In this case, the water comes from a source located higher than the pump. (This is important.) As this inlet water descends from the source, it increases in speed and exits through the drain valve. However, this moving water causes the non-return valve A to close, which prevents the water from coming out. But since the water moves through a closed valve, it is redirected at the top past the other check valve, B, and causes the air space to compress. Once the air is compressed, the water stops flowing and valve B closes. Once this valve is closed, the compressed air acts like a spring to push the trapped water up the outlet pipe. Then the whole process begins again.
It’s quite complicated; it’s hard to adjust the values to get the thing to work properly. So I’m not going to build a ram pump, but if you want to try, here’s a nice video that shows one that really works. (Good luck.)
In the meantime, let me highlight the key aspects of this pump. First, the pump is lower than the water source, but the flow is higher than the water source. It may sound weird, but that’s the way it is. Second, each time the water is pumped to a higher level, some of the water is ejected from the pump—this is waste water.
OK, back to the TikTok video. Could it be a ram pump? Remember that you need three levels for this type of pump: the outlet is at the highest level, the water source is in the middle, and finally the pump is at the bottom. If you don’t have these three levels, you don’t have a ram pump.
In the diagram I drew above, based on this video, the person is pumping water from a river, which appears to be the source of the water. So it can’t be a ram pump, because the water can’t come out of the river directly. Remember that the pump must be at a lower level as the source. And in this case, the source, not the pump, is the lowest level in the system.
The other thing to look for is sewage. In a true ram pump, there should be additional water spurting from the lower level. Without it, you don’t have a ram pump. And in the video, there is no sewage visible.
Well, then how could that work? Who knows. Maybe it’s just an illusion. Perhaps there is an electric pump submerged in the river and connected to the pipe. I tried to message the person who posted the video and got no response.
The big question is, does a ram pump create free energy? This certainly seems to be the case, as you are moving the water to a higher place. This would increase its gravitational potential energy, instead of moving it down and decreasing its potential.
But that’s not really what’s happening. Imagine we have a working ram pump. Suppose I start with 20 kilograms of water at the source. There is a pipe that goes down 1 meter to a pump. After that, part of the water (say 10 kilograms) is pumped up to a height of 1 meter above the original source, so that it increase in gravitational potential energy. This means that only 10 kg of water was ejected as waste at the pump – but since it went down it has had a decrease in gravitational potential. Overall, with 10 kg going down 1 meter and 10 kg going up 1 meter, the net energy change is… zero. The pump “pays” for the higher energy water at the outlet by letting the water flow to a lower point.
Of course, in this example, the pump would be 100% efficient, and that never happens. Energy is lost in the ejected water and in the friction between the water and the pipe.
And that brings us to one last problem: even if you had an incredibly efficient generator powered by the water falling from the ram pump, it always would not give you free energy. Since some of the water has to be ejected at the lower end, the water source would eventually dry up. That would mean you have to use energy to lift more water to add to your source. Oh no! Now you have just lost your free energy program.
Ultimately, siphon and piston pumps move water without any external power input, but you don’t get more energy that you started out with. However, you can get water wherever you want. And that’s the purpose of a pump.