Prev Page 3 of 6 1 2 3 4 5 Next » Please log in to reply 129 replies to this topic

[chownah]

Soap,
Usually(often) when you drill into a sand layer filled with water the water will rise up inside the bore.  If it rises enough then you can have a pump above ground to suck the water out.  If it does not rise enough then you will have to put a pump down inside the bore to push the water out....having check valves every so often will not work.  The water often rises to the level of the ground water (water table).  This varies from month to month and place to place.  I don't think that there are any pumps that can be placed down inside a 2 inch liner pipe....at least I have never heard of one but I could be wrong.

Chownah

[soap]

chownah, on 2007-02-16 07:39:38, said:

Soap,
Usually(often) when you drill into a sand layer filled with water the water will rise up inside the bore.  If it rises enough then you can have a pump above ground to suck the water out.  If it does not rise enough then you will have to put a pump down inside the bore to push the water out....having check valves every so often will not work.  The water often rises to the level of the ground water (water table).  This varies from month to month and place to place.  I don't think that there are any pumps that can be placed down inside a 2 inch liner pipe....at least I have never heard of one but I could be wrong.

Chownah

hello chownah
                   this was going to be my second question but i forgot to add.
  the water did come up the 2 inch pipe a few meters from ground level.
so with the 3/4 inch pipe do you still send it down to sand/water level  or just  send it down say about 8 metres
   thanks for your reply

[chownah]

soap, on 2007-02-16 10:41:44, said:

chownah, on 2007-02-16 07:39:38, said:

Soap,
Usually(often) when you drill into a sand layer filled with water the water will rise up inside the bore.  If it rises enough then you can have a pump above ground to suck the water out.  If it does not rise enough then you will have to put a pump down inside the bore to push the water out....having check valves every so often will not work.  The water often rises to the level of the ground water (water table).  This varies from month to month and place to place.  I don't think that there are any pumps that can be placed down inside a 2 inch liner pipe....at least I have never heard of one but I could be wrong.

Chownah

hello chownah
                   this was going to be my second question but i forgot to add.
  the water did come up the 2 inch pipe a few meters from ground level.
so with the 3/4 inch pipe do you still send it down to sand/water level  or just  send it down say about 8 metres
   thanks for your reply

Assuming that you are going with a ground level pump sucking the water up I would send the 3/4 inch pipe down 10.5 metres.  The absolute maximum that it is possible to even in theory suck water up in a tube (here on planet earth) is 10.33 metres so I would go a bit further because being longer makes virtually no difference and then for sure you know you have gone far enough.  This 10.5 metres would be measured vertically from the highest point in the suction pipe to the inlet at its lowest point down in the well.  I mention this because sometimes the suction pipe comes up out of the well and then goes down to the pump in which case you do not measure from the pump but from the highest point in the suction pipe which in this case would be above the pump.
Chownah
P.S.  Running the suction pipe all the way to or near the bottom would work fine too only it would cost more for the pipe and you would have a bit of extra flow friction due to the extra length of pipe...a small amount for sure.
Chownah

[lingling]

chownah, on 2007-02-16 07:39:38, said:

I don't think that there are any pumps that can be placed down inside a 2 inch liner pipe....at least I have never heard of one but I could be wrong.

Don't know if it is available or if it would work, but one idea would be to use some type of ejector device down in the well and then a normal pump on ground level. The ejector can be made small enough to fit in a 2" pipe. Just an idea...

[soap]

thanks chownah,lingling for the info,
i have enough 3/4 inch pipe to go down to the sand but i will leave it up to the thai guys who are doing the job how far down they will go,at least i know now were they are going
         thanks

[lingling]

I googled a bit on using ejectors in wells and that seems to be a common thing.

Something like this:
http://www.deanbenne...l-jet-pumps.htm

[Lickey]

Maizefarmer, on 2006-09-01 16:29:32, said:

BOREHOLES

Lots of us have water boreholes and there are some of us who would like a water borehole.

