Finally I think I got it !

[wizkycho]

Hi all !

this is mod. of Gravitator's idea

green enbodyment is ponton-bridgelike heavy body, with characteristic that overall is lower density material than water
so it floats. call it moveable part MP

1. air presassure created by gravity on MP makes water climb and fills container.
2. valve on MP opens (in and out valves on container are now closed)
3. since MP has lower density than water it is pushed upwards by boyancy.

totaly clean, can be used to generate electricity, hydropower plants (but without devastating ekosystem)...

mechanically not so complex to produce -  (maybe to us - low/no money-time-labspace-equipment guys)
If someone who is genearting energy/money crysis and polution, would really give a fuck, building this is easy as cake.
Of course we would give them and did even better solutions.

Wiz

[sushimoto]

Hi,
Nice and easy to follow system.
Its an interesting evolution since your first post on this

I'll wait for some Archimedes to do some math and perhaps it will soon to be build.

Thanks,
sushimoto

PS: Your Topic "Finally I think I got it !" is a perfect signature for this OU-forum. 

[wattsup]

V1 should be at the bottom of the riser tube.

[sushimoto]

.. so there is less height to pump? Nope, it needs the weight from the topmost position the piston.

Dimensioning for math?

Edit:
Since this is an simple system with a few parameters only, and assuming that the liquid is water,
it can be calculated easily. Here are the basics: http://www.lhup.edu/~dsimanek/museum/themes/buoyant.htm
Maybe, somebody can withdraw some conservation laws, but friction and viscosity is the devil here.
The pressure apliied to the sealing-ring is enormous.

[wattsup]

No, so the water in the tube does not have a tendency to fall back into the tank.