Hello ,

Let me explain the scenario. I live in a building. We have a water pipe supplying water from the city mains running parallel to my building. This horizontal water pipe is shared between my neighbour and me. We both have water pumps that suck water and fill our overhead storage tanks.



http://img36.imageshack.us/img36/4835/pumpdiagram.jpg (http://img36.imageshack.us/i/pumpdiagram.jpg/)


Please refer to the key in the diagram to understand the shapes .

If the figure does not load, please click : Imageshack - pumpdiagram (http://img36.imageshack.us/i/pumpdiagram.jpg/)


I have a check valve just about half an inch from the beginning of the vertical pipe. Off late, whenever I start my pump,after say a gap of 20 hours, I get a very shrill sound from the pump for 2-4 seconds and I do not get any water. If I leave the pump on after this sound, about 4-7 minutes later, I will get a perfectly normal flow of water.

Alternatively, I can open the priming tap( which is connected to the suction line of the pump) and pour some water in the suction line, a shrill sound comes once again lasting about 2-4 seconds and then I get the normal flow of water.

Another thing, I've noticed is if we switch off the pump after its run for 30-45 minutes and after the water started flowing, then restart it after 15- 30-45-60 minutes ( never tried beyond 60 minutes), I would never have to do any of the things I have mentioned above. The water would just flow normally.

We have not had any problem with this setup all these years, however this problem started the day my neighbour extended the main pipe & took a separate connection from the mains till his house. Earlier we had a mutual understanding where one pump ( placed in my house ) would supply water to both houses.

Now since we have separate pumps, we start pumps one after the other, never together.

When my neighbour did this separation I saw that I had a leaking check valve which was leaking like say 30 drops a minute or less. I did not bother changing it that day.

I did another test because I felt that even if it was leaking, since it was connected so close to the source it would not matter. I filled the suction line completely using the priming tap near the pump and then monitored it for 12 hours, I did not notice any noticeable drop in the level of water. Can this method be used to check for a leak in a check valve ?

I still have not replaced the check valve.

I feel it's a air leak somewhere, but I cannot figure it out.

I hope I have explained the problem well enough and I hope we can find a solution to this daily priming activity.

Thanking you

Danny

If you are connected to a water main which is, I presume, pressurized, then why do you need pumps to pump water into holding tanks? Why not just use the city water? AND, I would think that priming your pump would not be an issue since the suction line is actually tied in to a pressurized water supply. So plainly I am missing something here.

If you are connected to a water main which is, I presume, pressurized, then why do you need pumps to pump water into holding tanks? Why not just use the city water? AND, I would think that priming your pump would not be an issue since the suction line is actually tied in to a pressurized water supply. So plainly I am missing something here.

Hi, well we live on the second floor and the water pressure is no longer sufficient to climb two floors naturally. Hence, the need for a pump.

Jlisenbe said,
I would think that priming your pump would not be an issue since the suction line is actually tied in to a pressurized water supply. So plainly I am missing something here. and so am I. How could you lose prime when you have pressurized water supplying the impeller cage? I want to know! Tom

Jlisenbe said, and so am I. How could you lose prime when you have pressurized water supplying the impeller cage? I wanna know! Tom


Its not pressurized, it flows naturally.

Is you pump on the second floor? If so, I would say that you have a leaking check valve. One that leaks when you neighbors pump is run. You need a positive stop check valve. Obviously the noise is the pump running with out any water in it.

Yes my pump is on the second floor . I do have a leaking check valve.

However, I did this


I did another test because I felt that even if it was leaking, since it was connected so close to the source it would not matter. I filled the suction line completely using the priming tap near the pump and then monitored it for 12 hours, I did not notice any noticeable drop in the level of water. Can this method be used to check for a leak in a check valve ?


Secondly, my neighbour starts his pump after me on a daily basis. If I were to start mine after he switched his off, I would face no such trouble .

However, if I let some hours pass, I would face the trouble.


BTW, how do we edit here ? I can't seem to find an edit button.

flows naturally. Is this a artesian self flowing well?
Make me a new drawing showing where the control box's located and explain why there isn't a check valve on the suction pipe to prevent losing prime.
Also, when prime a pump we fill the inpeller cage from the top not the discharge line.
It seems to me that by loading up the discharge line it fills at the tap and you leave the impeller cage empty.
I filled the suction line completely using the priming tap near the pump Not from the way your drawing shows. The way you show you can only fill the discharge line and then only up to the primer tap.
I'm with Jlisenbe on this. Too many unanswered questions and too much that doesn't make sense. The edit button's next to the quote button at the bottom.
Let's have better explainations. Thanks, Tom

Being a new member you may not have an edit button. You will after a few post.
Did your neighbor install a check valve on his pump system?

Is this a artesian self flowing well?
Make me a new drawing showing where the control box's located and explain why there isn't a check valve on the suction pipe to prevent losing prime.
Also, when prime a pump we fill the inpeller cage from the top not the discharge line.
it seems to me that by loading up the discharge line it fills at the tap and you leave the impeller cage empty.
I'm with Jlisenbe on this. Too many unanswered questions and too much that doesn't make sense.
Let's have better explainations. Thanks, Tom


Lets start from scratch. I've made the diagram contain labels now, I feel that may have made it difficult to understand it. P

http://img142.imageshack.us/img142/4835/pumpdiagram.jpg (http://img142.imageshack.us/i/pumpdiagram.jpg/)


1. We get our normal water supply for doing our daily chores through the city's main pipes for a few hours every day. These pipes come from the main purification centres of the city, supplying water to most of the buildings in the locality. We do not have wells .

