# Two tank system

1. Feb 23, 2016

### Domagoj

I am currently working on something and I would like to know something. When we connect two tanks and we have water flowing into Tank 1.
Is it possible to make a connection between Tank 1 and Tank 2 so the water level in Tank 2 is higher than water level in Tank 1?

2. Feb 23, 2016

### Staff: Mentor

Welcome to the PF.

As long as the connection includes a pump...

3. Feb 23, 2016

### Domagoj

Yeah i didnt think there is any other solution except that.... Are there some kind of pumps that dont use electricity (or any other imputs), something that works soley on mechanics, and are those pumps efficient in comparison with electrical pumps?

4. Feb 23, 2016

### Staff: Mentor

What's the application?

5. Feb 25, 2016

### CWatters

What do you mean by "or any other inputs"?

There are hand cranked pumps. Are they allowed?

6. Feb 25, 2016

### Domagoj

there is no application...I just want to find out how things work

7. Feb 25, 2016

### Staff: Mentor

8. Feb 25, 2016

### Domagoj

I have another question that bothers me..... If we have 2 tanks, Tank 1 is lower and Tank 2 is higher and they are connected. If water is flowing in Tank1, will Tank 2 also be filled and if so, are the water heights in both Tanks equal?

9. Feb 25, 2016

### Staff: Mentor

If the water heights are not equal and the tanks are connected, there will be a water pressure difference that will drive water from the higher pressure (higher height) to the lower pressure, until the two heights are equal.

10. Feb 25, 2016

### Domagoj

I understand thank you....One more.... If we use Venturi pipe to connect two tanks, lets say that smaller end goes in Tank 1, and bigger end goes in Tank 2. Lets say that bigger end is twice the size of smaller end of the pipe. Does that affect water levels in Tanks.

11. Feb 25, 2016

### Staff: Mentor

The change in pressure due to the Venturi effect only occurs when the liquid or gas is flowing. So it will affect how quickly the two tank pressures equalize, but won't prevent them from equalizing eventually.

https://en.wikipedia.org/wiki/Venturi_effect

12. Feb 25, 2016

### sophiecentaur

Basically, no, not never ever. You cannot do work without an energy source. All the devices that appear to do that are based on some hidden source of energy (a trick) that is not obvious to the audience. If you define a pump as a device that raises the level of a fluid then all pumps need energy.

13. Feb 25, 2016

### Domagoj

I was reffering to something like this
https://en.wikipedia.org/wiki/Hydraulic_ram

14. Feb 26, 2016

### sophiecentaur

Yes - and a hydraulic ram uses the Power of the water flowing through it. You may regard that as 'free' energy but it's still an energy input. The lower of your two tanks would have to have another outlet, allowing water flow downhill, out of it, to power the Ram.