But you get boreholes and you get boreholes i.e. some will work good & proper for a long time, and some will be nothing but trouble trouble trouble….because the borehole industry in Thailand, like all industries, has its "cowboys".

Some things you can do and some things to look out for when selecting the right man to do the job.

1) Jump in the pickup and drive around a bit – check out who else around you has a borehole and have a chat with them. Find out:

- how deep the hole is
- how much water it produces p/day
- is it year round (or if it changes, by how much does it change).
- what pump do they use (submersible or plunger type – down to around 10m you can get away with a plunger type, much further you're best off with a submersible, they are more expensive)
- how long has it been in use
- lastly, who bored it and what did it cost.

Check out as many as you can around your village/area – that will give you a realistic idea of what you can expect to get from a borehole on your land. You may even want to get a sample of the water and test it yourself for nitrates/nitrites/ calcium ect ect (done easily & cheaply). If its just for the house and garden 3 cubic meters volume a day is fine – which you can pump out with a couple of truck batteries if you have no ac mains power. Yup, so boreholes in rural areas do make a lot of sense.

Generally you have 2 sizes in Thailand: for domestic use you don't need more than a 6" diameter borehole, but for agriculture use and small businesses you want 12" diameter borehole (that's not to say 6" won't do – it can, and often does – just that you'd be better off volume wise if it was 12" diameter).

Check too if you need permission – some areas you'll have to go off and have a chat with the local Phu Yai (village head or District Head at the local district office, and in other areas no-one cares) – but check. The only time you'll get a "no" answer is if you're in an area that is surrounded by industry and the ground water is known to be not safe, or if there is a ground water quota in your area which is been exceeded (there some areas around Bangkok like that, where some industries lift large quantities of H2O from the ground, but out in the "sticks" I have heard of no restricted areas for quota based reasons).

Now's the time to have a chat with the guys who dig the holes – and to take note what you have been told by others, compare it carefully with what the borehole digger tells you – because they can tell some tall stories – for every 10 boreholes dug, at least half of them won't be serviceable after 5 – 10 years and its usually because they weren't dug properly in the first place, not because there isn't any water.

So what are the problems:

1) Slurry Slurry Slurry – other than fuel it's the boreholers biggest expense, but it's the most important component in boring. It will determine how long the borehole lasts and it will determine how many times you have to lift your pump to take stones out the impeller or indeed, replace your pump. The slurry is a mud that is injected down the hole and (because of its density) is used to lift all the loose dirt and in particular the stones, out of the hole as it is sunk. A lot of cowboy borers just do not use it because it cuts their expense. It must be used. It also ensures that the side of the hole are consistant – it will seep into the uneven side wall forming a consistant smooth surface which consolidates the wall and helps to prevent it from collapsing in over time – nothing worse than having a borehole wall that has collapsed in at 30 meters and compressing part of the tube wall – stopping you from retrieving your expensive submersible pump to get the stones out the impeller! So when you go round to see the guy (always best to go & see him first – and then follow it up with a meeting at your place), just look around his yard to see if there are slurry settling tanks lying around. If he uses slurry he'll have settling tanks lying around because they like to collect it as it comes up, let it settle and pump it back down again. No tanks then ask him if you uses slurry. If he says not needed, then move on. IT IS NEEDED to do the job properly – simple as that.

2) Borehole tubing –you get borehole tubing and you get borehole tubing. The cowboys will use the thinnest stuff they can get away with. Go check out the tubing yourself – get a quote from the boreholer, then ask him what the tubing costs, get that taken off and go get it yourself – so you know what's been used and get advise from the hardware store as to what is good tubing and what is not. Don't skimp on the lining.

3) Joining the tubes in the hole: 3 methods – threaded, screwed, pvc adhesive. Use screws and you are asking to be screwed. They will rust if not stainless steel, which will mean if ever you have to lift the lining you will not be able to. If not correctly screwed in they can break, or just as bad – as someone else has reported: they stuck through so far into the hole in his case they prevented him from getting the pump down the hole. The sharps ends can also wreck havock on the power supply cable in the hole over time. PVC adhesive would be a better choice, but again, it's adhesive strength can breakdown over time which again will prevent you from lifting the tubes if you ever need to. End threaded tubes are the best – they form a good tight joint and wont separate.

