Jet Pumps Chapter 3.

[carlyai]

After being persuaded that jet pumps do work, I installed a couple on our bores.
 
Both had recently decided to stop pumping, and on inspection, it's been the same old problem that happens once or twice ever couple of years: loss of water head. With no real clue to the reason, I replaced the valve at the inlet to the pump head.
Thought was that if this valve stays open, all the water drains out of the pump and it can't prime.
So replaced the back pump bore valve, and no worries all pumping normal.
Replaced the front bore pump valve, and the pump works normally for a day, then all the prime water drains out and the pump won't work.
No worries, rock the pump pipes into the bore up and down, and seem to get a water seal and head, and the pump works normally, until the next day, all the head water has drained out the pipe.
So I'm now in the process of replacing the head unit. Can't think of why it would be this unit (except for the venturi hole in the head unit).
 
Any thoughts?
 

 
This is the head unit I'm going to replace. Already replaced the bottom valve in the yellow cover.
 

 

 
I have different pipes other than specified on the name plate: 20 mm and 35 mm. Must have been what the pump/tractor shop told me to use.
 

 
The lift is less than 10 m.
 
Now my brother in law has a similar jet pump, and the way he has it connected can't possibly work, but he has no trouble (well he doesn't seem to when I'm looking).
 

 
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EDIT
The only thing that could be different between my brother in laws set up and mine, is that his venturi is near the pump where as mine is at the end of the pipes.

[bankruatsteve]

I'm no expert, so just to say that the jet pumps I have seen (including mine) have two pipes going down the bore hole with the venturi connected to the ends (at the bottom of the bore).  While my pump is self priming, there is usually a cap for that purpose.  

[carlyai]

I'm no expert, so just to say that the jet pumps I have seen (including mine) have two pipes going down the bore hole with the venturi connected to the ends (at the bottom of the bore).  While my pump is self priming, there is usually a cap for that purpose.  

Hi and thanks.
Yes, that's what I mean about the bils pump...it can't possibly work but it does and he doesn't seem to have my troubles. Maybe more visits to the WAT required?

Mine also has a capped hole for water to enter to prime the pump. The primer water has to fill up all the length of pipe, and is held there by the spring loaded valve at the bottom of the pipe. With the valve closed the water primes the pump, but leaks out somewhere so it won't prime the next day.
I can only suspect that ...don't really know [emoji848]

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[Artisi]

Hard to really comment without actually seeing the installation and more detail, but - is it the valve at the venturi inlet  leaking and draining the pump system (your first photo).

The set up at your bother-in-laws is a valid set-up, used for self-priming and if there is less than about 8 metre vertical lift from the well - (shallow well)

Do you know what the water level (your well) is when actually pumping - if over 8 metre it is a deep well. 

 

 

Edited March 27, 2018 by Artisi
added terminology

[kamalabob2]

Many Thai Visa forum members have posted good replies to this well topic. The OP might gain better well water success if he visits the #1 water pump dealer in his Province. By and large it will be the dealer who sells Mitsubishi Super Pumps. He will 100% gain a better well experience if he tosses the 55 baht plastic foot valve and installs a brass valve made by TP Valve also know as ANA valve in Thailand. 

http://www.tpvalve.com/thai/valve03_3.htm

 

Often Thai family pick the "cheapest" part, and are unclear on long term success of buying a better grade of water pump parts. Some tractor stores might not actually have stock of brass valves.  The blue plastic valve would not be my choice for a well. 

Edited March 27, 2018 by kamalabob2

[Artisi]

The setup for the BIL pump, ejector (eductor) is at the pump inlet.

 

Edited March 27, 2018 by Artisi

[Artisi]

2 minutes ago, kamalabob2 said:

Many Thai Visa forum members have posted good replies to this well topic. The OP might gain better well water success if he visits the #1 water pump dealer in his Province. By and large it will be the dealer who sells Mitsubishi Super Pumps. He will 100% gain a better well experience if he tosses the 55 baht plastic foot valve and installs a brass valve made by TP Valve also know as ANA valve in Thailand. 

http://www.tpvalve.com/thai/valve03_3.htm

 

Often Thai family pick the "cheapest" part, and are unclear on long term success of buying a better grade of water pump parts. Some tractor stores might not actually have stock of brass valves.  The blue plastic valve would not be my choice for a well. 

