Follow Up ON Water Treatment

Steve Fessette

I posted a question on the PH level being very high in our boilers, and thanks to you folks I discovered that you don"t use softened water for make-up water. My next question is does chlorinated water have any affect on the water in a steam boiler?

Rod

Chlorinated Water

Hi- Interesting question!  I can only think that if chlorinated water was a problem, 99 percent of us would have experienced problems. It is, however, important after adding new water to the boiler to bring the water in the boiler to the boil to drive off excess dissolved oxygen. Boiling the water may also dissipate most of the chlorine. 

- Rod

Dave in QCA

Chlorine Dissipates

Rod is correct.  Chlorine dissipates from the water and causes no harm to the boiler.  This is not to be confused with Chloride.  High Chloride levels can be very harmful to cast iron boilers, causing rotting at the water line. 

A pH that is slightly alkaline, (higher than 7) is desirable.  Alkalinity does not cause deterioration of the iron, acidity does.  However, excess alkalinity will cause foaming an other problems, and so a compromise is desirable.Companion guide to the ASME boiler & pressure vessel code

Recommends a pH level between 7 and 11.