4) Dropping the pump: if using a submersible use 2 (TWO) stainless steel wire cables – not one. If one snaps you're buggered – try lifting a 10kg submersible from 30 meters on it's power cable. Not wise. Use two cables so you have redundancy and ensure they are stainless steel not normal multi-strand wire steel.

5) Who to use: well, I assuming you have been speaking to the locals who have boreholes and they have all had theirs done by the same guy and they have all been going for 5 or 10 years,, then I guess that's a fair bet. But failing that, and having understood all the above will be adhered to, what else: well, ask the guy if he has hydrology maps for your area. All the professionals will have maps and water table data for your area and will be able to tell you the mean, low and high water table levels for your area, season to season for the last 20 years – something that has been and is monitored very carefully by the authorities all over Thailand.

6) Get a good concreate cap poured around the borehole at ground level – and have a lockable cap on the top of the tube (to stop rubbish getting into the tube and someone nicking your submersible pump – they do get nicked).

How deep will your borehole have to be – well, about as deep as those around you who have boreholes, but there is no average – each area, depending on its elevation above sea level will have its water table at a different height relative to the surface – and will be affected by the geology of the region. Some areas are as shallow as 6 – 10meters for good all year round water supply, and in other areas (like where I am) you have to go down 80 – 100 meters to get year round water. Clay areas shallow, chalky areas deeper, and the deepest boreholes are found in the sandstone and granite areas – which also give the best water as the sandstone acts as a brilliant filter. Chalky areas make the water real hard with calcium.

If anyone has their own "borehole experience" to add – go ahead.

Tim

Hi Tim, thanks for all the infomation on boreholes, very interesting reading, I would like your advice on some options i have, firstly we have a borehole with a submersible that pumps about 10 gallons a minute, enough for 1 sprinkler over a 20 mtr radius, apparantley the hole is 30mtr and even now in dry season keeps going all day, it has to pump water uphill 200mtr and irrigate 9 rai of papaya, and in the next few weeks want to plant 6 rai of banana, its a red clay soil and seems very water retentive, the borehole is 12inch, delivery pipe is blue 2inch, picking your brains now, is it possible to make exsisting hole deeper? or/and get a bigger pump? thanks for any advice you can give, Lickey..

[RasiMike]

Here in Issan, (Rasi Salai) we put in a 26 + metre bore, hit ('naam') at about 15 or so.... Total cost with 100 mm casing  ......3840 baht (3000 + Laos Khao quart yai neung). I pump continuously for approx 3 hrs/day and no problems over 2+ years. The water quality is a little suspect (odour) .....however the father-in-law, Pho yai etc. have no complaints about the Papaya, Phak,...Khoi? (banana), Tangmoor etc....... not to mention the size of our ducks. Drinking water comes from the roof .Perhaps the estimates posted on this thread may be due to the Farang factor or "geographical positioning"......... Or perhaps very good Thai-in-laws in my case?

[palm]

My Thai project manager was just quoted 120,000 baht for:

9" bore-hole
up to 100m deep (they said 50-70m is probably what we'll end up needing)
including submersible pump and motor etc
screw-together tubing
10% deposit
40% on completion and working after a few weeks
remaining 50% after 12 months if everything is still ok
will take about 10 to 20 days to do unless they hit a ton of granite (same price, their hard luck)

Location is Phitsnulok. Seems quite a fair deal to me?

I have about 120 rai to supply, and new lakes to build/fill etc.

[RamdomChances]

^ Palm, I think I paid 70-80,000 for mine, 6" hole, 2 hp pump can do about 10,000 l/hr all the fittings ect, it's about 60m but this is a few years ago.