In the OP post, he shows a brass NRV at the eductor inlet.

[farmerjo]

If its not holding water,you have a leak in either a pipe,pipe join or foot valve not closing properly.

It may show up now with the water table dropping at this time of year.

[carlyai]

Hi Artisi, and thanks for the reply. Several years ago I think it was you who convinced me jet pumps work.

 

Replies to your questions:

 

'... is it the valve at the venturi inlet  leaking and draining the pump system (your first photo).'

 

Yes, that's what I thought, so I replaced the valve and the water still leaks out of the pipe.

 

 

'The set up at your bother-in-laws is a valid set-up, used for self-priming and if there is less than about 8 metre vertical lift from the well - (shallow well)'

 

Yes, I had come to that conclusion when I took a picture of it today.

 

At the moment the water table here is high, due to all the rain we've had. It is above 8 m. So the pump lift is less than 8 m at the moment.

 

I can't remember, but I must have put this pump in in the dry season with the water level lower. I think I put the pipe ends 3 m into the water aquifer.

So at the moment I have a deep well setup when I should have a shallow well set up.

Could this cause the trouble I'm having?

Easy to change to a shallow well set up.

 

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EDIT

 

The water table is about 6.5 m down or 6.5 m of lift required at the moment.

[carlyai]

If its not holding water,you have a leak in either a pipe,pipe join or foot valve not closing properly.
It may show up now with the water table dropping at this time of year.

Thanks for your reply. I have just visually checked the pipe joins. Need to check them properly as we could have ruptured one when we replaced the foot valve.

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[farmerjo]

Did you have a lengthy power cut coinciding with the same time it stopped working? 

[Artisi]

49 minutes ago, carlyai said:

Hi Artisi, and thanks for the reply. Several years ago I think it was you who convinced me jet pumps work.

 

Replies to your questions:

 

'... is it the valve at the venturi inlet  leaking and draining the pump system (your first photo).'

 

Yes, that's what I thought, so I replaced the valve and the water still leaks out of the pipe.

 

 

'The set up at your bother-in-laws is a valid set-up, used for self-priming and if there is less than about 8 metre vertical lift from the well - (shallow well)'

 

Yes, I had come to that conclusion when I took a picture of it today.

 

At the moment the water table here is high, due to all the rain we've had. It is above 8 m. So the pump lift is less than 8 m at the moment.

 

I can't remember, but I must have put this pump in in the dry season with the water level lower. I think I put the pipe ends 3 m into the water aquifer.

So at the moment I have a deep well setup when I should have a shallow well set up.

Could this cause the trouble I'm having?

Easy to change to a shallow well set up.

 

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EDIT

 

The water table is about 6.5 m down or 6.5 m of lift required at the moment.

No problem if the "Jet" is deeper into the aquifer, if the aquifer varies throughout the year - leave it as deep well.

You need to check for leaks, these systems are simple - but you have to keep the water in the system - if it leaks - it doesn't work - as you are experiencing. 

 

Edit. any sign of sand etc in the pumped water - if yes - could be holding the check valve slightly open. 

Edited March 27, 2018 by Artisi

[carlyai]

Did you have a lengthy power cut coinciding with the same time it stopped working? 

No I don't think so. We did have a 2 hr power fail, but can't tie that in with the time the pumps stopped.

You gotta theory with power fails and pumps?

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[carlyai]

No problem if the "Jet" is deeper into the aquifer, if the aquifer varies throughout the year - leave it as deep well.
You need to check for leaks, these systems are simple - but you have to keep the water in the system - if it leaks - it doesn't work - as you are experiencing. 
 
Edit. any sign of sand etc in the pumped water - if yes - could be holding the check valve slightly open. 

No sign of sand in the valve.

Farmerjo said to check the pipe joints, which I haven't done 100%.

I've got one of the strongest men in the world across the road who helps me. He in fact listens and does what I ask, but a bit rough. So he could have fractured the pipes as he swung from the fence and passion fruit terrace pulling up the pump pipes.

So to plan A:

At the moment, as my back aquifer pump and the BILs pump are both shallow water, I'm going to go for shallow water jet pump. (This will also make the whole village happy as I'm eventually doing it the Thai way [emoji3]).
It will also mean only one pipe into the aquifer, and less chance of breakage when 'strong man' (that's what the locals call him) reinstates the pipe in the aquifer.

