The X  factor.

If we define the relation :          

MU / FW = X

Then X is the participation of make up at the feed water, and can vary from zero till one.

The participation of condensate is:

1 - X

The X is called make-up ratio, while  1 - X   is condensate ratio.

Operators are using the terms % make up and % condensate which correspond to:

100*X     and     100*(1-X).

The X factor, even being hydraulic characteristic of the process, can be calculated every moment from the chemical analysis of the water.

Taking into consideration a water analysis constituent which comes into the circuit only through make-up and leaves only through blowdown and losses, is not transformed, destroyed or precipitates, like chloride ion, then its material balance for the feed water will be:

MU * CLMU + C * CLC = FW * CLFW

or

MU/FW * CLMU + C/FW * CLC = CLFW

or

X * CLMU + (1-X) * CLC = CLFW

and finally:     

                                                    CLFW-CLC

                                          X= -----------------       (d)

                                                     CLMU-CLC

So from the water analysis of make up, feed water and condensate we can calculate the  factor from equation (d).

If there is not priming or carry-over, CLC=0. In any case, when:

CLC > CLMU

Condensate has to be rejected.

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