Can water be liquefied or solidified just by adjusting the temperature, regardless of the pressure?

![enter image description here](https://i.stack.imgur.com/umZXz.png)


technically the line between liquid and solid phase would go a long way before hitting the y-axis, but the point is it will eventually.


So the question remains, can any liquids, including water (with its unique phase diagram) be liquefied regardless of the pressure?


![enter image description here](https://i.stack.imgur.com/aUMxT.jpg)




If I actually understood your question correctly, yes there are regions above which there will be **only** solid state (rather than no solid state). This is limited to the molecular region.


![Phase diagram of water](https://i.stack.imgur.com/Qa2tm.png)


The Roman numerals indicate various ice phases.


From the above phase diagram (which can be found [here](http://en.wikipedia.org/wiki/Phase_diagram#Crystal_phase_diagrams)) the solid-liquid equilibrium line doesn’t touch the y-axis as you suggest. But there will be only solid phase above the $10\ \mathrm{GPa}$ region(approximately). 


In the phase diagram you drew, if (a big if) such a PD exists for some element/molecule, then there will be no solid above the point where solid-liquid line meets y-axis. 


As pointed out in the comments, when we reach high temperatures and pressures we won’t be seeing the molecular water. It will dissociate into atoms/ions as shown in the figure. ![water at high T and p](https://i.stack.imgur.com/BNrkK.jpg)


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Theoretically, **YES**!


**But why?**
In the real world there are a thousand different ways to accomplish a certain task, but only a few will be the most efficient. So in considering your question.



> 
> So the question remains, can any liquids, including water (with its unique phase diagram) be liquefied regardless of the pressure?
> 
> 
> 


First of all, **I do not like how you put regardless of the pressure**, there has to be a certain amount of pressure. Yes you can do this, but there really is an easier way to this. Use a freezer to solidify it, or leave it out in the open to liquify it. :)


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