 Ascent Professor, Department of Mechanical Engineering, Walton Institute of Technology, Solaapur. So, today we are going to discuss the basic graphs of steam. So, at the end of this lecture, students will be able to understand the temperature enthalpy diagram of steam and also the moly diagram. So, just it is a continuation of the previous graph which are discussed, the formation of steam. So, in that I have represented this particularly as a this particular portion as A, B, C, D. In the previous case you are taken as a A, B, C, D. So, it is just a continuation with that one as, so this is A, B, C, D. The same graph I have taken in addition to this one, this side the location up to this particularly point is as a water, that is a saturation temperature of water this side. And this is this side is nothing but a superheated side. So, in between this graph this is we are going to represent it only for the one atmospheric pressure. So, here if you refer it here, this 1 to 2 is the water is heated from T1 to T2 temperature. So, water is going to be heated from T1 to T2 temperature. And from here this is water vaporization start from point 2 to 3, it is just a continuation of our previous lecture. So, here so this is decreasing content of water is going to be shown here. So, just you can observe this particularly graph. So, this length it is for representing for only one atmospheric pressure. If it goes in the upward direction the pressure is going to be increasing. So, whenever this particular line if you are going to take it here that is at a higher pressure and if you are coming in the downward direction it is at a lower pressure you are going to consider it. So, here the temperature is goes on increasing in the upward direction and here the enthalphees goes on increasing in the right hand side from the x axis. Here in this particular portion the detailed discussion in this particularly content is the content of water as well as steam. And here it is a stupper heat test stage. So, the same thing the graph for reference I have taken in detail in the previous lecture about A, B, C, D. A representing the portion of this particularly as the liquid status and this B point is representing as the initial stage of conversion of water into vaporization. So, this phase is a combination of water as well as the steam portion and when it come to this C point. So, here the saturation of vaporization it is going to be converted into a steam into a superheated stage to the point as a D point. This is C D point this particular portion and this particular portion. So, the representation I have taken piston and cylinder arrangement comparing with this particular graph. So, the next part is very important in this particularly the steam formation. Next we are going to shift it to the Mollier diagrams. Before that one just you can observe it here the temperature is given from here as a 0 degree centigrade up to 374 point 15 degree centigrade. So, here in this particular this particular point you are going to be calling it as a critical parameters at this particular point whatever may be the temperature pressure all these parameters related with this particular point as a critical parameters. So, here just you can observe it here as a. So, this pressure is a P pressure and this is P1 pressure and this is P2 pressure the representation we are given it. So, here the point is given as B point B1 point and this is B2 point. So, just you observe in this particularly as here it is in this particularly the water stage. So, water is converted into a partially steam the same graph I am this one enlarged in the next step this particular graph only. Here just suppose if you are going to draw the different graphs at a particularly position of P1, P2, P3 like this pressures. So, when it reaches this one this you are going to be calling it as a critical pressure that is PC pressure. So, just you remember this my the continuation of lecture in this particular I am going to be discussing of a Benson boiler also in this particular position we will discuss that detail in the next point. So, here coming to this one as enthalpy in this one pressure when it goes on increasing in this way. So, this graph is going to be a narrow this particularly point. So, this portion you are going to be calling it as a saturation it as a saturation points of water and this portion you are going to be calling it as a saturation points of the steam. So, right side of this one is in the superheated stage and left side of this one in the water condition in between that one the it is having as a partially this one as water and partially the steam. So, here this is a dryness fraction one more term is going to be added in this one as a dryness fraction. So, it is a percentage of the P1 steam as well as a water content is going to be defined in this particular area we are going to discuss that part in coming next slide. So, here this particularly is representing it as a hfg and this is hf this are representing as enthalpy of fluid and enthalpy of gaseous as well as a fluid means the water as well as steam will be there. So, here coming to this one this particular point. So, this particular point notation as hg it is a enthalpy of gas. So, this notations I already explained in the h is equal to Cp dt equation. So, based on that one you are going to be finding it as what exactly the value of hf hfg and hg also these three terms you are going to be studying in this particularly the portion. So, this particular whenever the pressure is increasing this is going to reaching this particular these all cap parameters we are going to discuss in the next condition. So, now the graph once again there will be a little bit changes in the next stage with the Mollier diagrams. So, when you are coming to this particularly as a Mollier diagrams. So, this particular part we are going to be taken it as the saturation line this saturation line you are going to be representing in the Mollier diagram as. So, this line this is a saturation line. So, below this portion the steam will be there in the condition of water as well as a steam part or a saturation steam. So, here there will be a dryness fraction here there will be a dryness fraction. So, those dryness fraction is representing in this particular line. So, here your attention is required and this particularly the graph. So, it is a typical graph we are going to be using it for a calculation of different properties of the steams are concerned and different positions. So, coming to this one just you can observe it this type of the lines are representing it as a critical temperature lines these are critical temperature lines. So, when you go in the upward direction the temperature is goes on increasing from 150, 200 to 50 like this you are going to be getting the different temperatures. So, this is representing the position of the dryness fraction. So, right with this particularly x is equal to 0.6, 0.7, 0.8 like this. So, when it crosses this particularly the point. So, there you are going to get it as this particularly as the superheated stage after this one the steam will be there as a superheated steam. So, here considering it as the superheated steam. So, all the properties of the superheated steam you are going to consider it. So, here so just you can observe in this particularly I have noted one point in this particularly this particular notation I given a one point corresponding enthalpy you can get it in this particular position corresponding enthalpy you are going to get it in this position. So, when it comes to this particularly in the line. So, this graph will give a lot of information related to the steam when you are going for the nozzle turbine all the numericals are concerned. So, just I will give for your reference the one more point as just I have shown it is a vertical in the downward direction the corresponding points just you can observe p1 is one this one it is represented as a 12 bar. So, this is at a position of a 12 bar just for your reference this is h1 value if you come in the downward direction for notation of the position of the point 2 point 1 is there in the superheated stage and point 2 is there in the having some dryness fraction it is below the saturation line below the saturation line. So, that is indicating the value of h2 just I have given a 1 2 as a notations we are going to get this information for calculation of the nozzle part we will see the details in the my series of lectures in the next lecture. So, p2 representing it as a 6.548 bar. So, if you observe it this vertical lines as you can observe it. So, these particular lines these particular lines are representing it as a constant pressure line. So, this particular position it is a pressure as a 12 bar when it comes to this one pressure as a 6.548. So, just it is a reference for you how to read the Mollier diagrams when it comes to this particular point this lines if you are going to consider this type of the lines. So, those are indicating at this particularly point as a position of p3 that is a 1.2 bar. So, just the identification of pressures I have given it in this particular point. So, here just my one more the bit as so can you get a specific volume at that particularly the position of any one of the point here point 2 just you can understand the specific volume. So, there is a one more dotted lines you are observing those are representing it as the specific volumes. So, corresponding to this particular point what is a specific volume? So, that is as 0.3 meter cube per kg like this all the properties you are going to be identifying in this Mollier diagram. So, this one you are going to be converting into a tabular form that is nothing but a steam table. Thank you.