SteveB wrote:
I want to lift water about 20 feet from my truck to the storage tank on the
second floor of my cabin.

I used to be a commercial diver, and have used many types of "airlifts."
This is a device where a suction is created by venturi-ing air into a line
in the direction you want it to flow. In real underwater conditions, the
air expands as it rises, increasing the suction power. It really sucks up
whatever is in front of the nozzle.

I was playing with the idea of buying a pump that I could pump water from my
truck tank up to the storage tank of the cabin. (This is just for winter
use. In the warm months, there is a water system.) I am running into the
problem that a lot of them just don't have a lot of head pressure. And they
cost a lot. And they require special plumbing connectors. A small
compressor would not have to put out a lot of air to lift the water in a
1/2" line and get it to rise up. The bubbles will push the water up and
rise automatically.

Anyone else ever done this? Venturiing is a good way to make suction
devices for all manner of applications, and they are really safe because
they just use air or water.

Steve

The venturi effect may have a very slight effect on the air lift tube,
but mostly it is the water pressure itself that lifts the column. By
putting air in the column you're reducing the pressure inside, causing
the water to rise. You need depth to make it work.

I'd look for a cheap water pump. You don't need much pressure for a 20
foot head, which is just about 10 psi. Garden hose connections should
do it, although they're probably in violation of some health or
building code.

John Martin