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Latent heat of water phase changes changes with pressure - at critical point it's zero. At atmospheric pressure, it's given by countless tables all over the net. I can read the pressure and temperature of the phase change for a range of pressure values from the diagram too. But I never found any resource that would show how the latent heat value changes.

Could someone provide some table, equation, graph that gives these values? I would prefer an answer in joules if possible. If you can provide values for a range of pressures, that would be even more welcome, but I specifically want the latent heat of fusion and vaporization of water at 620Pa?

And if that was to be too hard, maybe provide just the values right at the edge of the triple point - if liquid water at just above 0 Celsius degrees is depressurized from 620 to 610Pa, how much of it will evaporate and how much will freeze?

I'm aware of a previous question here, which asks about the general effect of pressure on latent heats and the mechanisms behind said changes. Here I'm asking for a specific reference to the values for water as a function of pressure, and particularly for pressures as low as 620 Pa (which is too low for most obvious search results).

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  • $\begingroup$ @sammygerbil: No! That question asks just for explanation of the effect. I'm asking for numbers - values - tables or graphs. I've even linked that very question from mine, because it doesn't have anything I don't know! The only numbers there are ginen in this answer and they are for 1 bar, which as I said, is ubiquitously available. Why do people here lack the ability of reading comprehension?! I'm not asking for explanation, I'm asking for data for calculations! $\endgroup$ – SF. Aug 19 '16 at 20:49
  • $\begingroup$ Sorry, you're right. Such requests for tables of data don't often get answers here, but no harm trying. A chemical engineer might know, but chemistry and engineering SE sites are both much smaller. Otherwise it depends on luck or how good your search skills are. $\endgroup$ – sammy gerbil Aug 19 '16 at 21:37
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    $\begingroup$ @sammygerbil: Sorry for snapping but I think this is my third question in a row I'd posted on Physics.SE on route to closure following exactly the same pattern. "What relativistic effects are observed in X as it approaches relativistic speeds" getting closed as duplicate of "what happens to X if it exceeds speed of light" (for which answers are trivial "it can't"). $\endgroup$ – SF. Aug 19 '16 at 22:48
  • $\begingroup$ @Gert: Did you read the question I linked from mine? Did you read the first comment? Did you see what my question link to? Did you spend even a minute to determine what are the differences between my question and the other? Because I swear some people on this site should goback to primary school because they lack the most basic reading comprehension! $\endgroup$ – SF. Aug 20 '16 at 9:59
  • $\begingroup$ The fault is mine, I think, since I first marked your question as a duplicate. So I apologise again. I have voted to re-open, although I think it is now so narrow as to be not useful for the broader community : conceptual questions seem to be the ideal. $\endgroup$ – sammy gerbil Aug 20 '16 at 15:02

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