Rasi mike, thats a remarkable low price, you can't buy a pump for that

[Gary A]

Years ago I lived in a village near Bangkok. The electricity went of on a regular basis for some reason. The water pressure was also so low that a pump was a necessity. During my morning shower before going to work, the power would sometimes go off and I couldn't even get the soap rinsed off me. Water eventually soaks up the air in the small pump tank and thats when you get what is called telegraphing. The pump cycles on and off causing a water pulse. The solution was buying an approximately 30 gallon stainless steel tank with a clear tube showing the water level. If the power went off I still had enough water to finish my shower and then some. It was easy to look at the sight glass once in a while and if the water level was too high a bicycle tire pump easily put more air into the tank. The stainless steel tank will last through several water pumps.

[salkhi]

greetings,
just a random one to see if anyone knows anything about
the ground conditions for a bore hole (for agricultural use) in Taptaan area, Uthai Thani...
Am drawing plans for an eco farm from uk at the moment, so am doing alot of guesswork,
thanks alot

[RamdomChances]

Sakhi you'd need to talk to the locals as the conditions vary so much

[sinom]

Chaps et al

very interesting thread.

I have recently installed a 45 m well at my house in Banglamung to service house and swimming pool and garden. My city water bill normally runs to about 2500 THB per month so the economics of installing a borehole system for 80,000 THB are fairly self evident.

The company I used performed a fairly professional job (for Thailand), installed a 6" jacket, with a 2" pipe insert with the pump attached. I can't remember the spec for the pump and it is now sunk down 45m. !! The pump was supplied with a box of tricks which includes a thermal overload circuit.

The water I get was tested and found to contain an excessive amount of particulates and slightly acidic.

So I've installed an active carbon filter system with particulate removal added. Tested the system and it's great ! I get perfectly clean water that's good for everything I need.

But........ here comes the problem ........... The pump runs inititially for about 5 minutes and then trips repeatedly on what I think is thermal overload.

If I leave it for a few minutes, perform a reset to the relay I can restart and get another 5 minutes. This is very frustrating.

The water coming of is fairly brown in colour and creates a small amount of mud sediment in my upstream screen filter. I was concerned that during construction some dirt may have gone back down the outer jacket and be fouling the pump. I can't fully remove the pump to inspect it without cutting up the 2" inner pipe on removal. So I removed it about two meters up and down to see what would happen. The result was that the pump ran for what seemed to be a little longer then tripped out again.

Does the collective experience on this thread have any advice on this?. My concern now is that the pump is under powered and stuggling to pump against a 45m head of water containing a degree of sludge and I will have to pull the whole thing out to inspect it, cutting up the pipe as I go, then possibly replace the pump, but not know if this is correct until the whole thing is back in place and I try again.

Thanks in advance

[Gary A]

sinom, on 2007-03-28 09:32:15, said:

Chaps et al

very interesting thread.

I have recently installed a 45 m well at my house in Banglamung to service house and swimming pool and garden. My city water bill normally runs to about 2500 THB per month so the economics of installing a borehole system for 80,000 THB are fairly self evident.

The company I used performed a fairly professional job (for Thailand), installed a 6" jacket, with a 2" pipe insert with the pump attached. I can't remember the spec for the pump and it is now sunk down 45m. !! The pump was supplied with a box of tricks which includes a thermal overload circuit.

The water I get was tested and found to contain an excessive amount of particulates and slightly acidic.

So I've installed an active carbon filter system with particulate removal added. Tested the system and it's great ! I get perfectly clean water that's good for everything I need.

But........ here comes the problem ........... The pump runs inititially for about 5 minutes and then trips repeatedly on what I think is thermal overload.

If I leave it for a few minutes, perform a reset to the relay I can restart and get another 5 minutes. This is very frustrating.

The water coming of is fairly brown in colour and creates a small amount of mud sediment in my upstream screen filter. I was concerned that during construction some dirt may have gone back down the outer jacket and be fouling the pump. I can't fully remove the pump to inspect it without cutting up the 2" inner pipe on removal. So I removed it about two meters up and down to see what would happen. The result was that the pump ran for what seemed to be a little longer then tripped out again.

