Fluidsystem: purewatersimple.hh - who, why, what!?

Has anyone ever used purewatersimple.hh and what is it good for? It has (strange) hardcoded values for almost anything. The description says it is solely H2O, but e.g. still uses some N2-values or fugacity-coefficients.

What should we do with it? As far as we know it is only used in the mpnc combustionproblem1c.hh