel cable, of sufficient strength should be used... and inspected regularly (perhaps yearly) for signs of corrosion/damage.

It needs to be able to lift the weight of the pump, the outlet piping full of water, plus the weight of the cable... all of which adds up especially if it's very deep. (ie. more than a few 10's of m)

 

If there's any sand/solids in the pumped fluids, it can wear the PCV pipe just above the pump outlet over time, making it necessary to replace this section, and obviously it's then too weak to lift the pump. 

 

A friend of mine had a very expensive submersible pump installed in a relatively shallow borehole (unnecessary IMO, as he could have used a surface pump).  In about 2 years it had sucked in enough sand/grit to fill his 5m3 storage tank, as well as damaging the outlet pipe.

 

Better to use a small pump that operates for a longer period and at a lower flowrate, than a large pump that only operates for a short period, but at a much higher flowrate.  Much cheaper to install, and less chance of damaging the bore-hole sand-face, or the pump & piping, but many contractors will try to sell you the "larger is better" so they can make more profits.

 

[bankruatsteve]

1 hour ago, grollies said:

You've heard of steel wire rope right?

Same issues.  The purpose of the safety rope is to preclude losing everything before assembly is complete.  It is not for bearing the load.

[grollies]

12 minutes ago, bankruatsteve said:

Same issues.  The purpose of the safety rope is to preclude losing everything before assembly is complete.  It is not for bearing the load.

Given the choice between hanging a 20kg submersible pump 50m down a 6" borehole I'd much rather hang it from a 5mm steel cable than bear the load on 1 1/4" PVC pipe with glued joints every 4m or, God forbid, the electric cable.

 

But that's just me, like Fruitrader says, each to their own.

[bankruatsteve]

10 minutes ago, grollies said:

Given the choice between hanging a 20kg submersible pump 50m down a 6" borehole I'd much rather hang it from a 5mm steel cable than bear the load on 1 1/4" PVC pipe with glued joints every 4m or, God forbid, the electric cable.

 

But that's just me, like Fruitrader says, each to their own.

I'm pretty sure 50m will need more than PVC with glued joints and a 5mm steel cable if it is expected to still be there after 1 year.  The cable would stretch until the pipe picks up the load anyway.

[grollies]

36 minutes ago, bankruatsteve said:

I'm pretty sure 50m will need more than PVC with glued joints

Why? 50m produces a static head at the sub pump of 5bar. Used 13.5 bar pipe.

36 minutes ago, bankruatsteve said:

and a 5mm steel cable if it is expected to still be there after 1 year.  The cable would stretch until the pipe picks up the load anyway.

Disagree but there ya go.

 

Just out of interest, since 5mm steel cable is no use, you wouldn't use the electric cable (obviously) and PVC pipe is no good for a 50m deep well, either for hanging or water delivery how exactly would you yourself install a submersible pump in, say a 70m deep borehole?

[bankruatsteve]

36 minutes ago, grollies said:

Why? 50m produces a static head at the sub pump of 5bar. Used 13.5 bar pipe.

Disagree but there ya go.

 

Just out of interest, since 5mm steel cable is no use, you wouldn't use the electric cable (obviously) and PVC pipe is no good for a 50m deep well, either for hanging or water delivery how exactly would you yourself install a submersible pump in, say a 70m deep borehole?

I was thinking 50m of water in PVC would be really heavy but a rough calculation would have it at about 180 kg for 1-1/2" plus pump.  (?)  So maybe glue joint would be OK but thinking metal screw connectors better.  I don't know what BAR has to do with dead weight.

 

If you don't think steel cable stretches with load, google it.  As a safety rope steel or nylon is going to be just fine.  But, after not much time, it will not be bearing the load.

 

Cheers

[grollies]

11 minutes ago, bankruatsteve said:

I was thinking 50m of water in PVC would be really heavy but a rough calculation would have it at about 180 kg for 1-1/2" plus pump.  (?)  So maybe glue joint would be OK but thinking metal screw connectors better.  I don't know what BAR has to do with dead weight.

 

If you don't think steel cable stretches with load, google it.  As a safety rope steel or nylon is going to be just fine.  But, after not much time, it will not be bearing the load.

 

Cheers

Yep, I understand that the cable stretches. Which is why I checked the load at the wellhead a few days after installation. The wire stretches two ways, one as the steel layers compress under load and secondly due to its elastic properties. But it won't continue stretching as the weight of the pump and pipe reaches nowhere near its yield point.

 

If you don't know what 'BAR' has to do with static head pressure I'm not explaining it to you, sorry.

[bankruatsteve]

4 minutes ago, grollies said:

If you don't know what 'BAR' has to do with static head pressure I'm not explaining it to you, sorry.

Dead weight of 50 meters of PVC filled with water has nothing to do with pressure.  

[rvaviator]

Yep, I understand that the cable stretches. Which is why I checked the load at the wellhead a few days after installation. The wire stretches two ways, one as the steel layers compress under load and secondly due to its elastic properties. But it won't continue stretching as the weight of the pump and pipe reaches nowhere near its yield point.
 
If you don't know what 'BAR' has to do with static head pressure I'm not explaining it to you, sorry.

Hmmmm .... are you saying that the pressure during the pumping action will force the pump downwards and add to the statice load of the water in the pipe and mass of the pipe ?


Sent from my iPad using Thailand Forum - Thaivisa mobile app

[grollies]

16 minutes ago, bankruatsteve said:

Dead weight of 50 meters of PVC filled with water has nothing to do with pressure.  

I never spoke about the weight of water in the pipe. I did post about pipe pressure rating for deep well boreholes. I think I'll leave it there thanks.

[grollies]

2 minutes ago, rvaviator said:

Hmmmm .... are you saying that the pressure during the pumping action will force the pump downwards and add to the statice load of the water in the pipe and mass of the pipe ?


Sent from my iPad using Thailand Forum - Thaivisa mobile app

Whaaat? There are obviously a couple of people here who don't understand pipe pressure ratings and the effect of static head pressure.

[Artisi]

9 hours ago, sometimewoodworker said:

With out bothering to read a document that is probably talking about industrial, commercial or city water pumps.

 

 I am talking about domestic usage in Thailand.

 

30 metres would not be considered high, something like an aquifer that you may need to drill deep but then gives a water level of less than 10 metres would be considered high

 

Any driller who is telling you that you can use a domestic JET pump available in Thailand over 30 metres is wrong 

 

If you want to pay hundreds of thousands of Baht or millions I'm sure many things are possible. Most people here don't want to pay over 10,000 some will go over that (17,000 is my pump cost) few up to maybe 40,000 nobody I know will go much if any over that for domestic use.

 

compare apples to apples, show details of a domestic well pump in Thailand that goes to your claimed depth of over 50 metres and I will be happy to accept that I'm wrong, otherwise do stop wittering on about irrelevant information. 

Hope you can take the time to read this documentation, the irrelevant information may well enlighten you. 

Grundfosliterature-6871.pdf

 

Edited January 4, 2019 by Artisi

[grollies]

OK, I'm going to try to explain static head, pipe ratings, pumping capabilities, borehole setup......tomorrow. I've had way too many Leos tonight!