The following lines are given Mollier Diagram:

(i) Constant h – lines (horizontal)

(ii) Constant s -lines (vertical lines)

(iii) Constant P- lines

(iv) Constant v -lines

(v) Constant t -lines

(vi) Constant x -lines.

**11.8.1 Isentropic Process (s = c)**

**Point 1:** Intersection of P_{1} & t_{1} (initial point located).

**For point 2:** As s =constant, we draw vertical line from 1 to intersect P_{2} (given) at 2.

It is observed (as an example) the steam is wet at 2, with dryness fraction of x_{2} ( < x_{1}). The enthalpy drop h_{1} – h_{2} may be read out from the chart.

**11.8.2 Throttling Process (h = const.)**

**Point 1** : Intersection of P_{1} and x_{1} (given).

**For point 2:** Draw horizontal line to meet P_{2} at 2.

For example, it is seen from the diagram that the steam at point 2 is superheated.