Does the collective experience on this thread have any advice on this?. My concern now is that the pump is under powered and stuggling to pump against a 45m head of water containing a degree of sludge and I will have to pull the whole thing out to inspect it, cutting up the pipe as I go, then possibly replace the pump, but not know if this is correct until the whole thing is back in place and I try again.

Thanks in advance

You probably have a check valve (one way valve) installed just outside of the top of the casing. I would take the check valve out and allow the water in the pipe to backwash back down through the pump. Maybe even force more water down the pipe. That should clear any debris from the screen on the pump. To pull the pump a meter or so higher in the casing would also be a good idea. You should have some information regarding the pump capacity. Check to see if it is rated to push water the 45 meters. That is a deep well.

[Khonwan]

sinom, on 2007-03-28 09:32:15, said:

....., cutting up the pipe as I go, ....

I don't have a bore, but...it is my understanding that the inner pipe is threaded. Normal metal pipe is purchased in 6-metre lengths and are usually threaded. I suspect you have only pulled this pipe up a couple of meters and therefore have not seen the threads. Can anyone with a bore confirm this?

[sinom]

Gary A, on 2007-03-28 11:11:13, said:

sinom, on 2007-03-28 09:32:15, said:

Chaps et al

very interesting thread.

I have recently installed a 45 m well at my house in Banglamung to service house and swimming pool and garden. My city water bill normally runs to about 2500 THB per month so the economics of installing a borehole system for 80,000 THB are fairly self evident.

The company I used performed a fairly professional job (for Thailand), installed a 6" jacket, with a 2" pipe insert with the pump attached. I can't remember the spec for the pump and it is now sunk down 45m. !! The pump was supplied with a box of tricks which includes a thermal overload circuit.

The water I get was tested and found to contain an excessive amount of particulates and slightly acidic.

So I've installed an active carbon filter system with particulate removal added. Tested the system and it's great ! I get perfectly clean water that's good for everything I need.

But........ here comes the problem ........... The pump runs inititially for about 5 minutes and then trips repeatedly on what I think is thermal overload.

If I leave it for a few minutes, perform a reset to the relay I can restart and get another 5 minutes. This is very frustrating.

The water coming of is fairly brown in colour and creates a small amount of mud sediment in my upstream screen filter. I was concerned that during construction some dirt may have gone back down the outer jacket and be fouling the pump. I can't fully remove the pump to inspect it without cutting up the 2" inner pipe on removal. So I removed it about two meters up and down to see what would happen. The result was that the pump ran for what seemed to be a little longer then tripped out again.

Does the collective experience on this thread have any advice on this?. My concern now is that the pump is under powered and stuggling to pump against a 45m head of water containing a degree of sludge and I will have to pull the whole thing out to inspect it, cutting up the pipe as I go, then possibly replace the pump, but not know if this is correct until the whole thing is back in place and I try again.

Thanks in advance

You probably have a check valve (one way valve) installed just outside of the top of the casing. I would take the check valve out and allow the water in the pipe to backwash back down through the pump. Maybe even force more water down the pipe. That should clear any debris from the screen on the pump. To pull the pump a meter or so higher in the casing would also be a good idea. You should have some information regarding the pump capacity. Check to see if it is rated to push water the 45 meters. That is a deep well.

The inner 2" pipe is PVC (please take note Khonwan, I think it's PVC all the way with PVC glued unions/connectors) joined by a threaded union to a metal flange plate which then has an elbow then another union onto my PVC pipe distribution system leading to the filters. Tonight I disconnected the top union, pulled the whole thing up about half a meter to acheive an easy resting place. I then angled a watering can over the discharge nozzle such that the water spout was pointing back down the 6" jacket.

I then ran the pump, to fill the can and then shoot the water back down the jacket. Same result - the protection circuit kept tripping about every 5 mins, but the water was relatively clear. I repeated this about 10 times to see if the pipe would show any signs of filling - it didn't. I  also pulled the pump up and down a few times to see if I could "flush" the intake guard. - no real change.