I'll buy the shallow water kit and high spec. 30 cm pipe and use all new pipe.

What do you think?

Tomorrow's day planned.



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[Artisi]

8 minutes ago, carlyai said:

No sign of sand in the valve.

Farmerjo said to check the pipe joints, which I haven't done 100%.

I've got one of the strongest men in the world across the road who helps me. He in fact listens and does what I ask, but a bit rough. So he could have fractured the pipes as he swung from the fence and passion fruit terrace pulling up the pump pipes.

So to plan A:

At the moment, as my back aquifer pump and the BILs pump are both shallow water, I'm going to go for shallow water jet pump. (This will also make the whole village happy as I'm eventually doing it the Thai way ).
It will also mean only one pipe into the aquifer, and less chance of breakage when 'strong man' (that's what the locals call him) reinstates the pipe in the aquifer.

I'll buy the shallow water kit and high spec. 30 cm pipe and use all new pipe.

What do you think?

Tomorrow's day planned.



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Any pipe joints , roughen the surfaces before applying the pipe glue, fully insert and if possible give a 1/ 4 to 1/2 turn.

For me I would stick with the deep set-up.

[carlyai]

Any pipe joints , roughen the surfaces before applying the pipe glue, fully insert and if possible give a 1/ 4 to 1/2 turn.
For me I would stick with the deep set-up.

Hi thanks again. I've filled the pipes with water and there are no leaks in the pipes or joints. I didn't pressurise the pipes during the test.
So my aim is to make it all simpler. The jet near the pump and only one pipe into the aquifer and the footer valve.

I did notice that sometimes before with the dual pipes and jet near the footer valve, that turning off the water by shutting the tap of seemed to cause waves in the pipe and the pump would turn on and off with the water surges, then at the end all the water had drained out through the footer valve.

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[bankruatsteve]

5 minutes ago, carlyai said:

I did notice that sometimes before with the dual pipes and jet near the footer valve, that turning off the water by shutting the tap of seemed to cause waves in the pipe and the pump would turn on and off with the water surges, then at the end all the water had drained out through the footer valve.
 

 

But, isn't the "footer valve" suppose to be a NRV?  Also, and this may not relate one bit... with my pump I have a stop valve at the pump output and I find it needs to be about 3/4 open (not more) for the pump to come up to pressure and run normal.  Don't know why but that's my pump.

[carlyai]

 
But, isn't the "footer valve" suppose to be a NRV?  Also, and this may not relate one bit... with my pump I have a stop valve at the pump output and I find it needs to be about 3/4 open (not more) for the pump to come up to pressure and run normal.  Don't know why but that's my pump.

Hi, the footer valve is spring loaded, and should be a NRV. So that's why it's got me beat as to why the primer water head in the pipe between the NRV and the pump inlet leaks away. It would indicate the valve is staying open. But when inspected there doesn't seem to be any sand or sentient around the valve or pipe end and it seems to have a good seal.
Anyway, when it stops raining, I'm going to change for the shallow well set up.

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[carlyai]

In the process of changing the pump set up to shallow water type, I undid the other 2 water outlets on the tank and there was lots of very fine sand at the bottom of the tank. Couldn't see it in the tank from the outlet I was using.

So now I think everything was working normally, and the footer valve was sticking open due to the fine sand, but when I pulled the pipes up, the sand washed out...I couldn't see any debris in the footer valve.

With the new set up I've cut the pipe off at 7.5m as the water table is at 5.66m. Maybe I had the pipe too near the bottom of the aquifer before.

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[Artisi]

1 hour ago, carlyai said:

In the process of changing the pump set up to shallow water type, I undid the other 2 water outlets on the tank and there was lots of very fine sand at the bottom of the tank. Couldn't see it in the tank from the outlet I was using.

So now I think everything was working normally, and the footer valve was sticking open due to the fine sand, but when I pulled the pipes up, the sand washed out...I couldn't see any debris in the footer valve.

With the new set up I've cut the pipe off at 7.5m as the water table is at 5.66m. Maybe I had the pipe too near the bottom of the aquifer before.

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Keep us updated.

[carlyai]

Update:

Picture of the fine sand and system.

Ready for a trial tomorrow.

This time I put in a flexible hose from the pump outlet to the underground water pipe. This time if the footer valve gets stuck with sand it will be easier to shake the pipes up and down to wash out the sand in the footer valve.

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