2. To the city's main's we connect our pipe which then runs horizontally parallel to our building. In my diagram above this is the one with the arrow pointing in the rightward direction.

3. To that pipe we connect a vertical pipe coming to our house. The square box at the base is the check valve ( forgive me , I cannot draw diagrams well, so I used shapes. )

4 I don't understand what you mean by control box, but, if you mean how the pump starts and stops we have different ways for that but they do not connect to the water pipes in any way so I am not going to explain that. For the moment, lets consider I start the pump manually and switch it off manually.

5. My Priming tap is connected on the suction line, the same line to which the check valve is connected. We do not fill the discharge line, we prime the pump using the priming tap which fills the impeller cage of the pump.

6. The delivery from the pump goes to the overhead tanks for storage & the overhead tanks are connected to the taps.


Thank you.

Being a new member you may not have an edit button. You will after a few post.
Did your neighbor install a check valve on his pump system?

Yes my neighbour does have a checkvalve on his suction line too.

In your situation, why not just use a booster pump? That is what they are designed for. I am assuming you have to manually turn your pump on to fill the holding tank, then manually turn it off when it's full. Either that or you have a float switch in the tank, but your description doesn't sound that way. At any rate, booster pumps are designed for what at least sounds like your situation.

Davey Booster System with Torrium- +30 psi 14 gpm - FreshWaterSystems.com (http://www.freshwatersystems.com/p-3609-davey-booster-system-with-torrium-30-psi-14-gpm.aspx)

It is difficult to connect a booster pump outside the house, due to regulations. Hence, we need pumps to suck and then throw.

We do have mechanisms to start the pump and switch it off when the tank reaches its overflow level,thereby completely automating the process, however we cannot use this mechanism right now, because, the pump needs manual intervention (priming) each time it starts after a long time interval .

This is why I am so desperate to solve this problem.

Thank you for your time .

Thanks Danny, I should have asked. Are you in the UK?
Things are much clearer now. I think we all agree that the check valve must be replaced and I would replace with a sprring loaded one.
, Everything was just peachy until your neighbor installed his own pump up stream from you. Even with a leaky check valve you held prime until your neighbors pump kicked on. This lowered the pressure in the main and set up a suction that sucked the prime right out of your pump. Does that work for you?
It all goes back to your check valve. Does it mount vertical or horizontal? Replace with a spring loaded check valve and let me know how that works. Good luck, Tom

That does make sense. The thing I just can't get over is this. Even if it's the neighbor's pump cause prime to be lost, why doesn't the municipal water line's pressure rather easily restore prime? Oh well. Perhaps there are some things we're just not meant to understand. I do like SB's solution.

, Everything was just peachy until your neighbor installed his own pump up stream from you. Even with a leaky check valve you held prime until your neighbors pump kicked on. This lowered the pressure in the main and set up a suction that sucked the prime right outta your pump. Does that work for you?
It all goes back to your check valve. Does it mount vertical or horizontal? Replace with a spring loaded check valve and let me know how that works. Good luck, Tom

Im located in India. Presently I have a spring loaded check valve mounted vertical. I am a little confused about the lines you mentioned above so I have tried to explain something, are we talking about the same thing ?


I did this way to check if my neighbours setup was affecting me.

Lets assume with an example :

1. I started my pump at say 8pm this evening, primed it, it started sucking water. Switched it off at 8.30 pm and allowed my neighbour to start his.

2. He switched his off at 9 pm and I started mine again. At this stage I would not need to prime the pump again.

3. Now I switch it off . Thereafter my neighbour too does not start his pump.

4. I start it at again next day at 8pm again , I need to prime it.


Thanks for all the help.


That does make sense. The thing I just can't get over is this. Even if it's the neighbor's pump cause prime to be lost, why doesn't the municipal water line's pressure rather easily restore prime? Oh well. Perhaps there are some things we're just not meant to understand. I do like SB's solution.

Yes, this is exactly what I was wondering so I tried it out once patiently I started the pump and did not prime it .

The municipal line eventually did prime my pump but that was a good 5-10 minutes of letting the pump run dry before it started sucking without any manual intervention at all.

I don't like the idea of letting it run for 5-10 minutes dry and hence I prime it.

I think I came up with about the only scenario that explains everything. Your check valve would let you retain prime if it wasn't faulty and your neighbors pump wouldn't create a vacuum if the main were pressured. Bottom line! Your check valve's there to prevent you from losing prime. If it were working correctly you wouldn't be losing it. Replace the check valve and see if things don't get better. Good luck, Tom

Amen! Being in India, and not trying to look down my nose at India since I know people from there and they are terrific people, but I can imagine a municipal line with little to no pressure depending on the time of day and demand.

I think I came up with about the only scenario that explains everthing. Your check valve would let you retain prime if it wasn't faulty and your neighbors pump wouldn't create a vacuum if the main were pressured. Bottom line! Your check valve's there to prevent you from loosing prime. If it were working correctly you wouldn't be loosing it. Replace the check valve and see if things don't get better. Good luck, Tom

Thanks for replying.

I did understand what you were saying however, I thought, you may have been meaning something else with a line, which is why I explained something else.

Will have a look at that check valve.

Thanks for the help.


Amen! Being in India, and not trying to look down my nose at India since I know people from there and they are terrific people, but I can imagine a municipal line with little to no pressure depending on the time of day and demand.

Its more of the demand factor and the aging of pipes that causes most of these problems.


Thanks for the help.