water botle, loosing preseure and not getting water through?

[john_374325148]

Hi all, is there anyone who could give me any advice pleases?

Having just got back from our last holiday of this year, ready for the van to be laid up ready for the winter,

I,v a plastic 25 L water container with a tap on it, which i have on a clear half inch tube which in turn conects into the double inlet / outlet socket.

In my van i,v got a floor mounting self priming foot operated diaphragm pump, now before getting water up through the tap no problem, it came through ok, but whilst on this holiday, as you pump the pump the water container, plastic water containner, was being sucked in and very little water was comming out of the tap, i had to undo the water bottle cap to release the air out, it would work for a bit but then going back to a small trickle of water from out of the tap,inside the van.

This was very frutrating, in the end i undone the water botle and placed it on the table in the awning and held the kettle ect under it to get water .

Now is there something i can do to cure this problem, replace the foot pump,ect, is this a common problem with these foot pumps or what, any ideas please, thanks john.

 

[ProfJohnL]

Hello John,

I think you have found a clue to the problem your self, but perhapse have not understood it.

When you are pump water out of your container you are actually causing a vacuum in the tank. As the vacuum gets stronger the more water you try to pump out, and the consequence is the flow of water gets smaller, and evetiually it will stop when the pump cannot overcome the vacuum.

The tank needs to allow air into the top so a vacuum never forms. Release the lid just a bit to allow air to replace the water you are pumping out.

 

[john_374325148]

Hello John,

I think you have found a clue to the problem your self, but perhapse have not understood it.

When you are pump water out of your container you are actually causing a vacuum in the tank. As the vacuum gets stronger the more water you try to pump out, and the consequence is the flow of water gets smaller, and evetiually it will stop when the pump cannot overcome the vacuum.

The tank needs to allow air into the top so a vacuum never forms. Release the lid just a bit to allow air to replace the water you are pumping out.

Thanks john L, I ,v pick up from my local carvan shop something which hopefuly will help, ...

Its long tube which will go to the bottom of the water comtainer, which has at the top a rubber seal cap wich goes over the threaded part of the water container, on the tube the other end a half inch hose which goes onto the inlet on the van.

Where the rubber seal cap theres a slight gap, which i hope will releas the air as im pummping the water through.

Hopefullly this will give constant water flow withoutthe vacume being caused through pumping, again many thanks for your advice and will give this s go, john w.