There is no obvious sign of a check valve at the top end fittings on the pipe header.

The box of trickery is labelled as follows:

Sun motor submersible motorcontrol
Over current Protection
Pump = 1.0 hp

Any further clues  / ideas

cheers

[chownah]

The good thing about PVC is that if you haul out the pipe and cut it then it is really easy to just glue straight connectors on where you cut it when you reinstall it...and the connectors and glue are really cheap so its a cheap and easy process to pull your pump and then replace it....all you need are straight connectors, glue, and a brush to apply the glue...and maybe a rag to wipe off excess glue if your a neat freak.

Just whatever you do don't drop the pipe and pump.  When you reinstall the pump you might consider adding a tether so won't need to worry about dropping it next time....maybe you've got one already.

Chownah

Edited by chownah, 2007-03-28 20:46:41.

[RamdomChances]

My inner pipe is threaded metal, think it just depends. If it's plastic and snaps your going to have probs getting the pump out unless you have a wire attatched as well.

[Lickey]

I recently had my borehole cleaned out to a greater depth, from about 15mtrs to 23mtrs, I wanted to buy a 2hp sub for this, but the man in the local shop advised me against it, saying a 1hp would be adequate for my needs, he also told me that a 2hp pump would need a 2in riser, {inner pipe} normal/std size for 1hp is 1.5in pipe, unless the drilling crew fitted an adapter because they had only 2 in blue?? please check pipe size again, if a 1hp pump is pushing water up a 2in pipe 45 mtrs and then some, thats quite a weight of water, perhaps this is why the overload keeps cutting in? is it the right control box for the pump?is it the one that came with the pump?also all modern subs have a one way valve in the top of the pump, so trying to backflush it wont help much, muddy looking water is normal on start-up, this is the water in the liner pipe, mine clears in 2 mins as soon as new water comes into pipe.
Being a realtive newcomer to boreholes ive talked and listened to local people and admired the helpful replies ive had on here from experinced members on this site, perhaps Chownah can help with the mathmatics of a 1hp 2in pipe, 45 mtrs ect, cheers,,

[chownah]

Thinking that a larger diametre pipe holds a greater weight of water so it is more difficult for a pump is, unforturately, incorrect.  The things which create the work the pump must do is the PRESSURE AT THE PUMP DISCHARGE and the effort needed to get the water moving.  The three things that will affect this are the depth of the water, the flow resistence (friction betweent the water and the pipe), and the velocity of the water (how fast it is flowing).

Depth: In any body of still water (important to remember we are talking about water that is not moving for this depth discussion), whether its a lake, a bathtub, a bore, or a pipe, the deeper you go the greater the pressure.  It doesn't matter how wide the body of water is....it only depends on how deep you go in the water.  This means that the diametre of the pipe does not matter when considering the pressure at your pump for still water (the pump is off).

Flow resistence:  When water flows it "rubs" on the sides of the pipe and this creates friction....you can think of this as a force on the water that wants to keep it from moving...it is a force which acts counter to the flow and your pump has to work to overcome this force to keep the water moving......when you analyze the hydraulics you will see that this means that the pressure at the pump outlet is higher than for still water....this extra pressure gives the push that overcomes the resistence to flow.  If you want to pump the same number of litres per minute through two pipes then the smaller the diametre of the pipe the greater the flow resistence assuming that the pipes are equally smooth on the inside surface.  Also any bends will increase the flow resistence....I won't explain exactly why unless asked to do so as its probably just a distraction and not important why.

Velocity:  To get anything moving that is standing still requires effort.  The water in the bore hole is not moving and the pump makes it start moving up the pipe...this requires effort and the faster you want the water to move the more effort it will take.  Think about throwing a ball...it takes effort...the faster you through the ball the more effort it takes.....water works the same way even though its a liquid.  The faster the water goes in the pipe the more work the pump must do.  If you have two pipes with water flowing in both at the same number of litres per minute then the pipe with the smaller diametre will have its water flowing faster (as measured in metres per second) than it will in the larger pipe.   This means that it takes less effort for your pump to pump water in the larger pipe.


So..........using the smaller pipe will make your pump work harder because of flow resistence and higher velocity in the pipe.....and, while the larger pipe does indeed hold more water it actually decreases the work your pump must do.  

Chownah

[sinom]

chownah, on 2007-03-28 20:44:28, said:

The good thing about PVC is that if you haul out the pipe and cut it then it is really easy to just glue straight connectors on where you cut it when you reinstall it...and the connectors and glue are really cheap so its a cheap and easy process to pull your pump and then replace it....all you need are straight connectors, glue, and a brush to apply the glue...and maybe a rag to wipe off excess glue if your a neat freak.

Just whatever you do don't drop the pipe and pump. When you reinstall the pump you might consider adding a tether so won't need to worry about dropping it next time....maybe you've got one already.

Chownah

Chownah - agree with the PVC bit not too difficult a job. The tether appears to be a green nylon rope that disappears down the jacket with the pump cable. It looks like I'm going to have  to pull the whole thing up. !!

RamdomChances, on 2007-03-28 21:55:49, said:

My inner pipe is threaded metal, think it just depends. If it's plastic and snaps your going to have probs getting the pump out unless you have a wire attatched as well.

RandomChances - I think I prefer the PVC pipe, with respect to possible rusting but do pay heed to the point of broken pipe !!

Lickey, on 2007-03-29 01:59:31, said:

I recently had my borehole cleaned out to a greater depth, from about 15mtrs to 23mtrs, I wanted to buy a 2hp sub for this, but the man in the local shop advised me against it, saying a 1hp would be adequate for my needs, he also told me that a 2hp pump would need a 2in riser, {inner pipe} normal/std size for 1hp is 1.5in pipe, unless the drilling crew fitted an adapter because they had only 2 in blue?? please check pipe size again, if a 1hp pump is pushing water up a 2in pipe 45 mtrs and then some, thats quite a weight of water, perhaps this is why the overload keeps cutting in? is it the right control box for the pump?is it the one that came with the pump?also all modern subs have a one way valve in the top of the pump, so trying to backflush it wont help much, muddy looking water is normal on start-up, this is the water in the liner pipe, mine clears in 2 mins as soon as new water comes into pipe.
Being a realtive newcomer to boreholes ive talked and listened to local people and admired the helpful replies ive had on here from experinced members on this site, perhaps Chownah can help with the mathmatics of a 1hp 2in pipe, 45 mtrs ect, cheers,,

Lickey - good info. I should have paid more atention to detail when the put the pump in the ground!! It could well be a 1.5" pipe, I didn't actually read the writing on the pipe I just assumed it was 2". I will check further. The control box came with the pump and was fitted by the contractor - I assume it's the correct one. You are also correct in that the water clears pretty quicly when it starts to run. My contractor assured me the 1hp pump was amn enough for the job. As stated above I think my only remaining option is to pull the pump and have a look see.

It's so frustrating that I appear to have a good supply of water down there but can't get the stuff to the surface

thanks for  the suggestions and advice so far

[RamdomChances]

Quote

RandomChances - I think I prefer the PVC pipe, with respect to possible rusting but do pay heed to the point of broken pipe !!

It is galvanized pipe. I don't think it really matters that much as long as you have some way to pull the pump up if needed.

[chownah]

If you should decide to go with galvanized pipe be aware that galvanized pipe is heavy and 45 metres of it will weigh alot...especially if you use 1.5 inch pipe!!!!!...or larger!!!!!.....so you will need to be sure that whatever holds the pipe up (quite often the liner) is adequate.....a pvc boreliner might not be strong enough...I don't know.

And by the way....I'm sort of surprised that a 1.5" pipe is used with a one horse power pump.  All the one horse pumps I've seen have 1" outlets and are recommended for use with 1" pipe.....but then I have not seen all the pumps in the world either.

[Gary A]

sinom, on 2007-03-28 19:34:54, said:

Gary A, on 2007-03-28 11:11:13, said:

sinom, on 2007-03-28 09:32:15, said:

Chaps et al

very interesting thread.

I have recently installed a 45 m well at my house in Banglamung to service house and swimming pool and garden. My city water bill normally runs to about 2500 THB per month so the economics of installing a borehole system for 80,000 THB are fairly self evident.

The company I used performed a fairly professional job (for Thailand), installed a 6" jacket, with a 2" pipe insert with the pump attached. I can't remember the spec for the pump and it is now sunk down 45m. !! The pump was supplied with a box of tricks which includes a thermal overload circuit.

The water I get was tested and found to contain an excessive amount of particulates and slightly acidic.

So I've installed an active carbon filter system with particulate removal added. Tested the system and it's great ! I get perfectly clean water that's good for everything I need.

But........ here comes the problem ........... The pump runs inititially for about 5 minutes and then trips repeatedly on what I think is thermal overload.

If I leave it for a few minutes, perform a reset to the relay I can restart and get another 5 minutes. This is very frustrating.

The water coming of is fairly brown in colour and creates a small amount of mud sediment in my upstream screen filter. I was concerned that during construction some dirt may have gone back down the outer jacket and be fouling the pump. I can't fully remove the pump to inspect it without cutting up the 2" inner pipe on removal. So I removed it about two meters up and down to see what would happen. The result was that the pump ran for what seemed to be a little longer then tripped out again.

Does the collective experience on this thread have any advice on this?. My concern now is that the pump is under powered and stuggling to pump against a 45m head of water containing a degree of sludge and I will have to pull the whole thing out to inspect it, cutting up the pipe as I go, then possibly replace the pump, but not know if this is correct until the whole thing is back in place and I try again.

Thanks in advance

You probably have a check valve (one way valve) installed just outside of the top of the casing. I would take the check valve out and allow the water in the pipe to backwash back down through the pump. Maybe even force more water down the pipe. That should clear any debris from the screen on the pump. To pull the pump a meter or so higher in the casing would also be a good idea. You should have some information regarding the pump capacity. Check to see if it is rated to push water the 45 meters. That is a deep well.

The inner 2" pipe is PVC (please take note Khonwan, I think it's PVC all the way with PVC glued unions/connectors) joined by a threaded union to a metal flange plate which then has an elbow then another union onto my PVC pipe distribution system leading to the filters. Tonight I disconnected the top union, pulled the whole thing up about half a meter to acheive an easy resting place. I then angled a watering can over the discharge nozzle such that the water spout was pointing back down the 6" jacket.

I then ran the pump, to fill the can and then shoot the water back down the jacket. Same result - the protection circuit kept tripping about every 5 mins, but the water was relatively clear. I repeated this about 10 times to see if the pipe would show any signs of filling - it didn't. I  also pulled the pump up and down a few times to see if I could "flush" the intake guard. - no real change.


There is no obvious sign of a check valve at the top end fittings on the pipe header.

The box of trickery is labelled as follows:

Sun motor submersible motorcontrol
Over current Protection
Pump = 1.0 hp

Any further clues  / ideas

cheers

Running the pump and putting the water back down the casing will not back flush the pump. You have to have the power to the pump shut off. The smaller pipe (outlet) coming out of the casing needs to be disconnected and if there is no check valve at the pump, the water will flow back down the outlet pipe through the pump. If the water in the pipe coming out of the pump does not drain down that means the check valve is on the pump and you will not be able to back flush from the top of the casing. You will then have to pull the pump to inspect it. A good installation will have a stainless cable attached to the pump and it will be attached to the top of the casing. Sometimes they save a few baht and use plastic or nylon rope. Unfortunately it usually works better to have the check valve on the pump itself. That means you can't flush the pump without pulling it out. Sometimes they call it a foot valve because it is at the bottom of the well. The cable or rope is a safety measure in case the pipe breaks or you accidently drop the pump. The power cable is NOT a good way to pull the pump out.